Article

Degradation of benzo[ a ]pyrene by bacterial isolates from human skin

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Abstract

Polycyclic aromatic hydrocarbons (PAHs) are some of the most widespread xenobiotic pollutants, with the potentially carcinogenic high molecular weight representatives being of particular interest. However, while in eukaryotes the cytochrome P450-mediated activation of benzo[a]pyrene (B[a]P) has become a model for metabolism-mediated carcinogenesis, the oxidative degradation of B[a]P by microbes is less well studied. This should be reason for concern as the human organ most exposed to environmental PAHs is the skin, which at the same time is habitat to a most diverse population of microbial commensals. Yet, nothing is known about the skin's microbiome potential to metabolise B[a]P. This study now reports on the isolation of 21 B[a]P-degrading microbes from human skin, 10 of which were characterised further. All isolates were able to degrade B[a]P as sole source of carbon and energy and degradation was found to be complete in at least 4 isolates. Substrate metabolism involved two transcripts that encode a putative DszA/NtaA-like monooxygenase and a NifH-like reductase, respectively. Analysis of the 16S-rRNA genes showed that the B[a]P-degrading isolates comprise Gram(+) as well as Gram(-) skin commensals, with Micrococci being predominant. Moreover, microbial B[a]P degradation was detected on all volunteers probed, indicating it to be a universal feature of the skin's microbiome. This article is protected by copyright. All rights reserved.

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... Beyond extensively characterised immunomodulation dysbiosis of the skin's microbiome has been associated with conditions such as atopic dermatitis or allergies and recent work highlighted the potential of skin commensals to form highly carcinogenic by-products from benzo[a]pyrene and other polycyclic aromatic hydrocarbons (Platzek et al. 1999;Sowada et al. 2014;Stingley et al. 2010). Yet, for many of the observed microbial dysbalances it still remains unclear if they are cause or rather consequence of the respective condition (Tralau et al. 2015). ...
... Yet, for many of the observed microbial dysbalances it still remains unclear if they are cause or rather consequence of the respective condition (Tralau et al. 2015). Even the presumably more straightforward hazard of carcinogenic metabolites remains challenging to assess, not the least due to the aforementioned lack of suitable model systems (Sowada et al. 2014(Sowada et al. , 2017. We now report on the development of a test system designed to study skin-microbe interactions in situ. ...
... Moreover, the model was previously pre-validated for metabolically competent toxicity testing in vitro (Brinkmann et al. 2013;Hu et al. 2010) and genotoxicity testing using micronucleus and COMET assays (Pfuhler et al. 2014). In a proof-of-concept, this model has now been colonised using two previously isolated skin isolates, namely Micrococcus luteus 1B and Pseudomonas oleovorans 1C (Sowada et al. 2014). The selection of these organisms followed practical considerations and with the intended later application of studying potential microbiome-mediated substance toxification in mind. ...
Article
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The skin`s microbiome is predominantly commensalic, harbouring a metabolic potential far exceeding that of its host. While there is clear evidence that bacteria-dependent metabolism of pollutants modulates the toxicity for the host there is still a lack of models for investigating causality of microbiome-associated pathophysiology or toxicity. We now report on a biologically characterised microbial–skin tissue co-culture that allows studying microbe–host interactions for extended periods of time in situ. The system is based on a commercially available 3D skin model. In a proof-of-concept, this model was colonised with single and mixed cultures of two selected skin commensals. Two different methods were used to quantify the bacteria on the surface of the skin models. While Micrococcus luteus established a stable microbial–skin tissue co-culture, Pseudomonas oleovorans maintained slow continuous growth over the 8-day cultivation period. A detailed skin transcriptome analysis showed bacterial colonisation leading to up to 3318 significant changes. Additionally, FACS, ELISA and Western blot analyses were carried out to analyse secretion of cytokines and growth factors. Changes found in colonised skin varied depending on the bacterial species used and comprised immunomodulatory functions, such as secretion of IL-1α/β, Il-6, antimicrobial peptides and increased gene transcription of IL-10 and TLR2. The colonisation also influenced the secretion of growth factors such as VFGFA and FGF2. Notably, many of these changes have already previously been associated with the presence of skin commensals. Concomitantly, the model gained first insights on the microbiome’s influence on skin xenobiotic metabolism (i.e., CYP1A1, CYP1B1 and CYP2D6) and olfactory receptor expression. The system provides urgently needed experimental access for assessing the toxicological impact of microbiome-associated xenobiotic metabolism in situ.
... These include PAHs and nitrosamines, which have received the most attention because they are pro-carcinogens. Given that studies have revealed the existence of environmental microorganisms that have the ability to metabolize PAHs, 12-14, 15 ,16-22 and that bacteria with similar qualities exist on human skin 21,23 , we looked for evidence of the same in the oral cavity. We used the same method for selection of environmental microbes, obtained for example from petroleum waste sites, that have the ability to survive long term in minimal media with PAHs as the sole carbon Page 3/23 source 15,17,21,24 . ...
... Given that studies have revealed the existence of environmental microorganisms that have the ability to metabolize PAHs, 12-14, 15 ,16-22 and that bacteria with similar qualities exist on human skin 21,23 , we looked for evidence of the same in the oral cavity. We used the same method for selection of environmental microbes, obtained for example from petroleum waste sites, that have the ability to survive long term in minimal media with PAHs as the sole carbon Page 3/23 source 15,17,21,24 . In the current work, microorganisms were harvested from the oral mucosa surfaces and then exposed over weeks in vitro to a cocktail of PAHs with no other carbon source to determine if smokers preferentially harbored microbes tolerant of tobacco smoke PAHs. ...
... In this experiment the PAHs tested were phenanthrene and pyrene. These chemicals were chosen because they can be found at relatively high levels in the oral cavity in tobacco users 25,26 and they are readily digested by many environment microbes [13][14][15][16][17][18][19][20][21][22] . A soil-derived strain, Mycobacterium rutilum, capable of metabolizing pyrene or phenanthrene as sole carbon source was used as a positive control. ...
Preprint
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Certain soil microbes resist and metabolize polycyclic aromatic hydrocarbons (PAHs). The same is true for certain skin microbes. Oral microbes have the potential to oxidize tobacco PAHs to increase their ability to cause cancer. We hypothesized that oral microbes that resist high levels of PAH in smokers exist and can be identified based on their resistance to PAHs. We isolated bacteria and fungi that survived long term in minimal media with PAHs as the sole carbon source from the oral cavity in 11 of 14 smokers and only 1 of 6 nonsmokers. Of bacteria genera that included species that survived harsh PAH exposure in vitro , all were found at trace levels on the oral mucosa, except for Staphylococcus and Actinomyces . Two PAH-resistant strains of Candida albicans (C. albicans) were isolated from smokers. C. albicans is found orally at high levels in tobacco users and some Candida species can metabolize PAHs. The two C. albicans strains were tested for metabolism of two model PAH substrates, pyrene and phenanthrene. The result showed that the PAH-resistant C. albicans strains did not metabolize the two PAHs. In conclusion, evidence for large scale oral microbial metabolism of tobacco PAHs by common oral microbes remains lacking.
... Recently, bacterial skin commensals have been demonstrated to degrade different PAHs and related xenobiotic compounds [16,17]. Such reports demonstrate a potential ecological connection between PAH exposure and the microbiota in skin disorders. ...
... Taxa of the same genera were found differentially abundant in the two cities (e.g., OTU_B5 and B10 of Corynebacterium, OTU_B11095 and B2738 of Staphylococcus, and OTU_F4802 and other OTUs of Malassezia were over-represented in Baoding and Dalian, respectively). Micrococcus, Paracoccus, Ralstonia, Novosphingobium, and Aestuariimicrobium (Additional file 2: Figure S2), genera that have been documented to break down PAHs and related compounds [16,[21][22][23][24], were among the taxa enriched in Baoding independent of the skin or scalp type. The majority of the differentially abundant fungal taxa were enriched in Dalian. ...
... For both taxonomic and functional analyses, FDR-adjusted p value (q value) ≤ 0.25 is considered significant as determined by MaAsLin2 commensal microbiota to protect the host against pathogens and maintain skin homeostasis. Given the clinical relevance of pollutant exposure to the skin conditions, and the PAH biodegradation properties of resident skin microbes [16,17], examinations of the interplay between PAH exposure and skin microbiota enable a first understanding of the impacts PAHs and related pollutants have on cutaneous health. ...
Article
Full-text available
Polycyclic aromatic hydrocarbons (PAHs) are of environmental and public health concerns and contribute to adverse skin attributes such as premature skin aging and pigmentary disorder. However, little information is available on the potential roles of chronic urban PAH pollutant exposure on the cutaneous microbiota. Given the roles of the skin microbiota have on healthy and undesirable skin phenotypes and the relationships between PAHs and skin properties, we hypothesize that exposure of PAHs may be associated with changes in the cutaneous microbiota. In this study, the skin microbiota of over two hundred Chinese individuals from two cities in China with varying exposure levels of PAHs were characterized by bacterial and fungal amplicon and shotgun metagenomics sequencing. The results in this study demonstrated the changes in composition and functional capacities of the cutaneous microbiota associated with chronic exposure levels of PAHs. Findings from this study will aid the development of strategies to harness the microbiota in protecting the skin against pollutants.
... For N. pentaromativorans US6-1 it was reported that the HBMO gene coding for the enzyme 4-hydroxybenzoate 3-monooxygenase gets overexpressed after the incubation with BaP during 12 h (Lyu et al., 2014). Other studies have been shown that B. licheniformis grows in the presence of BaP, inducing the expression of genes coding for monooxygenases (Sowada et al., 2014). There are several reports about BaP metabolism, however most of them focus on the physical and chemical aspects, reporting the intermediary metabolites that are generated. ...
... There are several reports about BaP metabolism, however most of them focus on the physical and chemical aspects, reporting the intermediary metabolites that are generated. But little is known about the genetic processes involved in the BaP degradative pathways (Kanaly and Harayama, 2000;Moody et al., 2004;Lyu et al., 2014;Sowada et al., 2014). ...
... This protein has been described in Gram-positive bacteria and participates in the fatty acid and polyunsaturated fatty acid biosynthesis (Zaccai et al., 2008;Johnson et al., 2011). As mentioned before it is known that the metabolism of high molecular weight PAHs, specifically that of the BaP, involves the cleavage of 2 or more benzene rings by monooxygenases like enzymes (Kweon et al., 2011;Sowada et al., 2014). In this study we identified two strains harboring in the plasmids to the genes pobA (H23) and fabHB (H38), enconding for the enzymes 4-hydroxybenzoate 3-monooxygenase and the ketoacyl-ACP synthase III, respectively. ...
Article
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Bacillus licheniformis M2-7 is a heat-resistant bacterium able to biotransform polycyclic aromatic hydrocarbons. It can transform a wide range of these compounds as naphthalene, phenanthrene, pyrene and benzo[a]pyrene. Benzo[a]pyrene is a polycyclic aromatic hydrocarbon of high molecular weight considered as potentially toxic and carcinogenic for humans. Aiming to discover the genes involved in the biotransformation of benzo[a]pyrene, we made a B. licheniformis M2-7 genomic library in E. coli. We isolated two E. coli strains that were able to grow in minimal salt medium supplemented with benzo[a]pyrene. From the analysis of the DNA fragments in the clones H23 and H38, we identified open reading frames coding for 5 possible genes, among them pobA and fabHB, which products are the enzymes 4-hydroxybenzoate 3-monooxygenase and the ketoacyl-ACP synthase III, respectively. To evaluate the role of these genes in the metabolism of benzo[a]pyrene in B. licheniformis M2-7, we estimated their relative expression through reverse transcription quantitative PCR. Finally, we observed that the genes pobA and fabHB were overexpressed after 3 h under induction with benzo[a]pyrene, suggesting that this strain could use these genes during the metabolism of this PAH, plus it does it in a faster time than that reported for other bacterial genera.
... Recently, bacterial skin commensals have been demonstrated to degrade different PAHs and related xenobiotic compounds [16,17]. Such reports demonstrate a potential ecological connection between PAH exposure and the microbiota in skin disorders. ...
... Taxa of the same genera were found differentially abundant in the two cities (e.g., OTU_B5 and B10 of Corynebacterium, OTU_B11095 and B2738 of Staphylococcus, and OTU_F4802 and other OTUs of Malassezia were over-represented in Baoding and Dalian, respectively). Micrococcus, Paracoccus, Ralstonia, Novosphingobium, and Aestuariimicrobium (Additional file 2: Figure S2), genera that have been documented to break down PAHs and related compounds [16,[21][22][23][24], were among the taxa enriched in Baoding independent of the skin or scalp type. The majority of the differentially abundant fungal taxa were enriched in Dalian. ...
... This study highlighted the potential roles pollutant exposure have on various aspects of the skin microbiota, including changes in diversity and abundances of taxa and alteration of the functional potentials that may be important for the commensal microbiota to protect the host against pathogens and maintain skin homeostasis. Given the clinical relevance of pollutant exposure to the skin conditions, and the PAH biodegradation properties of resident skin microbes [16,17], examinations of the interplay between PAH exposure and skin microbiota enable a first understanding of the impacts PAHs and related pollutants have on cutaneous health. Consistent with previous works [4][5][6]28], this study showed that skin site and the cohort residing city played major roles in shaping bacterial and fungal cutaneous communities. ...
Article
Full-text available
Background: Polycyclic aromatic hydrocarbons (PAHs) are of environmental and public health concerns and contribute to adverse skin attributes such as premature skin aging and pigmentary disorder. However, little information is available on the potential roles of chronic urban PAH pollutant exposure on the cutaneous microbiota. Given the roles of the skin microbiota have on healthy and undesirable skin phenotypes and the relationships between PAHs and skin properties, we hypothesize that exposure of PAHs may be associated with changes in the cutaneous microbiota. In this study, the skin microbiota of over two hundred Chinese individuals from two cities in China with varying exposure levels of PAHs were characterized by bacterial and fungal amplicon and shotgun metagenomics sequencing. Results: Skin site and city were strong parameters in changing microbial communities and their assembly processes. Reductions of bacterial-fungal microbial network structural integrity and stability were associated with skin conditions (acne and dandruff). Multivariate analysis revealed associations between abundances of Propionibacterium and Malassezia with host properties and pollutant exposure levels. Shannon diversity increase was correlated to exposure levels of PAHs in a dose-dependent manner. Shotgun metagenomics analysis of samples (n = 32) from individuals of the lowest and highest exposure levels of PAHs further highlighted associations between the PAHs quantified and decrease in abundances of skin commensals and increase in oral bacteria. Functional analysis identified associations between levels of PAHs and abundance of microbial genes of metabolic and other pathways with potential importance in host-microbe interactions as well as degradation of aromatic compounds. Conclusions: The results in this study demonstrated the changes in composition and functional capacities of the cutaneous microbiota associated with chronic exposure levels of PAHs. Findings from this study will aid the development of strategies to harness the microbiota in protecting the skin against pollutants. Video Abstract.
... The azo dyes are regularly used in cosmetics, tattoo inks, and other products, and the reduction of these dyes due to their undesirable metabolism by the skin microbiome-harbored metabolic enzymes can produce carcinogenic aromatic amines, which poses significant health risks (Chung, 1983;Nakayama et al., 1983). Another example is the aerobic oxidative metabolism of an abundant environment pollutant BaP by monooxygenase enzymes from different bacterial species of skin microbiome (Sowada et al., 2014). The anaerobic metabolism of different skin secretion substances such as triglyceride lipids and secretory proteins by lipases and proteases has also been reported by experimental studies (Byrd et al., 2018). ...
... BaP is an abundant environmental pollutant found in almost all types of soot and smoke generated by the incomplete combustion of fossil fuel, coal, and other biomass including tobacco. The metabolism of this polycyclic aromatic hydrocarbon molecule by oxidation reaction through cytochrome P450 enzyme from human host and monooxygenases and dioxygenase enzymes from bacterial species of skin microbiome is known from experimental studies, and reference databases such as the University of Minnesota (Gelboin, 1980;Gibson et al., 1975;Jiang et al., 2007;Schwarz et al., 2001;Sowada et al., 2014). For this molecule, SkinBug correctly predicted its metabolism by skin microbiome as shown by an experimental study from Sowada et al., 2014, and predicted its oxidation by naphthalene 1,2-dioxygenase and monooxygenase enzymes from multiple species of Burkholderia, Polaromonas, Pseudomonas, and Ralstonia genera from the skin microbiome. ...
... The metabolism of this polycyclic aromatic hydrocarbon molecule by oxidation reaction through cytochrome P450 enzyme from human host and monooxygenases and dioxygenase enzymes from bacterial species of skin microbiome is known from experimental studies, and reference databases such as the University of Minnesota (Gelboin, 1980;Gibson et al., 1975;Jiang et al., 2007;Schwarz et al., 2001;Sowada et al., 2014). For this molecule, SkinBug correctly predicted its metabolism by skin microbiome as shown by an experimental study from Sowada et al., 2014, and predicted its oxidation by naphthalene 1,2-dioxygenase and monooxygenase enzymes from multiple species of Burkholderia, Polaromonas, Pseudomonas, and Ralstonia genera from the skin microbiome. This case study further supports the validity, accuracy, and utility of SkinBug tool. ...
Article
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In addition to being pivotal for the host health, the skin microbiome possesses a large reservoir of metabolic enzymes, which can metabolise molecules (cosmetics, medicines, pollutants, etc.) that form a major part of the skin exposome. Therefore, to predict the complete metabolism of any molecule by skin microbiome, a curated database of metabolic enzymes (1,094,153), reactions, and substrates from ∼900 bacterial species from 19 different skin sites were used to develop “SkinBug”. It integrates machine learning, neural networks, and chemoinformatics methods, and displayed a multiclass multilabel accuracy of up to 82.4% and binary accuracy of up to 90.0%. SkinBug predicts all possible metabolic reactions and associated enzymes, reaction centers, skin microbiome species harbouring the enzyme, and the respective skin sites. Thus, SkinBug will be an indispensable tool to predict xenobiotic/biotic metabolism by skin microbiome, and will find applications in exposome and microbiome studies, dermatology, and skin cancer research.
... Some of the bacterial genes for the respective underlying metabolic pathways were identified and shown to be detectable in situ on human skin, as were the associated bacteria. Concomitantly carbon-limited batch cultures showed the corresponding bacterial metabolism of B[a]P to result in the formation and excretion of highly cytotoxic and genotoxic metabolites (26,27). Similar observations have been reported for the intestinal microbiota, where commensals are known to directly metabolize xenobiotic substances, as well as impacting the host's capacity for xenobiotic metabolism by affecting phase I and phase II enzymes (28)(29)(30). ...
... The aim of the study was to investigate the effects of commensal skin colonization on B[a]P-metabolism in situ using a microbially competent 3D skin model (31). The model was colonized with two previously isolated skin commensals, namely, Micrococcus luteus 1B and Pseudomonas oleovorans 1C (26,27). While both organisms have been established using B[a]P as the sole source of carbon and energy, including the metabolites formed by M. luteus, the nature of the metabolites formed by P. oleovorans remained unknown (27). ...
... P. oleovorans B[a]P metabolites. The analytical examination of the respective culture supernatants confirmed this strain's ability to partially metabolize B[a]P (26). The dominant metabolites formed were B[a]P-1,6-dione, B[a]P-7,8-dione, B[a]P-7,10-dione, and 3-OH-B[a]P (Fig. S4A). ...
Article
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Polycyclic aromatic hydrocarbons (PAH) such as benzo[a]pyrene (B[a]P) are among the most abundant environmental pollutants, resulting in continuous exposure of human skin and its microbiota. However, effects of the latter on B[a]P toxicity, absorption, metabolism, and distribution in humans remain unclear. Here, we demonstrate that the skin microbiota does metabolize B[a]P on and in human skin in situ, using a recently developed commensal skin model. In this model, microbial metabolism leads to high concentrations of known microbial B[a]P metabolites on the surface as well as in the epider-mal layers. In contrast to what was observed for uncolonized skin, B[a]P and its metabo-lites were subject to altered rates of skin penetration and diffusion, resulting in up to 58% reduction of metabolites recovered from basal culture medium. The results indicate the reason for this altered behavior to be a microbially induced strengthening of the epider-mal barrier. Concomitantly, colonized models showed decreased formation and penetration of the ultimate carcinogen B[a]P-7,8-dihydrodiol-9,10-epoxide (BPDE), leading, in consequence , to fewer BPDE-DNA adducts being formed. Befittingly, transcript and expression levels of key proteins for repairing environmentally induced DNA damage such as xeroderma pigmentosum complementation group C (XPC) were also found to be reduced in the commensal models, as was expression of B[a]P-associated cytochrome P450-dependent monooxygenases (CYPs). The results show that the microbiome can have significant effects on the toxicology of external chemical impacts. The respective effects rely on a complex interplay between microbial and host metabolism and microbe-host interactions, all of which cannot be adequately assessed using single-system studies. IMPORTANCE Exposure to xenobiotics has repeatedly been associated with adverse health effects. While the majority of reported cases relate to direct substance effects, there is increasing evidence that microbiome-dependent metabolism of xenobiotic substances likewise has direct adverse effects on the host. This can be due to microbial bio-transformation of compounds, interaction between the microbiota and the host's en-dogenous detoxification enzymes, or altered xenobiotic bioavailability. However, there are hardly any studies addressing the complex interplay of such interactions in situ and less so in human test systems. Using a recently developed microbially competent three-dimensional (3D) skin model, we show here for the first time how commensal influence on skin physiology and gene transcription paradoxically modulates PAH toxicity.
... Also, in vitro in a simulated human gut system, bacteria can metabolize BaP to several metabolites ( Van de Wiele et al., 2005). Finally, isolates of bacteria from skin of humans can degrade BaP (Sowada et al., 2018). Dysbiosis of communities of bacteria in the gut can ultimately have direct consequences for the host and alter effects of BaP (Levy et al., 2017;Thaiss et al., 2016). ...
... Enrichment of the PAH degradation pathway in female fish along with bacterial taxa associated with PAH degradation support the hypothesis that bacteria are degrading BaP in female fish. To test this hypothesis that specific strains of bacteria present in the guts of these fish can degrade BaP, Xanthobacteraceae would need to be cultured and exposed to BaP, similar to the study by Sowada et al. (2018), where bacteria cultures from human skin were exposed to BaP and degradation of the BaP was assessed. This would also allow for confirmation that PAH degrading pathways are enriched using transcriptomics rather than the predictive analysis of Tax4Fun2. ...
Article
In addition to aiding in digestion of food and uptake of nutrients, microbiota in guts of vertebrates are responsible for regulating several beneficial functions, including development of an organism and maintaining homeostasis. However, little is known about effects of exposures to chemicals on structure and function of gut microbiota of fishes. To assess effects of exposure to polycyclic aromatic hydrocarbons (PAHs) on gut microbiota, male and female fathead minnows (Pimephales promelas) were exposed to environmentally-relevant concentrations of the legacy model PAH benzo[a]pyrene (BaP) in water. Measured concentrations of BaP ranged from 2.3 × 10⁻³ to 1.3 μg L⁻¹. The community of microbiota in the gut were assessed by use of 16S rRNA metagenetics. Exposure to environmentally-relevant aqueous concentrations of BaP did not alter expression levels of mRNA for cyp1a1, a “classic” biomarker of exposure to BaP, but resulted in shifts in the relative compositions of gut microbiota in females rather than males. Results presented here illustrate that in addition to effects on more well-studied molecular endpoints, relative compositions of the microbiota in the guts of fish can also quickly respond to exposure to chemicals, which can provide additional mechanisms for adverse effects on individuals.
... The solvent cut time was 6 min. Masses monitored by the detector were set as follows: (6)(7)(8) ...
... These results suggest that PMC10 is a promising probiotic candidate with potential PAH degradation efficacy. In a previous study, Paracoccus yeei, Acinetobacter lwoffii, Micrococcus luteus, Staphylococcus caprae, Pseudomonas oleovorans, and Bacillus licheniformis have shown potential BaP-degrading efficacy [6]. Pseudomonas aeruginosa also shows degradation efficacy against Nap [16]. ...
Article
Probiotics are live microorganisms, including bacteria and yeast, which have been demonstrated to have beneficial effects on human health. Since probiotic bacteria have been constantly being studied, applications of probiotics have been considered as promising adjuvant treatment for various intestinal diseases. Clinical trials and in vivo experiments have extended our current understanding of the important roles that probiotics play in human gut microbiome-associated diseases. Many clinical trials have documented that probiotics could shape the intestinal microbiota leading to potential control of multiple bowel diseases to promote overall wellness. In this review, we focused on the relationship between probiotics and the human gut microbiota and its roles in gut microbiome-associated diseases. Here, we also discussed future directions and research areas that need further elucidation in order to better understand the roles of probiotics in the treatment of intestinal diseases.
... Cette liaison induit le recrutement de la machinerie transcriptionnelle et la transcription des gènes XRE impliqués dans la modulation de la prolifération cellulaire, l'inflammation et la mélanogenèse cutanée(Mancebo and Wang, 2015;Koohgoli et al., 2017).• Altération du microbiote cutanéUn nombre grandissant d'études souligne indépendamment l'impact délétère des polluants atmosphériques sur des bactéries isolées et sur la peau directement, peu d'études traitent de l'impact de la pollution sur le microbiote cutané(Sowada et al., 2014;Araviiskaia et al., 2019).Une nouvelle approche consiste à considérer l'altération du microbiote cutané par les polluants comme une action indirecte de ces polluants sur la peau. Une première étude par méthodes culturales de He et al. a permis de démontrer que l'O3 avait un effet bactéricide et entrainait une réduction de 50% de la densité du microbiote bactérien cutané résident(He et al., 2006). ...
... métabolisme des glucides, lipides et acides aminés) ainsi qu'une augmentation du potentiel pathogène. Ces études ont également démontré que certaines bactéries de la peau peuvent métaboliser les HAP en produits bénins ou produire des métabolites intermédiaires à toxicité accrue exacerbant l'impact sur le peau(Sowada et al., 2014(Sowada et al., , 2017Leung et al., 2020). De manière plus générale, l'urbanisation est reconnue comme étant un facteur majeur d'altération du microbiote cutané ( §II.4.b).b. ...
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Le dioxyde d’azote (NO2), en tant que second polluant atmosphérique le plus meurtrier en Europe est un des plus préoccupants pour la santé humaine selon l’Agence Européenne de l’Environnement. Il est notamment connu pour être responsable de maladies cardiovasculaires, respiratoires ainsi que pour contribuer au vieillissement cutané et au développement de la dermatite atopique. Des facteurs endogènes à l’hôte tels que le microbiote cutané interviennent également dans cette pathologie. En effet, de nombreuses pathologies cutanées sont corrélées à un déséquilibre (dysbiose) du microbiote bactérien, un acteur essentiel du maintien de l’homéostasie de la peau. Or, il est fortement soupçonné que l’effet des polluants sur la peau implique des mécanismes d’action directe mais également un mécanisme d’action indirecte lié à l’altération du microbiote cutané par le polluant. En conséquence, il est pertinent d’aborder l’effet du NO2 gazeux (gNO2) sur le microbiote cutané bactérien. Cette thèse a donc pour objectif d’évaluer l’impact physiologique, morphologique et moléculaire du NO2 sur des souches bactériennes commensales d’espèces représentatives du microbiote cutané (Staphylococcus aureus, Staphylococcus epidermidis, Staphylococcus capitis, Pseudomonas fluorescens, Corynebacterium tuberculostearicum). Selon l’espèce, des réponses différentes au stress nitrosant généré par le gNO2 ont ainsi été mises en évidence ainsi qu’une tolérance plus importante au gNO2 pour certaines d’entre elles. Ces travaux suggèrent par conséquent que le NO2 pourrait contribuer à la formation d’un état dysbiotique du microbiote cutané et participer à l’action indirect du polluant sur la peau.
... The bacterial isolates include (1 Figure S1 shows the phylogenetic trees of the identified bacteria based on their 16S rRNA gene sequences. Four bacterial species were identified, i.e., Paracoccus yeei, Pseudomonas geniculate, Microbacterium laevaniformans, and Pseudomonas stutzeri which are known to be widely distributed in PBDE/ECs-contaminated soil (Chou et al. 2013;Sowada et al. 2014;Wu et al. 2018). ...
... Microbacterium sp. have been shown to biodegrade BDE-47 as sole carbon source under aerobic condition (Zhang et al. 2013a). A Stenotrophomonas strain isolated from soils at a PBDEs-contaminated e-waste recycling site was able to effectively degrade BDE-209 (55.15% of 65 μg l -1 ) under aerobic conditions during a 30-day incubation (Wu et al. 2018), and Paracoccus yeei has been shown to utilize benzo[a]pyrene as a sole carbon and energy source (Sowada et al. 2014). UVA irradiation can adversely affect microbial activity and hence inhibit biochemical reactions in the NBB. Figure 3 shows that the number of bacteria present during the coupled UV photolysis-biodegradation process is less than for biodegradation alone. ...
Article
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The commercial flame retardant is an emerging contaminant (EC) commonly found in soils and sediments. A coupled UV-photolysis-biodegradation process was used to decompose decabromodiphenyl ether (BDE-209) in clay slurries. A novel bioslurry bioreactor (NBB) was employed in which BDE-209 degradation was maximized by the simultaneous application of LED UVA irradiation and biodegradation by a mixed bacterial culture. The rate of BDE-209 degradation decreased in the order: coupled UV photolysis-biodegradation (1.31 × 10-2 day-1) > UV photolysis alone (1.10 × 10-2 day-1) > biodegradation alone (1.00 × 10-2 day-1). Degradation intermediates detected included hydroxylated polybrominated diphenylethers, partially debrominated PBDE congeners and polybrominated dibenzofuran. The UV-resistant bacterial strains isolated that could utilize BDE-209 as a sole carbon source included Stenotrophomonas sp., Pseudomonas sp., and Microbacterium sp. These strains encoded important functional genes such as dioxygenase and reductive dehalogenases. Continuous UV irradiation during the NBB process affected various biochemical oxidative reactions during PBDEs biodegradation. Simultaneous photolysis and biodegradation in the NBB system described reduces operational time, energy, expense, and maintenance-demands required for the remediation of BDE-209 when compared to sequential UV-biodegradation process or to biodegradation alone.
... Some species of the genus Bacillus are well known to degrade hydrocarbons, pyrene, and other PAH (Sowada et al. 2014). B. thuringiensis strain was able to degrade anthracene (Tarafdar et al. 2017), whereas B. thuringiensis B3, and B. cereus B6, were able to live and metabolize crude oil-contaminated sites in Ecuador, metabolizing PAHs from diesel. ...
... The alternative metabolism to degrade benzo [a] pyrene was previously proved by Sowada et al. (2014), who isolated B. licheniformis from human skin, and showed their metabolic capabilities, degrading BaP under mesophilic conditions. Another work supporting this metabolic diversity was that of Bahuguna et al. (2012), which analyzed growth kinetics of B. licheniformis BMIT5ii MTCC 9446 able to grow on naphthalene (0.5 mg/mL). ...
Article
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Petroleum derivates used in energy production are gravely pollutants for the ecosystem, especially for aquatic environments and human health. This study aimed to isolate hydrocarbons-degrading bacteria from hot springs. Three strains of hydrocarbondegrading bacteria strains, belonging to the Bacillus and one of the genus Lysinibacillus were isolated. These strains tolerate temperatures from 65 to 100 ºC and were able to degrade and grow on BH medium supplemented with gasoline and diesel. Strain M2-7 shared 100 % 16S rRNA identity with Bacillus licheniformis and was the only able to degrade pyrene and benzopyrene among these isolated strains. The results indicate that B. licheniformis M2-7 could degrade a wider range of hydrocarbons and some recalcitrant hydrocarbon components, which could be particularly helpful for the treatment and bioremediation of hydrocarbon-polluted systems.
... although two reports now show evidence that bacterial strains isolated from a contaminated site and human skin can (Kaushish Lily et al. 2009;Sowada et al. 2014). ...
... Another interesting finding which may start a new area of study was bacteria isolated from human skin, predominately M. luteus, is capable of utilizing BaP as a carbon source, with no indication if the intermediates may cause oxidative damage, or carcinogenic effects to the host (Sowada et al. 2014). It is unknown if products of BaP degradation with cis conformations are less toxic than those metabolized by eukaryotes, so questions about human exposure to toxic metabolites from bacteria residing on the skin remain. ...
Article
The growing release of organic contaminants into the environment due to industrial processes has inevitably increased the incidence of their exposure to humans which often results in negative health effects. Microorganisms are also increasingly exposed to the pollutants, yet their diverse metabolic capabilities enable them to survive toxic exposure making these degradation mechanisms important to understand. Fungi are the most abundant microorganisms in the environment, yet less has been studied to understand their ability to degrade contaminants than in bacteria. This includes specific enzyme production and the genetic regulation which guides metabolic networks. This review intends to compare what is known about bacterial and fungal degradation of toxic compounds using benzo(a)pyrene as a relevant example. Most research is done in the context of using fungi for bioremediation, however, we intend to also point out how fungal metabolism may impact human health in other ways including through their participation in microbial communities in the human gut and skin and through inhalation of fungal spores. This article is protected by copyright. All rights reserved.
... In addition, the investigation of microbial metabolism should not be restricted to the gut but should also cover other microbiomes. For instance, skin bacteria can degrade toxic polycyclic aromatic hydrocarbons (PAHs) and reduce host exposure [16]. ...
Article
Abstract Xenobiotic metabolism by bacteria inhabiting the gastrointestinal tract has a major influence on health. The large genetic and enzymatic repertoire carried by gut microbial communities provide them with the ability to affect the therapeutic efficacy, toxicity and pharmacokinetic parameters of many chemicals. The gut microbiome is a promising source of drug targets and non-invasive biomarkers, for the early detection of diseases and personalized medicine against cancer. A large number of animal species, including humans, have evolved to feed on toxic or indigestible plants by carrying xenobiotic-degrading microbial communities. Vertical transmission of gut microbiome metabolic capabilities to future generations could even be a mode of transgenerational inheritance. Changes in human gut microbiome composition have been implicated in a wide range of clinical conditions, some of which develop locally in the intestine, such as Crohn's disease, but many others occurring at distant sites, such as metabolic diseases. Recent advances in next-generation sequencing have opened new avenues to determine the role of microbiomes in the toxicity of chemicals, expanding the field of genomic toxicology to a broader metagenomic toxicology research area. In this review, we present key gut-microbiome research areas with a focus on metabolism of xenobiotics by the gut microbiome.
... Micrococcus is one of the most common PAH-degrading bacterial isolates (Nwachukwu et al. 2001). An analysis of 16S rRNA genes from human skin also showed that the B[a]P-degrading isolates comprise Gram(+) as well as Gram(−) skin commensals, with Micrococcus being predominant (Sowada et al. 2014). In addition, Bacillus-like genera (Firmicutes) in the atmosphere were correlated with 3-4 ring PAHs, including Ant, Fla, Flu, and Phe. ...
Article
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The purpose of this study was to investigate the association among polycyclic aromatic hydrocarbons (PAHs) exposure and air pollutants and the diversity of microbiota. Daily average concentrations of six common air pollutants were obtained from China National Environmental Monitoring Centre. The PAHs exposure levels were evaluated by external and internal exposure detection methods, including monitoring atmospheric PAHs and urinary hydroxyl-polycyclic aromatic hydrocarbon (OH-PAH) metabolite levels. We analyzed the diversity of environmental and commensal bacterial communities with 16S rRNA gene sequencing and performed functional enrichment with Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) and Kyoto Encyclopedia of Genes and Genomes (KEGG). Correlation analysis and logistic regression modeling were conducted to evaluate the relationship of PAHs levels with air pollutants and microbial diversity. Correlation analysis found that the concentrations of atmospheric PAHs were significantly positively correlated with those of PM10, NO2, and SO2. There also was a positive correlation between the abundance of the genus Micrococcus (Actinobacteria) and high molecular weight PAHs, and Bacillus, such as genera and low molecular weight PAHs in the atmosphere. Logistic regression showed that the level of urinary 1-OHPyrene was associated with childhood asthma after sex and age adjustment. The level of urinary 1-OHPyrene was significantly positively correlated with that of PM2.5 and PM10. In addition, the level of 1-OHPyrene was positively correlated with oral Prevotella-7 abundance. Functional enrichment analysis demonstrated that PAHs exposure may disturb signaling pathways by the imbalance of commensal microbiota, such as purine metabolism, pyrimidine metabolites, lipid metabolism, and one carbon pool by folate, which may contribute to public health issues. Our results confirmed that atmospheric PAHs and urinary 1-OHPyrene were correlated with part of six common air pollutants and indicated that PAHs pollution may alter both environmental and commensal microbiota communities associated with health-related problems. The potential health and environmental impacts of PAHs should be further explored.
... A study of the polyaromatic hydrocarbons, including naphthalene, phenanthrene, pyrene, and benzo(a)pyrene, showed that colon bacteria formed estrogenic metabolites from these compounds. 111 Another group identified bacteria from skin samples that fully degraded benzo(a)pyrene, 113 though some of the intermediate metabolites may be more toxic. 62 Another mechanism by which the microbiome modulates toxicity is by changing the bioavailability of toxicants. ...
Article
There is overwhelming evidence that the microbiome must be considered when evaluating the toxicity of chemicals. Disruption of the normal microbial flora is a known effect of toxic exposure, and these disruptions may lead to human health effects. In addition, the biotransformation of numerous compounds has been shown to be dependent on microbial enzymes, with the potential for different host health outcomes resulting from variations in the microbiome. Evidence suggests that such metabolism of environmental chemicals by enzymes from the host's microbiota can affect the toxicity of that chemical to the host. Chemical-microbial interactions can be categorized into two classes: Microbiome Modulation of Toxicity (MMT) and Toxicant Modulation of the Microbiome (TMM). MMT refers to transformation of a chemical by microbial enzymes or metabolites to modify the chemical in a way that makes it more or less toxic. TMM is a change in the microbiota that results from a chemical exposure. These changes span a large magnitude of effects and may vary from microbial gene regulation, to inhibition of a specific enzyme, to the death of the microbes. Certain microbiomes or microbiota may become associated with different health outcomes, such as resistance or susceptibility to exposure to certain toxic chemicals, the ability to recover following a chemical-induced injury, the presence of disease-associated phenotypes, and the effectiveness of immune responses. Future work in toxicology will require an understanding of how the microbiome interacts with toxicants to fully elucidate how a compound will affect a diverse, real-world population.
... In particular, air pollution includes biological and gaseous contaminants, as well as particulate. Pollution has been reported to exert deleterious effects on the skin in different ways [29]: (a) ultrafine particles can penetrate tissues and localize in mitochondria, thus inducing ROS generation [30]; (b) diesel exhaust particles induce activation of the inflammatory cascade in keratinocytes [31]; (c) pollutants are among the activators of the aryl hydrocarbon receptor (AhR), a cytosolic ligand-activated transcription factor that regulates cellular proliferation, inflammation, and melanogenesis [32]; and (d) pollutants can alter skin microflora [33,34]. Another external stress factor is arsenic. ...
Article
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Exposure to UV light triggers the rapid generation and accumulation of reactive oxygen species (ROS) in skin cells, with consequent increase in oxidative stress and thus in photoaging. Exogenous supplementation with dietary antioxidants and/or skin pretreatment with antioxidant-based lotions before sun exposure might be a winning strategy against age-related skin pathologies. In this context, plants produce many secondary metabolites to protect themselves from UV radiations and these compounds can also protect the skin from photoaging. Phenolic compounds, ascorbic acid and carotenoids, derived from different plant species, are able to protect the skin by preventing UV penetration, reducing inflammation and oxidative stress, and influencing several survival signalling pathways. In this review, we focus our attention on the double role of oxidants in cell metabolism and on environmental and xenobiotic agents involved in skin photoaging. Moreover, we discuss the protective role of dietary antioxidants from fruits and vegetables and report their antiaging properties related to the reduction of oxidative stress pathways.
... Upon colon digestion, but not stomach or small intestine, PAHs exhibit estrogenic activity similar to 17α-ethynylestradiol [80]. As shown by microbial isolates of skin microbiota, benzo[a]pyrene oxidation and degradation serve as a carbon source for bacteria, giving bacteria in a PAH contaminated site-gastrointestinal tract, contaminated soil, or other environment-a competitive advantage over other bacteria [81]. Overall, oxidation of PAHs by P450s in the colon and skin alter the toxicity from carcinogenic to endocrine disrupting due to their estrogenic activity. ...
Article
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Host cytochrome P450s (P450s) play important roles in the bioactivation and detoxification of numerous therapeutic drugs, environmental toxicants, dietary factors, as well as endogenous compounds. Gut microbiome is increasingly recognized as our “second genome” that contributes to the xenobiotic biotransformation of the host, and the first-pass metabolism of many orally exposed chemicals is a joint effort between host drug-metabolizing enzymes including P450s and gut microbiome. Gut microbiome contributes to the drug metabolism via two distinct mechanisms: direct mechanism refers to the metabolism of drugs by microbial enzymes, among which reduction and hydrolysis (or deconjugation) are among the most important reactions, whereas indirect mechanism refers to the influence of host receptors and signaling pathways by microbial metabolites. Many types of microbial metabolites, such as secondary bile acids (BAs), short-chain fatty acids (SCFAs), and tryptophan metabolites, are known regulators of human diseases through modulating host xenobiotic-sensing receptors. To study the roles of gut microbiome in regulating host drug metabolism including P450s, several models including germ-free mice, antibiotics, or probiotics treatments, have been widely used. The present review summarized the current information regarding the interactions between the gut microbiome and the host P450s in xenobiotic biotransformation organs such as liver, intestine, and kidney, highlighting the remote sensing mechanisms underlying gut microbiome-mediated regulation of host xenobiotic biotransformation. In addition, the roles of bacterial, fungal, and other microbiome kingdom P450s, which is an understudied area of research in pharmacology and toxicology, are discussed.
... The resulting amplified regions were sequenced using the Ion Torrent PGM (Life technologies, Carlsbad, CA) sequencing platform, using the Ion PGM™ Hi-Q™, View OT2 Kit and Ion 316™ Chip Kit V2, according to the manufacturer protocols. The raw FASTQ files were processed using QIIME (version 1.9.1) [17] and quality-filtered using Trimmomatic [18]. After removing the chimeras, the sequences were clustered into OTUs (Operational Taxonomic Units) at 97% identity using SILVA/MiDAS database (version 2.1, http://www.midasfieldguide.org). ...
Article
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In the anaerobic process, fat-oil-grease (FOG) is hydrolysed to long-chain fatty acids (LCFAs) and glycerol (GLYC), which are then used as substrates to produce biogas. The increase in FOG and LCFAs inhibits methanogenesis, and so far, most work investigating this inhibition has been carried out when FOG or LCFAs were used as co-substrates. In the current work, the inhibition of methanogenesis by FOG, LCFAs and GLYC was investigated when used as sole substrates. To gain more insight on the dynamics of this process, the change of microbial community was analysed using 16S rRNA gene amplicon sequencing. The results indicate that, as the concentrations of cooking olive oil (CO, which represents FOG) and LCFAs increase, methanogenesis is inhibited. For instance, at 0.01 g. L-1 of FOG, the rate of biogas formation was around 8 ml.L-1.day-1, and this decreased to = 45°C and NaCl > 3% led to a significant decrease in the rate of biogas formation. Microbial community analyses were carried out from samples from 3 different bioreactors (CO, OLEI and GLYC), on day 1, 5 and 15. In each bioreactor, microbial communities were dominated by Proteobacteria, Firmicutes and Bacteroidetes phyla. The most important families were Enterobacteriaceae, Pseudomonadaceae and Shewanellaceae (Proteobacteria phylum), Clostridiacea and Ruminococcaceae (Firmicutes) and Porphyromonadaceae and Bacteroidaceae (Bacteroidetes). In CO bioreactor, Proteobacteria bacteria decreased over time, while those of OLEI and GLYC bioreactors increased. A more pronounced increase in Bacteroidetes and Firmicutes were observed in CO bioreactor. The methanogenic archaea Methanobacteriaceae and Methanocorpusculaceae were identified. This analysis has shown that a set of microbial population is selected as a function of the substrate.
... Recently Sowada et al. (2014) reported that bacterial isolates from human skin (all 21 isolates investigated) degraded benzo[a]pyrene as sole source of carbon and energy demonstrating that not only enzymatic transformations by the skin itself, but from skin-resident bacteria as well represents an important source for metabolic activations and inactivations of xenobiotica. The human skin which spans an area of about 1.8 m 2 harbors more than 200 bacterial genera with up to 10 million bacterial cells/cm 2 (the core microbiome on human skin often being composed of Actinobacteria, Firmicutes, Bacteroidetes and Proteobacteria, these phyla containing thousands of species, some of which having large metabolic versatility) (Mathieu et al. 2013;Tralau et al. 2015). ...
Article
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Studies on the metabolic fate of medical drugs, skin care products, cosmetics and other chemicals intentionally or accidently applied to the human skin have become increasingly important in order to ascertain pharmacological effectiveness and to avoid toxicities. The use of freshly excised human skin for experimental investigations meets with ethical and practical limitations. Hence information on xenobiotic-metabolizing enzymes (XME) in the experimental systems available for pertinent studies compared with native human skin has become crucial. This review collects available information of which—taken with great caution because of the still very limited data—the most salient points are: in the skin of all animal species and skin-derived in vitro systems considered in this review cytochrome P450 (CYP)-dependent monooxygenase activities (largely responsible for initiating xenobiotica metabolism in the organ which provides most of the xenobiotica metabolism of the mammalian organism, the liver) are very low to undetectable. Quite likely other oxidative enzymes [e.g. flavin monooxygenase, COX (cooxidation by prostaglandin synthase)] will turn out to be much more important for the oxidative xenobiotic metabolism in the skin. Moreover, conjugating enzyme activities such as glutathione transferases and glucuronosyltransferases are much higher than the oxidative CYP activities. Since these conjugating enzymes are predominantly detoxifying, the skin appears to be predominantly protected against CYP-generated reactive metabolites. The following recommendations for the use of experimental animal species or human skin in vitro models may tentatively be derived from the information available to date: for dermal absorption and for skin irritation esterase activity is of special importance which in pig skin, some human cell lines and reconstructed skin models appears reasonably close to native human skin. With respect to genotoxicity and sensitization reactive-metabolite-reducing XME in primary human keratinocytes and several reconstructed human skin models appear reasonably close to human skin. For a more detailed delineation and discussion of the severe limitations see the Conclusions section in the end of this review.
... Micrococcus luteus et Bacillus licheniformis sont capables de dégrader et de bioactiver les HAP (Sowada et al. 2017;Sowada et al. 2014). De fait, l'importance et l'influence de la flore commensale cutanée sur l'absorption cutanée et la bioactivation des HAP devront être déterminées. ...
Thesis
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Les hydrocarbures aromatiques polycycliques (HAP) sont des cancérigènes ubiquitaires, produits en mélanges complexes dont la composition varie en fonction de la source d’émission. Classées substances prioritaires de par leur abondance et leur génotoxicité, l’exposition aux HAP des populations se fait notamment par voie cutanée au cours des activités professionnelles. La surveillance biologique de l’exposition (SBE) tient compte de l’absorption cutanée en plus de l’inhalation et identifie les situations d’exposition à risque. Pour estimer l’exposition au Benzo[a]pyrène (B[a]P), cancérogène certain pour l’homme, le dosage du 3-hydroxybenzo[a]pyrène (3-OHB[a]P) et du (±)trans-anti-B[a]P-tétraol (B[a]P-tétraol) a été récemment proposé. L’objectif de cette thèse était d’étudier l’absorption et le métabolisme cutanés du B[a]P mais aussi des mélanges d’HAP en vue de d’améliorer la compréhension de leur génotoxicité et de développer des biomarqueurs pertinents pour estimer les risques sanitaires. La première partie de ce travail a consisté au développement d’un modèle cutané ex vivo simple mais réaliste à partir d’explants de peau humaine. Après la mise au point des méthodes d’extraction et d’analyse adéquates, la toxico-cinétique et le métabolisme cutané de faibles doses de B[a]P ont été étudiés. La pénétration cutanée et le métabolisme du B[a]P sont inversement proportionnels à la dose appliquée. Cependant, les voies de métabolisation sont impactées différemment. Alors que la production du 3-OHB[a]P issu des voies de détoxication est dose-dépendante, la formation du B[a]P-tétraol, produit de l’hydrolyse du métabolite cancérogène ultime du B[a]P, est rapidement saturée. Le B[a]P-tétraol est donc le biomarqueur le plus pertinent pour estimer le risque cancérogène au B[a]P. De plus, la proportion de B[a]P non-métabolisé traversant la peau est extrêmement limitée indiquant que la toxicité de ce composé s’exprime essentiellement localement. La deuxième partie de ce travail a consisté en une synthèse bibliographique centrée sur la biotransformation de 7 autres HAP cancérogènes permettant d’identifier 16 métabolites d’intérêt commercialisés. In fine, le dosage de 10 de ces métabolites, impliqués dans les voies de bioactivation ou de détoxication de 5 HAP, a pu être développé en GC-MS/MS. Le dosage urinaire de ces nouveaux biomarqueurs devrait permettre d’améliorer la SBE des populations aux HAP cancérogènes. Dans la dernière partie de ce travail, l’impact de la composition de mélanges synthétiques ou industriels (extraits de brai de houille et de coke de pétrole) à différentes doses sur l’absorption et le métabolisme cutanés des HAP furent évalués en présence ou non de rayonnements ultraviolets (UV). La pénétration des HAP diminue quand la complexité du mélange et la dose augmentent. Alors que les UV amplifient la pénétration des HAP lors de l’application des mélanges industriels, ils n’ont pas d’effet sur le B[a]P appliqué seul ou sur les mélanges synthétiques. Leur bioactivation décroit sous l’influence des mélanges et des UV, provoquant une accumulation de HAP non-métabolisés dans la peau ce qui pourrait retarder la survenue des effets génotoxiques. A l’instar du B[a]P, la toxicité des autres HAP cancérogènes semble être essentiellement locale et dépendre du scénario d’exposition cutanée. Ce travail souligne l’importance de l’étude des mélanges du fait d’interactions plus complexes que de simples effets additifs.
... Additionally, we showed using GC-MS that compound A is phthalic acid (Fig. 4c), probably generated as an intermediary metabolite during the biotransformation of BaP by M2-7 during the first 3 h of culture. In the results reported by Sowada et al. (2014), the ability of a B. licheniformis strain from skin microbiota to carry out BaP biodegradation/biotransformation was shown. However, even with no characterization of the metabolites present, the supernatants were considered potentially toxic, and the probable reason for the growth decrease of that strain. ...
Article
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Benzo[a]pyrene (BaP) is recognized as a potentially carcinogenic and mutagenic hydrocarbon, and thus, its removal from the environment is a priority. The use of thermophilic bacteria capable of biodegrading or biotransforming this compound to less toxic forms has been explored in recent decades, since it provides advantages compared to mesophilic organisms. This study assessed the biotransformation of BaP by the thermophilic bacterium Bacillus licheniformis M2-7. Our analysis of the biotransformation process mediated by strain M2-7 on BaP shows that it begins during the first 3 h of culture. The gas chromatogram of the compound produced shows a peak with a retention time of 17.38 min, and the mass spectra shows an approximate molecular ion of m/z 167, which coincides with the molecular weight of the chemical formula C6H4(COOH)2, confirming a chemical structure corresponding to phthalic acid. Catechol 2,3-dioxygenase (C23O) enzyme activity was detected in minimal saline medium supplemented with BaP (0.33 U mg−1 of protein). This finding suggests that B. licheniformis M2-7 uses the meta pathway for biodegrading BaP using the enzyme C23O, thereby generating phthalic acid as an intermediate.
... Report from the simulation of human microbiota shows that colonic human bacteria are also capable of biotransforming polyaromatic compounds such as naphthalene, phenanthrene, pyrene, and benzo[a]pyrene. Micrococcus luteus has been identified to metabolize benzo[a]pyrene and the most likely enzyme involved was DszA/NtaA-like oxygennase (27,39). ...
Article
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The participation of microbiota in myriads of physiological, metabolic, genetic and immunological processes shows that they are a fundamental part of human existence and health maintenance. The efficiency of drugs' absorption depends on solubility, stability, permeability and metabolic enzymes produced by the body and gut microbiota. Two major types of microbiota-drug interaction have been identified; direct and indirect. The use of antibiotics is a direct means of targeting intestinal microbes and short-term use of antibiotic can significantly alter the microbiome composition. It is noteworthy that not every microbial drug metabolism is of benefit to the host as some drugs can shut down microbial processes as observed in the co-administration of antiviral sorivudine with fluoropyridimide resulting in a toxic buildup of fluoropyridimide metabolites from blockade of host fluoropyridimide by the microbial-sorivudine metabolite. It has been reported that many classes of drugs and xenobiotics modify the gut microbiome composition which may be detrimental to human health. Microbiome-drug interaction may be beneficial or detrimental resulting in either treatment success or failure which is largely dependent on factors such as microbial enzymes, chemical composition of candidate drug, host immunity and the complex relationship that exists with the microbiome. The effects of microbiota on pharmacology of drugs and vice versa are discussed in this review. Abstrait: La participation du microbiote à des myriades de processus physiologiques, métaboliques, génétiques et immunologiques montre qu'ils sont un élément fondamental de l'existence et du maintien de la santé de l'être humain. L'efficacité de l'absorption des médicaments dépend de la solubilité, de la stabilité, de la perméabilité et des enzymes métaboliques produites par le corps et le microbiote intestinal. Deux types principaux d'interaction microbiote-médicament ont été identifiés; direct et indirect. L'utilisation d'antibiotiques est un moyen direct de cibler les microbes intestinaux et une utilisation à court terme d'antibiotique peut modifier de manière significative la composition du microbiome. Il est à noter que tous les métabolismes de médicaments microbiens ne sont pas bénéfiques pour l'hôte, car certains médicaments peuvent arrêter les processus microbiens observés lors de l'administration concomitante d'antiviral sorivudine et de fluoropyridimide, ce qui entraîne une accumulation toxique de métabolites de fluoropyridimide résultant du blocage du fluoropyridimide par l'hôte. métabolite microbien-sorivudine. Il a été rapporté que de nombreuses classes de médicaments et de xénobiotiques modifiaient la composition du microbiome intestinal, ce qui pourrait nuire à la santé humaine. Une interaction médicamenteuse-microbiome peut être bénéfique ou préjudiciable, entraînant le succès ou l'échec du traitement, 78 Microbiome-drug and xenobiotic interactions Afr. J. Clin. Exper. Microbiol. 2020; 21 (2): 78-87 qui dépend en grande partie de facteurs tels que les enzymes microbiennes, la composition chimique du médicament candidat, l'immunité de l'hôte et la relation complexe qui existe avec le microbiome. Les effets du microbiote sur la pharmacologie des médicaments et inversement sont discutés dans cette revue.
... In parallel to these advances stemming from metagenomics, more and more evidence is piling up supporting the key role of gut microbiota in xenometabolism (Sousa et al. 2008;Clayton et al. 2009;Zheng et al. 2013). In particular, metabolomics has made it possible to trace the metabolic fate of xenobiotic compounds (Segata et al. 2013;Wikoff & Anfora 2009; van Duynhoven et al. 2011), which, together with metagenomics, is leading to the recent resurge in the research on xenometabolism (Sowada et al. 2014;Johnson et al. 2012;Wilson & Nicholson 2016). ...
Thesis
Studies as early as in the 70s showed that the gut and its intrinsic gut microbiota is a possible site of drug modification and later studies confirmed that human microbiota metabolism with its diverse set of genes can be a cause for drug side effects. Yet, our knowledge of the biochemical capabilities of gut bacteria to interact with or metabolize therapeutic drugs remains largely incomplete. To our knowledge, there has not been any systematic screen of xenobiotic-microbial interactions elucidating how wide-spread bacterial drug modification is across therapeutic drugs or the gut microbiota. In my PhD work, I tested, under anaerobic conditions, 450 bacteria-drug interactions covering 25 metabolically diverse gut bacteria and 18 structurally diverse FDA-approved drugs. This revealed almost 50 novel bioaccumulation or biotransformation links between 19 bacterial species and 10 drugs. The implicated bacteria are phylogenetically diverse, including commensals, probiotics and bacteria associated with diseases. The affected drugs span diverse indication areas, from asthma (montelukast) to depression (duloxetine and aripiprazole). As a case in point, the results from this bacteria-drug interaction study are followed upon in more details through investigation of interactions involving duloxetine – a widely used antidepressant. I found that duloxetine induces higher diversity in synthetic bacterial communities, and its bioaccumulation by community members affects the community dynamics. Following, I found that duloxetine affects the native metabolism of B. uniformis and C. saccharolyticum, in particular the purine metabolism. These interactions might in turn influence bacterial behavior in a community. To find the direct protein targets of duloxetine in C. saccharolyticum, I used click chemistry-based methods and proteomics. Two of the five strongly enriched binding proteins are part of a NADH:quinone dehydrogenase complex. Two potential underlying mechanisms for duloxetine interactions are suggested: i) Duloxetine inhibits NADH:quinone dehydrogenase by binding to its quinone binding site. The resulting NADH excess leads to a change in downstream pathways like purine metabolism. ii) Duloxetine binds competitively on the NADH binding site of NADH:quinone dehydrogenase and other proteins. In addition to discovering new xenobiotic interactions, the study highlights a new dimension to gut microbiota-drug interactions, namely bioaccumulation, which so far has been largely overlooked. My results suggest that bioaccumulation of drug compounds might be a common feature to many gut bacteria and thus have broad and far-reaching implications for drug dosage decisions and personalized medicine.
... In a German study, 21 bacterial strains, isolated from the volar forearm and the neck of 11 subjects, could use B[a]P as their only carbon source. 71 Four isolates were found to completely degrade B[a]P, possibly preventing dermal B[a]P uptake, while partial B[a]P degradation might generate toxic metabolites. Moreover, He et al. 44 observed that the skin microflora of the forearm of 20 women was almost halved after exposure to atmospheric-equivalent O 3 levels for 2 h. ...
Article
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Indoor and outdoor airborne pollutants modify our environment and represent a growing threat to human health worldwide. Airborne pollution effects on respiratory and cardiac health and diseases have been well established, but its impact on skin remains poorly described. Nonetheless, the skin is one of the main targets of pollutants, which reach the superficial and deeper skin layers by transcutaneous and systemic routes. In this review, we report the outcomes of basic and clinical research studies monitoring pollutant levels in human tissues including the skin and hair. We present a current understanding of the biochemical and biophysical effects of pollutants on skin metabolism, inflammatory processes and oxidative stress, with a focus on polyaromatic hydrocarbons and ground‐level ozone that are widespread outdoor pollutants whose effects are mostly studied. We reviewed the literature to report the clinical effects of pollutants on skin health and skin aging and their impact on some chronic inflammatory skin diseases. We also discuss the potential interactions of airborne pollutants with either ultraviolet radiation, or human skin microbiota and their specific impact on skin health. This article is protected by copyright. All rights reserved.
... 67 PAH degrading microbes have also been observed on human skin. 68 In addition, gut microbes have also been associated with breakdown and reactivation of a variety of drugs including the cardiovascular drug, digoxin and the cancer drug, irinotecan. 69 ...
Article
For much of our history, the most basic information about the microbial world has evaded characterization. Next-generation sequencing has led to a rapid increase in understanding of the structure and function of host-associated microbial communities in diverse diseases ranging from obesity to autism. Through experimental systems such as gnotobiotic mice only colonized with known microbes, a causal relationship between microbial communities and disease phenotypes has been supported. Now microbiome research must move beyond correlations and general demonstration of causality to develop mechanistic understandings of microbial influence, including through their metabolic activities. Similar to the microbiome field, advances in technologies for cataloguing small molecules have broadened our understanding of the metabolites that populate our bodies. Integration of microbial and metabolomics data paired with experimental validation has promise for identifying microbial influence on host physiology through production, modification or degradation of bioactive metabolites. Realization of microbial metabolic activities that affect health is hampered by gaps in our understanding of 1) biological properties of microbes and metabolites, 2) which microbial enzymes/pathways produce which metabolites and 3) the effects of metabolites on hosts. Capitalizing upon known mechanistic relationships and filling gaps in our understanding has the potential to enable translational microbiome research across disease contexts.
... Cigarette smoke is another source of pollution stressors known to affect skin health (24). Certain bacteria of skin origin were reported to display a metabolic capacity to break down organic pollutants, like benzo(a)pyrene, that exist in both cigarette smoke and automobile exhaust fumes (25), suggesting a potential combinatorial effect of regional air pollution and a smoking lifestyle on the skin microbiome. Indeed, our MNI results indicated that Shanghai smokers (SS) had the least robust microbiome network compared with Chongming nonsmokers (CN). ...
Article
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Urban living has been reported to cause various skin disorders. As an integral part of the skin barrier, the skin microbiome is among the key factors associated with urbanization-related skin alterations. The role of skin microbiome in mediating the effect of urban stressors (e.g., air pollutants) on skin physiology is not well understood. We generated 16S sequencing data and constructed a microbiome network of individual (MNI) to analyze the effect of pollution stressors on the microbiome network and its downstream mediation effect on skin physiology in a personalized manner. In particular, we found that the connectivity and fragility of MNIs significantly mediated the adverse effects of air pollution on skin health, and a smoking lifestyle deepened the negative effects of pollution stress on facial skin microbiota. This is the first study that describes the mediation effect of the microbiome network on the skin's physiological response toward environmental factors as revealed by our newly developed MNI approach and conditional process analysis. IMPORTANCE The association between the skin microbiome and skin health has been widely reported. However, the role of the skin microbiome in mediating skin physiology remains a challenging and yet priority subject in the field. Through developing a novel MNI method followed by mediation analysis, we characterized the network signature of the skin microbiome at an individual level and revealed the role of the skin microbiome in mediating the skin's responses toward environmental stressors. Our findings may shed new light on microbiome functions in skin health and lay the foundation for the design of a microbiome-based intervention strategy in the future.
... Some of these species were investigated for the presence of catabolic genes/enzymes such as dehydrogenase, monooxygenase, catechol dioxygense, and aromatic-ring-hydroxylating dioxygenase in different studies. 12,14,29,30 Phylogenetic tree for analysis of evolutionary relationship of K. flava DTU-1Y with these identified 18 different bacterial species was constructed 13 NM, not mentioned; seq., sequence. ( Figure 1). ...
Article
Polycyclic aromatic hydrocarbons (PAHs) are persistent organic pollutants, ubiquitously present and are hazardous to all forms of life due to their toxic, carcinogenic, and mutagenic nature. With enhanced understanding of adverse effects of PAHs on living organisms, reclamation of PAH-contaminated sites has become a global concern. In order to devise efficient bioremediation strategies for PAH-degradation, the identification and study of metabolic potential of microbial species is essential. The goal of this study is to isolate PAH-degrading bacterial strains from petroleum contaminated soil that can utilize PAHs as their sole carbon source and investigate their growth on medium containing PAHs as only carbon source. For the first time, the evolutionary relationship of isolated bacterial strains with known PAH-degrading bacterial strains having PAH-catabolic genes/enzymes involved in PAH-bioremediation was examined. Two strains isolated from contaminated soil, that is, Kocuria flava DTU-1Y and Rhodococcus pyridinivorans DTU-7P may have the ability to utilize PAHs as sole carbon source for their growth. Phylogenetic analysis for evolutionary relationship revealed that these strains are related to different known PAH-degrading bacterial strains which have catabolic genes/enzymes involved in degradation pathway. The bacterial strains reported in this study may also possess the genes responsible for PAH-degradation and can prove useful in devising sustainable bioremediation approach.
... This enrichment was carried out in microplates in 200 µL, unlike the aforementioned studies, which were generally carried out in bigger volumes, equal or more than 50 mL. Twenty one species of BaP degrading bacteria were identified, and these belong to various genera, including Micrococcus, Bacillus, Pseudomonas and Staphylococcus, [48] (ST27). However, in this study, the BaP was dissolved in dimethyl sulfoxide (DMSO) during the enrichment procedures. ...
Preprint
Polycyclic aromatic hydrocarbons (PAHs), which consist of low-molecular-weight PAHs (LMW-PAHs) and high-molecular-weight PAHs (HMW-PAHs), form an important class of pollutants. Pyrene and benzo[a]pyrene (BaP) are the main pollutants belonging to HMW-PAHs, and their degradation by microorganisms remains an important strategy for their removal from the environments. Extensive studies have been carried out on the isolation and characterisation of microorganisms that actively degrade LMW-PAHs, and to a certain extent, the HMW-PAH pyrene. However, so far, limited work has been carried out on BaP biodegradation. BaP consists of five fused aromatic rings, which confers this compound a high stability, rendering it less amenable to biodegradation. The current review summarizes the emerging reports on BaP biodegradation. More specifically, work carried out on BaP bacterial degradation and current knowledge gaps that limit our understanding of BaP degradation are highlighted. Moreover, new avenues of research on BaP degradation are proposed, specifically in the context of the development of “omics” approaches
... This enrichment was carried out in microplates in 200 µL, unlike the aforementioned studies, which were generally carried out in bigger volumes, equal or more than 50 mL. Twenty one species of BaP degrading bacteria were identified, and these belong to various genera, including Micrococcus, Bacillus, Pseudomonas and Staphylococcus, [48] (ST27). However, in this study, the BaP was dissolved in dimethyl sulfoxide (DMSO) during the enrichment procedures. ...
Article
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Benzo[a]pyrene (BaP) is one the main pollutants belonging to the high-molecular-weight PAHs (HMW-PAHs) class and its degradation by microorganisms remains an important strategy for its removal from the environment. Extensive studies have been carried out on the isolation and characterisation of microorganisms that can actively degrade low-molecular-weight PAHs (LMW-PAHs), and to a certain extent, the HMW-PAH pyrene. However, so far, limited work has been carried out on BaP biodegradation. BaP consists of five fused aromatic rings, which confers this compound a high chemical stability, rendering it less amenable to biodegradation. The current review summarizes the emerging reports on BaP biodegradation. More specifically, work carried out on BaP bacterial degradation and current knowledge gaps that limit our understanding of BaP degradation are highlighted. Moreover, new avenues of research on BaP degradation are proposed, specifically in the context of the development of “omics” approaches.
... Increases in abundances of bacteria in the family Moraxellaceae, which contains several opportunistic pathogens (Austin and Austin, 2016), is associated with increased stress in fish (Boutin et al., 2013). Furthermore, these same taxa are capable of degrading BaP when isolated from human skin (Sowada et al., 2014). Although the taxa were not the same, a similar phenomenon of enrichment of taxa associated with hydrocarbon degradation was seen in (DeBofsky et al, (2020a)). ...
Article
The microbiome has been described as an additional host “organ” with well-established beneficial roles. However, the effects of exposures to chemicals on both structure and function of the gut microbiome of fishes are understudied. To determine effects of benzo[a]pyrene (BaP), a model persistent organic pollutant, on structural shifts of gut microbiome in juvenile fathead minnows (Pimephales promelas), fish were exposed ad libitum in the diet to concentrations of 1, 10, 100, or 1,000 μg BaP g⁻¹ food, in addition to a vehicle control, for two weeks. To determine the link between exposure to BaP and changes in the microbial community, concentrations of metabolites of BaP were measured in fish bile and 16S rRNA amplicon sequencing was used to evaluate the microbiome. Exposure to BaP only reduced alpha-diversity at the greatest exposure concentrations. However, it did alter community composition assessed as differential abundance of taxa and reduced network complexity of the microbial community in all exposure groups. Results presented here illustrate that environmentally-relevant concentrations of BaP can alter the diversity of the gut microbiome and community network connectivity.
... ATCC 17483, Pseudomonas putida PpG7, Pseudomonas putida, Pseudomonas aeruginosa, Pelomonas saccharophila (classified as Pseudomonas saccharophila before year 2005), Pseudomonas fluorescens, Pseudomonas sp., MTCC 2445, and Pseudomonas sp. JP1 (Aitken et al. 1998;Barnsley 1975;Guntupalli et al. 2016;Liang et al. 2014;Luo et al. 2009;Mishra and Singh 2014;Sowada et al. 2014;Trzesicka-Mlynarz and Ward 1995). Among them, one facultative anaerobe Pseudomonas sp. ...
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Purpose Polybrominated diphenyl ethers (PBDEs) and polycyclic aromatic hydrocarbons are common contaminants in soils. In PBDEs, decabromodiphenyl ether (BDE-209) is the most persistent, while benzo(a)pyrene (BaP) is an identified human carcinogen. This study is aimed to solve the contamination of BDE-209 and BaP in soils by adjusting environmental variables and amendments of microorganisms or nutrients. Methods A batch test and a sandbox test were performed. In the batch test on an artificial soil, the Taguchi method was applied to define optimum environmental factors. The sandbox test was conducted to verify if addition of soybean soil nanoemulsion (SONE) or acclimated microorganisms can assist the bioremediation of BDE-209 and BaP in rice-paddy soil under optimum volumetric water content (θW). Next-generation sequencing (NGS) was performed to observe the microbial profile, correlation, and interaction. Results The batch test revealed that the θW is the predominant factor for both contaminants. In the sandbox test, bioaugmentation with SONE-amended group achieved 55% and 74% removals in 70 days for fresh BDE-209 and BaP, respectively. Yet for weathered BDE-209, natural attenuation group was the best with about 75% removal in 70 days. NGS data showed that a few dominant genera formed a strong alliance against a large group of others. Conclusions The results suggest that the θW is the key parameter and proper amendment of soil organic matter, and SONE can enhance the bioremediation. The results implied that natural attenuation with water flooding could be effective for the soils historically contaminated by BDE-209.
... This has been recently reviewed by Ostrem Loss and Yu (Ostrem Loss and Yu 2018). Research regarding benzo[a]pyrene metabolism by the human gut microbiota is lacking, with one report on bacterial isolates from the human skin microbiota found to degrade benzo[a]pyrene (Sowada et al. 2014). Unfortunately, these metabolites were found cytotoxic and genotoxic; therefore, it is critical to consider this metabolic pathway harbored by the human microbiota that could complicate how we perceive benzo[a]pyrene's toxicity (Sowada et al. 2017). ...
Article
Food contaminants represent food constituents that are accidentally introduced during food preparation cycle. In addition to their direct toxic effects on human health at different levels, they influence both gut microbiota composition and function. This often leads to metabolic disorders linked to many aspects of the human body. Foods are poisoned with physical, chemical, or biological factors either in agriculture or during processing steps. These include naturally occurring compounds such as mycotoxins, agricultural chemicals such as pesticides and antibiotics, persistent organic pollutants, thermal process contaminants (e.g., furans, aromatic compounds, and nitrosamines), or heavy metals. These xenobiotics cause a wide range of toxicities. They also disturb gut homeostasis by inducing intestinal damage and inflammation and gut microbiota dysbio-sis. We present herein the first comprehensive review of how food contaminants can specifically influence gut microbiota and intestinal homeostasis, and likewise via gut microbiota-mediated contaminants metabolism. The first part summarizes the different classes of food contaminants and their impact on gut microbiota and its homeostasis, while, the second part discusses the promising role of the gut microbiota in the biodegradation of these xenobiotics and the possible unfortunate exaggerated toxicities in some cases. Finally, we summarize the novel strategies to minimize toxic effects of food contaminants and future directions needed to explore the interactions between food contaminants and the gut microbiota.
Chapter
Rapid industrialization has led to the generation of large number of pollutants that are dumped into the environment posing serious health concerns. Bioremediation is a reliable and eco‐friendly technique that utilizes diverse metabolic activitises of microorganisms to transform a broad range of pollutants into harmless products. The energy and carbon produced during the metabolism of pollutants are utilized by the microbes for their growth. A wide range of microorganisms with degradation potential have been isolated and characterized from different sites of contamination. Microbes carry genes for diverse metabolic processes such as oxidation, immobilization, transformation, or nitration for degradation of different types of pollutants. Complete degradation of the compounds depends on the interaction between the microbes, substrates, and the environmental conditions. Considering the increase in production of waste, current research aims to integrate the multi‐omics and system biology approaches to generate recombinant strains of microbes in order to expedite the process of bioremediation.
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Driven by the fast paced development of complex test systems in vitro, mass spectrometry and omics we finally have the tools to unravel the molecular events that underlie toxicological adversity. Yet, timely regulatory adaptation of these new tools continues to pose major challenges even for organs readily accessible such as skin. The reasons for this encompass a need for conservatism as well as the need of tests to serve an existing regulatory framework rather than to produce scientific knowledge. It is important to be aware of this in order to align regulatory skin toxicity with the 3R‐principles more readily. While most chemical safety testing is still based on animal data regulatory frameworks have seen a strong push towards non‐animal approaches. The endpoints corrosion, irritation, sensitisation, absorption, and phototoxicity, for example, can now be covered in vitro with the corresponding test guidelines (TGs) being made available by the OECD. However, in vitro approaches tend to be more reductionist. Hence, a combination of several tests is usually preferable in order to achieve satisfying predictivity. Moreover, the test systems as well as their combined use needs to be standardised and is therefore subject not only to validation but to the ongoing development of so‐called integrated approaches to testing and assessment (IATAs). Concomitantly, skin models are being refined to deliver the complexity required for increased applicability and predictivity. Given the importance of regulatory applicability for 3R‐derived approaches to have a long lasting impact this review examines the state of regulatory implementation and perspectives, respectively. This article is protected by copyright. All rights reserved.
Article
The skin plays an important role in human health by providing barrier protection against environmental stressors. In addition to human skin cells, the cutaneous barrier is also home to a network of organisms that have co‐evolved with humans, referred to as the cutaneous microbiome. This network has been demonstrated to play an active role in skin health and the manifestation of cutaneous disease. Here, we review how a warming world and its attendant changes in climatic variables, including temperature, humidity, ultraviolet radiation, and air pollution, influence the cutaneous microbiome and, in turn, skin health. Studies indicate that the cutaneous microbiome is affected by these factors, and these changes may influence the epidemiology and severity of cutaneous disorders including atopic dermatitis, acne vulgaris, psoriasis, and skin cancer. Further investigation into how the cutaneous microbiome changes in response to climate change and subsequently influences skin disease is needed to better anticipate future dermatologic needs and potentially generate novel therapeutic solutions in response.
Chapter
Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous pollutants that are harmful products of incomplete combustion of organic matter. PAH and their derivatives possess toxic, carcinogenic, and mutagenic effects in nearly all living organisms, which are further enhanced due to bioaccumulation and biomagnification. Thus, their detrimental effects generated the need for their mitigation in a sustainable manner. Among various remediation strategies, microbial remediation is increasingly gaining interest as economically justified and effective cleanup approach, because many microbial species use PAH as their energy source. These microbes possess various PAH degrading genes such as ndoB, nidA, pdoB, nahAc, and cytochrome P450, which also make them perfect tools for genetic engineering. Bacterial species such as Pseudomonas, Comamonas, Mycobacterium, Rhodococcus, and Sphingomonas may aerobically or anaerobically use various metabolic pathways to degrade PAH. Both ligninolytic and non‐ligninolytic fungi are well known for either co‐metabolizing or completely metabolizing PAH. Moreover, some algal and microalgal species such as Scenedesmus acutus, Selanastum capricornutum, and Ankistrodesmus braunii have the ability to either transform or co‐metabolize PAH. Microbial remediation depends on various factors such as microbial activity, bioavailability of PAH, and environmental factors such as pH, temperature, nutrients, oxygen, and humidity. We review the remediation strategies of PAH through diverse degradation pathways by various bacterial, fungal, and algal species. Moreover, we provide an insight of genes and enzymes involved in these processes in order to explore genetic engineering approaches for effective and sustainable degradation of PAH.
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The microbiome, as a community of microorganisms and their structural elements, genomes, metabolites/signal molecules, has been shown to play an important role in human health, with significant beneficial applications for gut health. Skin microbiome has emerged as a new field with high potential to develop disruptive solutions to manage skin health and disease. Despite an incomplete toolbox for skin microbiome analyses, much progress has been made towards functional dissection of microbiomes and host-microbiome interactions. A standardized and robust investigation of the skin microbiome is necessary to provide accurate microbial information and set the base for a successful translation of innovations in the dermo-cosmetic field. This review provides an overview of how the landscape of skin microbiome research has evolved from method development (multi-omics/data-based analytical approaches) to the discovery and development of novel microbiome-derived ingredients. Moreover, it provides a summary of the latest findings on interactions between the microbiomes (gut and skin) and skin health/disease. Solutions derived from these two paths are used to develop novel microbiome-based ingredients or solutions acting on skin homeostasis are proposed. The most promising skin and gut-derived microbiome interventional strategies are presented, along with regulatory, safety, industrial, and technical challenges related to a successful translation of these microbiome-based concepts/technologies in the dermo-cosmetic industry.
Thesis
La dermatite de contact allergique (DCA) est une réaction exacerbée du système immunitaire cutané vis-à-vis d’un allergène de contact. La prévalence de la DCA étant de 20 % au sein de la population mondiale, il est important d’identifier les composés allergisants. Différentes réglementations européennes, telles que le règlement REACh ou la directive cosmétique, interdisent l’utilisation de test sur l’animal. C’est dans ce contexte que différentes méthodes alternatives ont été développées pour évaluer la sensibilisation cutanée. La stratégie actuelle d’évaluation du potentiel sensibilisant consiste à réaliser un ensemble de tests alternatifs, chacun mimant un évènement clé du mécanisme : l’hapténisation, l’activation des kératinocytes ou des cellules dendritiques.Cependant, ces tests utilisent principalement des monocultures et ne prennent donc pas en compte les interactions cellulaires qui peuvent avoir lieu in vivo. De plus, les évaluations de la pénétration et du métabolisme cutanés sont négligées dans les tests développés.Afin de mimer la fine orchestration des événements intervenant lors de la sensibilisation cutanée, nous proposons un modèle d’épiderme humain reconstruit (RhE) co-cultivé avec la lignée cellulaire THP-1, servant de substitut aux cellules dendritiques. Nous avons caractérisé, et étudié la pertinence de ce modèle à l’aide de molécules chimiques de référence. Ce travail a permis l’identification de biomarqueurs, tels que CD54, IL-8 et CCL3, spécifiques à l’évaluation in vitro de la sensibilisation cutanée des xénobiotiques.
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Chapter
Polycyclic aromatic hydrocarbons (PAHs) are widespread persistent contaminants that enter the environment from both natural and anthropogenic sources. The principal role of PAHs in environmental degradation is played by biological systems. The most important among these are plants and microorganisms, which have a flexible metabolism and unique mechanisms of pollutant detoxification. This review discusses the uptake, translocation, accumulation, and biochemical transformation of PAHs in plants, PAH effects on rhizosphere microbial communities, and pathways for the microbial degradation of these compounds. Special attention is given to plant growth promoting rhizobacteria, which are closely associated with plants, and to plant microbial cooperation for the biodegradation of PAHs. The review concludes with a discussion of the microbe-assisted phytoremediation of PAHs.
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Benzo[a]pyrene (BaP) is a model compound of polycyclic aromatic hydrocarbons. The relationship between its toxicity and some target biomolecules has been investigated. To reveal the interactions of BaP biodegradation and metabolic network, BaP intermediates, proteome, carbon metabolism and ion transport were analyzed. The results show that 76% BaP was degraded by Brevibacillus brevis within 7 d through the cleavage of aromatic rings with the production of 1-naphthol and 2-naphthol. During this process, the expression of xylose isomerase was induced for xylose metabolism, whereas, α-cyclodextrin could no longer be metabolized. Lactic acid, acetic acid and oxalic acid at 0.1–1.2 mg dm⁻³ were released stemming from their enhanced biosynthesis in the pathways of pyruvate metabolism and citrate cycle, while 5–7 mg dm⁻³ of PO4³⁻ were transported for energy metabolism. The relative abundance of 43 proteins was significantly increased for pyruvate metabolism, citrate cycle, amino acid metabolism, purine metabolism, ribosome metabolism and protein synthesis.
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Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous in the environment. They are highly toxigenic and carcinogenic. Probiotic bacteria isolated from fermented foods were tested to check their ability to degrade and/or detoxify PAHs. Five probiotic bacteria with distinct morphologies were isolated from a mixture of 26 fermented foods co-cultured with benzo(a)pyrene (BaP) containing Bushnell Haas minimal broth. Among them, B. velezensis (PMC10) significantly reduced the abundance of BaP in the broth. PMC10 completely degraded BaP presented at a lower concentration in broth culture. B. velezensis also showed a clear zone of degradation on BaP coated Bushnell Haas agar plate. Gene expression profiling showed significant increases of PAH-ring hydroxylating dioxygenases and 4-hydroxybenzoate 3-monooxygenase genes in B. velezensis in response to BaP treatment. Besides, both live and heat-killed B. velezensis removed BaP and naphthalene (Nap) from phosphate buffer solution. Live B. velezensis did not show any cytotoxicity to macrophage or human dermal fibroblast cells. Live-cell and cell-free supernatant of B. velezensis showed potential anti-inflammatory effects. Cell-free supernatant and extract of B. velezensis also showed free radical scavenging effects. These results highlight the prospective of B. velezensis for the biodegradation and removal of toxic PAHs from the human body. The biodegradation of BaP might be regulated by ring-hydroxylating dioxygenase initiated metabolic pathway.
Chapter
The skin is our frontier with the exterior environment and is naturally exposed of an innumerous variety of chemical, physical and biological agents, which complete set is named as exposome. The relation of the exposome with the microbial community of the skin is a new field of interest of the science. This article aim to present a review of the scientific knowledge published in the literature about the relation of the two major skin exposome agents, solar radiation and pollution, and the skin microbiome.
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The chapter gave an insight into the biodegradation roles of microbes existing within the extreme environment of polycyclic aromatic hydrocarbon - degraded sites.
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