Rafał Szewczyk

LabExperts sp. z o.o.

Alachlor is an herbicide that is widely used worldwide to protect plant crops against broadleaf weeds and annual grasses. However, due to its endocrine-disrupting activity, its application had been banned in the European Union. As described in our earlier work, Paecilomyces marquandii is a microscopic fungus capable of alachlor removal by N-acetyl...

4-n-nonylphenol (4-n-NP) is an endocrine disrupting compound (EDC); pollutants that cause serious disturbances in the environment. This study shows the degradation pathway and initial proteome analysis in cultures of a fungus that actively degrades 4-n-NP, Metarhizium robertsii. The research revealed the presence of 14 4-n-NP metabolites formed as...

Alachlor, a popular chloroacetanilide herbicide, can be a potential health risk factor. Soil microorganisms are primarily responsible for conversion and migration of alachlor in natural environment, but knowledge concerning alachlor biodegradation is not complete. Therefore, we studied the ability of Paecilomyces marquandii, soil fungus tolerant to...

Mycolic acids (MAs), which play a crucial role in the architecture of mycobacterial cell walls, were analyzed using electrospray ionization tandem mass spectrometry. A targeted analysis based on the 10 most abundant and characteristic multiple reaction monitoring pairs was used to profile the crude fatty acid mixtures from Mtb and several nontuberc...

4-Nonylphenols (NPs) are endocrine disrupting compounds (EDCs) which are known to interfere with the endocrine system of humans and animals. The aim of this study was to test the ability of non-ligninolytic filamentous fungus Gliocephalotrichum simplex to biodegrade 4-n-NP. The results revealed that during the first 24h of incubation, 4-n-NP at the...

We have previously shown that 2-thiouridine (S2U), either as a single nucleoside or as an element of RNA chain, is effectively desulfurized under applied in vitro oxidative conditions. The chemically induced desulfuration of S2U resulted in two products: 4-pyrimidinone nucleoside (H2U) and uridine (U). Recently, we investigated whether the desulfur...

We have previously shown that 2-thiouridine (S2U), either as a single nucleoside or as an element of RNA chain, is effectively desulfurized under applied in vitro oxidative conditions. Chemically induced desulfuration of S2U resulted in two products: 4-pyrimidinone nucleoside (H2U) and uridine (U). Recently, we investigated whether desulfuration of...

Profound tuberculosis (TB)-induced metabolic changes reflected in the blood metabolomic profile may provide an opportunity to identify specific markers of Mycobacterium tuberculosis infection. Using targeted liquid chromatography tandem mass spectrometry, we compared the levels of 30 small metabolites, including amino acids and derivatives, and sma...

Keratin is important and needed for the growth of dermatophytes in the host tissue. In turn, the ability to invade keratinised tissues is defined as a pivotal virulence attribute of this group of medically important fungi. The host–dermatophyte interaction is accompanied by an adaptation of fungal metabolism that allows them to adhere to the host t...

Atrazine, is one of major concern pesticides contaminating agricultural areas and ground water. Its microbial biodegradation seems to be the most efficient in terms of economic and environmental benefits. In the present work the cometabolic biodegradation of atrazine by the fungus Metarhizum robertsii IM 6519 during 10-day batch cultures was charac...

A proteomic study of Cunninghamella echinulata recovery during exposure to tributyltin was conducted with 2-D SDS-PAGE protein separation and profiling, MALDI-TOF/TOF protein identification, and PCA analysis. The presence of TBT resulted in an upregulation of enzymes related to energy production via cellular respiration. The unique overexpression o...

Background: Determining the etiology and possible treatment strategies for numerous diseases requires a comprehensive understanding of compensatory mechanisms in physiological systems. The vagus nerve acts as a key interface between the brain and the peripheral internal organs. We set out to identify mechanisms compensating for a lack of neuronal...

The study reports the response to herbicide of the 2,4-dichlorophenoxyacetic acid (2,4-D)–degrading fungal strain Umbelopsis isabellina. A comparative analysis covered 41 free amino acids as well as 140 lipid species of fatty acids, phospholipids, acylglycerols, sphingolipids, and sterols. 2,4-D presence led to a decrease in fungal catalase activit...

Multiple reaction monitoring (MRM) transitions for phospholipids identified in U. isabellina. (PDF)

ROS (measured with H2DCFDA) generated in U. isabelina cells incubated with 2,4-D at 24h (a) of incubation in comparison to 24h (b) controls without toxic compound. (DOCX)

Hypothetical representation of the lipid metabolism in U. isabellina. (PDF)

MS/MS spectra of selected lipids. (PDF)

A detailed description of the materials and methods used in this study. (PDF)

Multiple reaction monitoring (MRM) transitions for triacylglycerols (TAGs) identified in U. isabellina. (PDF)

The exposure of microorganisms to toxic compounds induces a range of responses at different levels of the cell morphology, biochemistry and physiology. Tributyltin (TBT) is a highly toxic compound used for many years in industry as a marine anti-fouling agent or as a biocide in preservatives of wood. We previously described a microscopic filamentou...

Ametryn is a representative of a class of s-triazine herbicides absorbed by plant roots and leaves and characterized as a photosynthesis inhibitor. It is still in use in some countries in the farming of pineapples, soybean, corn, cotton, sugar cane or bananas; however, due to the adverse effects of s-triazine herbicides on living organisms use of t...

Ametryn is a representative of a class of s-triazine herbicides absorbed by plant roots and leaves and characterized as a photosynthesis inhibitor. It is still in use in some countries in the farming of pineapples, soybean, corn, cotton, sugar cane or bananas; however, due to the adverse effects of s-triazine herbicides on living organisms use of t...

The 5-substituted 2-thiouridines (R5S2U) present in the first (wobble) position of the anticodons of transfer RNAs (tRNAs) contribute to accuracy in reading mRNA codons and tune protein synthesis. Previously, we have shown that, under oxidative stress conditions in vitro, R5S2Us are sensitive to hydrogen peroxide (H2O2), and their oxidative desulfu...

We examined the structural and functional consequences of oxidative modification of C-reactive protein (CRP) by hypochlorous acid (HOCl), which can be generated in vivo via the myeloperoxidase/H2O2/Cl⁻ system. HOCl exposure resulted in the oxidation and chlorination of CRP amino acid residues, leading to protein unfolding, greater surface hydrophob...

Proteomics has become an important part of the characterization of biological systems or single organisms. In this chapter, background relating to proteomics studies including definitions, instrumentation, and basic as well as more complex workflows for protein extraction and identification with different instrumental techniques and bioinformatics...

Metabolic pathways in living organisms are series of chemical reactions and typically consist of the enzymatic activities of intra- or extracellular enzymes. This chapter focuses on the metabolomic workflow characterization, which may be briefly characterised as the initial discovery, profiling, and final quantitation of the compound or a class of...

Reactive oxygen species (ROS) have a negative influence on the structure and metabolism of the living cells. Nucleic acids, proteins and lipids are the ones of the most sensitive compounds, that is why the evolution of organisms led to the development of numerous enzymatic and non-enzymatic antioxidant strategies. Majority of self-defense mechanism...

Microorganisms play an important role in the elimination of harmful pollutants from the environment. For several years investigations of biodegradation processes have been focused mainly on determining the degradation products of xenobiotics. In the last decade, more and more attention has been paid to the knowledge of the molecular basis of metabo...

Anomalies in environmental conditions, such as dangerous pollutants, activate a series of processes in microbial cells that allow them to minimise the negative impact of the environmental stress. Since membranes constitute the main target for the action of toxic compounds, most adaptive mechanisms are concerned with maintenance of the membrane flui...

Melatonin (N-acetyl-5-methoxytryptamine) has a great potential for plant biostimulation. Its role in plant physiology is intensively explored, and its important function in plant stress defence frequently underlined. Melatonin is particularly effective when applied as an additional factor of seed priming. In the presented research, hydroconditionin...

Mycobacteria are able to degrade natural sterols and use them as a source of carbon and energy. Several genes which play an important role in cholesterol ring degradation have been described in Mycobacterium smegmatis. However, there are limited data describing the molecular mechanism of the aliphatic side chain degradation by Mycobacterium spp. In...

Background: 3-Bromopyruvic acid (3-BP), a glycolytic inhibitor and a promising anticancer compound, induces oxidative stress and depletes cells of glutathione (GSH). The causes of GSH loss remain unclear. The aim of this study was to ascertain whether 3-BP forms a conjugate with glutathione. Methods: GSH was incubated with various amounts of 3-B...

Melatonin (MEL; N-acetyl-5-methoxytryptamine) plays an important role in plant stress defense. Various plant species rich in this indoleamine have shown a higher capacity for stress tolerance. Moreover, it has great potential for plant biostimulation, is biodegradable and non-toxic for the environment. All this indicates that our concept of seed en...

Tributyltin (TBT) is one of the most deleterious compounds introduced into natural environment by humans. The ability of Cunninghamella echinulata to degrade tributyltin (TBT) (5 mg l−1) as well as the effect of the xenobiotic on fungal amino acids composition and proteins profile were examined. C. echinulata removed 91% of the initial biocide conc...

Nitroxides are promising compounds for prevention of undesired protein modifications. The aim of this study was to compare the efficiency of 11 nitroxides, derivatives of 2,2,6,6-tetramethylpiperidine-1-oxide (TEMPO) and 2,2,5,5-tetramethylpirrolidine-1-oxyl (PROXYL) in prevention of nitration and oxidation of model compounds and human serum albumi...

In this paper, an antimycobacterial component of extracellular metabolites of a gut bacterium Raoultella ornithinolytica from D. veneta earthworms was isolated and its antimycobacterial action was tested using Mycobacterium smegmatis. After incubation with the complex obtained, formation of pores and furrows in cell walls was observed using microsc...

The acceleration of alachlor degradation by Paecilomyces marquandii under controlled and optimized conditions of fungal cultivation in liquid batches was observed (by ca. 20% in comparison to the flask cultures). Acidic environment and oxygen limitation resulted in deterioration of herbicide elimination. Efficient xenobiotic degradation did not cor...

The efficiency of pre-sowing conditioning/priming methods used to apply melatonin into seeds was verified: osmopriming in the case of dicot Cucumis sativus and hydropriming of monocot Zea mays seeds. Both priming techniques were selected experimentally as optimal for the studied plant species. Four different seed variants were compared: control non...

AimsThe characterization of the antitumor activity and chemical identification of the compounds obtained after isolation extracellular metabolites of bacteria Raoultella ornithinolytica.Methods and ResultsThe fraction with anticancer activity against the HeLa cell line, T47D, and TOV-112D was obtained from supernatants of R. ornithinolytica culture...

The impact of melatonin (50 µM L−1) applied to Vigna radiata seeds by hydro-priming on phenolic content, L-phenylalanine ammonialyase (PAL) activity, MEL level, antioxidant properties of ethanol extracts as well as electrolyte leakage from chilled and re-warmed Vigna radiata roots of seedlings were examined. Seedlings obtained from non-primed seeds...

The subject of analysis is the male skeleton from a double burial of the Globular Amphora Culture, derived from the Neolithic site at Brześć Kujawski in Kujawy region (central Poland). Within the spine of the individual advanced lesions are observed (destruction of the vertebral bodies, symptoms of the periostitis in the thoracic region) which are...

To investigate the response of the tributyltin-degrading fungal strain Cunninghamella elegans to the organotin, a comparative lipidomics strategy was employed using an LC/MS-MS technique. A total of 49 lipid species were identified. Individual phospholipids were then quantified using a multiple reaction monitoring method. Tributyltin (TBT) caused a...

Exogenous melatonin (MEL) applied into seeds as a biostimulator improving seed vigour, germination and seedling growth

4-nonylophenol (4-NP) is a mixture of toxic degradation intermediates of non-ionic surfactants used worldwide, showing endocrine disrupting activity. Biodegradation of one of 4-NP isomers – 4-n-NP (non-branched isomer of 4-NP), was studied using the filamentous fungus Aspergillus versicolor IM 2161, which demonstrates high detoxification and minera...

Organotin compounds are ubiquitous in environment. However, biodegradation of tributyltin (TBT) and dibutyltin (DBT) to non toxic metabolites by fungi has been seldom observed. In this study we constructed a fungal co-culture with an efficient ability of TBT and its metabolites removal. The microscopic fungus strain Cunninghamella elegans degraded...

Mycolic acids are one of the basic elements of the cell wall structure of bacteria belonging to the suborder Corynebacterineae, constituting from 20% to 40% of dry weight. Additionally, they show high structural diversity within each family and species. Nowadays, profiles of mycolic acids are widely described for the genus Mycobacterium, the causat...

A process of dibutyl sulphide (DBS) electro-oxidation using electrolysis and cyclic voltamperometry was investigated in water-methanol solution using different electrodes (platinum, boron doped diamond, graphite and glassy carbon). Obtained results indicate that the DBS electro-oxidation process is irreversible in voltamperometric conditions. It wa...

Microbial ability vary when pollutants exist together in the environment in comparison to the presence of single toxic compound. The influence of alachlor and zinc on the growth of the filamentous fungus Paecilomyces marquandii and its ability to eliminate alachlor and zinc has been studied. Their simultaneous presence in the polluted environment i...

Pentachlorophenol (PCP) has been widely used for many years and belongs to the most toxic pollutants. Spent engine oils enter environment every day in many ways. Both of them cause great environmental concern. In the present work we focused on identifying metabolites of PCP biodegradation formed in the cultures of Mucor ramosissimus IM 6203 and opt...

Pentachlorophenol (PCP) is a toxic xenobiotic of great environmental concern. It has been widely used for many years as a bactericide, fungicide, defoliant, herbicide and wood preservative. In this article, PCP properties, microbial biodegradation and other approaches of this xenobiotic elimination from contaminated areas are reviewed.

The growth abilities of fifteen fungal strains isolated from contaminated areas, in the presence of xenobiotics compounds mixture (overworked cutting fluid, crude and waste oil) were examined. Strains with the richest growth were chosen for anthracene, phenanthrene and pentachlorophenol biodegradation in Sabouraud medium (with initial xenobiotic co...