Selma Leite

• Federal University of Rio de Janeiro

With the industrial and population advances, the generation of effluents containing heavy metals has grown a lot. In this work, the commercial biomass of the yeast Saccharomyces cerevisiae Perlage ® BB were carried out as Cu (II) ion biosorbent. The influence of some variables such as metal concentration, pH range, equilibrium time and biomass conc...

Coffee is one of the most consumed non-alcoholic beverages in the world. It is well known that some compounds present in coffee beans have important biological activities. In this study, evidence was turned to βN-alkanoyl-5-hydroxytryptamides (C-5HTs) and to the furokaurane diterpenes cafestol and kahweol, associated with gastric irritation and inc...

Nanotechnology and biotechnology are branches of science that have been evolving quickly. The interaction between nanotechnology and biotechnology have influenced the creation of a research field in constant development identified as Nanobiotechnology. Several research fields are objects of study of Nanobiotechnology such as biogenic synthesis of m...

Controlled-release fertilizer is one of the most critical tools in agribusiness for decreasing environmental impacts. Thus, the development of bio-based systems able to induce the slow release of fertilizers has become the focus of numerous researchers. In this sense, this work presents a slow-release fertilizer prepared by melt mixing of poly(buty...

Controlled‐release fertilizer is one of the most critical tools in agribusiness for decreasing environmental impacts. Thus, the development of bio‐based systems able to induce the slow release of fertilizers has become the focus of numerous researchers. In this sense, this work presents a slow‐release fertilizer prepared by melt mixing of poly(buty...

The risks of environmental damage are inherent in oil activities, being a constant concern to our modern society. Among the remediation strategies, the biological one is safer and more inexpensive compared to physic‐chemicals approaches. Bioremediation can be enhanced using biodegradable polymers as coating materials of the nutrient release systems...

The bacteriological quality of crabs from three different mangroves (Itaóca, Suruí, and Piedade) from Rio de Janeiro state, Brazil, was investigated using conventional and molecular methods. The results revealed high counts for total coliforms in meat and hepatopancreas samples. PCR analyses identified 25 Escherichia coli colonies in the Itaóca, Pi...

The continued use of petroleum hydrocarbons as the main energy sources in the last century has generated an environmental liability that involves not only the hydrocarbon contamination but also by heavy metals that, in addition to belonging to natural composition of oil, may be associated in industrial processes as the use of refining catalysts, fo...

Large petrochemical discharges are responsible for organic and inorganic pollutants in the environment. The purpose of this study was to evaluate the influence of nickel, one of the most abundant inorganic element in crude oil and the main component of hydrogen catalysts for oil refining, on the microbial community structure in artificially petrole...

Sugar-based organogels are important esters for the cosmetic, food and pharmaceutical industries due to their intrinsic properties. Chemical routes to obtain these molecules suffer from low yields and undesirable side products. In this way, biocatalysis can be an interesting and efficient alternative, which meets the green chemistry principles. Her...

Buscou-se elaborar, validar o conteúdo de um roteiro de avaliação das condições higiênico-sa-nitárias em Serviço de Alimentação (RACHS-SA) e verificar a confiabilidade interavaliadores. O instrumento baseou-se na legislação sanitária vigente, sendo submetido aos especialistas para validação do conteúdo pela Técnica Delphi. Os especialistas tinham e...

The use of glycerol derived from biodiesel industry is an important development to add value to this actual waste. Several products can be obtained from glycerol, but acetins are very interesting molecules with a wide range of applications in pharmaceutical, cosmetics, food, and fuel industry. Herein we report our results on biocatalyzed batch and...

Probiotic foods are mainly restricted to dairy and soy products. This study aimed to develop a new probiotic beads similar to fish eggs, commonly used in oriental cuisine. Beads were produced by the extrusion encapsulation technique with calcium alginate, added to one of the following cultures: Lactobacillus rhamnosus GG ATCC 53103 and Bifidobacter...

Diacylglycerol oil has been increasingly recognized by its good nutritional properties and therefore, different technologies have been developed for obtaining it. The present work focuses on the diacylglycerol production by hydrolysis reaction of the palm oil using the PS IM and TL IM commercial lipases as biocatalysts under ultrasound irradiation....

The present work focuses on the oleic acid epoxide production by using PSCI Amano Lipase as biocatalyst in the reaction. An experimental design (central composite design - CCD) adopting surface response was applied to this purpose. Reactions were performed in a shaker equipment and different variables were investigated, such as temperature (25-55 d...

The lipase catalyzed sugar ester synthesis is an interesting strategy for producing biodegradable, non-ionic surfactants. The main disadvantage of this protocol is the long reaction time required for achieving moderated to good yields. Here, we report the esterification of steric hindered fructose derivative where important variables for batch cond...

Food microencapsulation has been an efficient way of raising food shelf life during storage. In this work passion fruit juice was encapsulated with n-octenylsuccinate-derivatised starch using a spray-dryer and stored at two different temperatures. The shelf life of vitamin C was analysed and X-ray diffraction, scanning electronic microscopy and las...

As the concern towards environmental deterioration grows worldwide, new technological achievements become essential for all countries. Among the technologies with great potential of bioremediation is microencapsulation of active material. Several studies have investigated the use of controlled release of active materials as a way of biostimulation...

Silica immobilized lipases have been prepared and utilized in the valorization of fatty acid-derived food waste streams under continuous flow conditions. Findings demonstrate that better conversions could be obtained when compared with commercially available immobilized enzymes.

An automated headspace solid-phase microextraction (HS-SPME) combined with gas chromatography-ion trap/mass spectrometry (GC-IT/MS) was developed in order to quantify a large number of volatile compounds in wines such as alcohols, ester, norisoprenoids and terpenes. The procedures were optimized for SPME fiber selection, pre-incubation temperature...

Biodegradable, biocompatible and nontoxic nonionic surfactants are widely used in food, pharmaceutical and industrial applications being commonly produced based on alkaline-catalyzed chemical glycerolysis of natural oil and fats at high temperatures and elevated pressure under nitrogen atmosphere. In this work we have optimized a biocatalytic conti...

Free fatty acids are used in many cases for the production of soaps, candles and assist processing of rubber products, but we believe that new process technology should be developed to produce products with higher added value. Monoacylglycerols (MAGs) are nonionic surfactant, highly hydrophobic and has been used as controlled release systems for dr...

Brazil is one of the major producers of sugarcane (Saccharum officinarum) in the world and consequently produces large quantities of waste such as sugarcane bagasse, which can be used as inert support for the production of aroma compounds by SSF. The aim of this study was to evaluate the centesimal composition and particle size distribution of suga...

This work aims at optimizing the use of consortiaof mesophile and thermophile microorganisms (moderate and extreme ones) in the leaching process of copper sulphidesflotation concentrate, containing approximately 30% bornite (Cu 5FeS 4) and 70% chalcopyrite (CuFeS 2), for extracting copper.The objective of the bioleaching tests was to evaluate the p...

Seven wild-type microorganism strains were used to reduce ethyl 3-oxohexanoate to ethyl (R)-3-hydroxyhexanoate. Free cells of Kluyveromyces marxianus and Aspergillus niger led to higher than 99% of conversion with higher than 99% ee. After immobilization in calcium alginate spheres, cells of K. marxianus exhibited high enantioselectivity (>99% ee)...

Microorganisms were used to reduce 4-bromoacetophenone to (S)-4-bromophenylethanol and (R)-4-bromophenylethanol. After a fractional factorial design to identify the important variables for this reaction, Geotrichum candidum provided 98.9% conversion with >99% e.e. of the (R)-isomer, while Rhodotorula rubra led to 97.6% conversion with 98.8% e.e. of...

The esterification reaction mediated by lipases was investigated applying both microwave irradiation and conventional heating in order to evaluate the existence of nonthermal microwave effects on the biodiesel synthesis. All transformations were conducted at 40 °C in both Monowave 300 and CEM Discover instruments that allowed accurate internal reac...

Food microencapsulation has been an efficient way of raising food shelf life during storage. Passion fruit juice was encapsulated in Capsul® and stored at different temperatures. The shelf life of vitamin C was analyzed and X-ray diffraction, scanning electronic microscopy, and laser diffraction analyses were performed. Samples stored at 7, 25, and...

a b s t r a c t Recognition that trans and saturated fats have negative health effects drive researchers to develop alternative systems that can structure liquid oils into semi-solid plastic pastes for food applications. Monoacylglicerols (MAG) can be used as a promising molecule to achieve this structuring so we have optimized a biocatalytic batch...

Saccharomyces cerevisiae yeast was immobilized on residual pumice for trivalent and hexavalent chromium solution adsorption inside a PVC column of 4.3 cm diameter, 140 cm length by using a novel redistribution system. Metallic solutions were fed through the packed bed column in order to establish breakthrough curves, inlet solution conditions were...

The low-cost production of cellulolytic complexes presenting high action at mild conditions and well-balanced cellulase activities is one of the major bottlenecks for the economical viability of the production of cellulosic ethanol. In the present paper, the filamentous fungus Trichoderma harzianum IOC-3844 was used for the production of cellulases...

Solid state fermentation (SSF) has been used as a model for the study of metabolism and physiology of microorganisms. The aim of the present study was to enhance 6-PP production by Trichoderma harzianum 4040 in solid state fermentation using sugarcane bagasse as a residue. A fractional factorial design was used to select the components of the nutri...

BACKGROUND: Oil spills are a frequent source of environmental contamination. As a consequence, remediation of soils, waters and sediments is a great challenge in this area of research. This study aims at using a new type of soil bioreactor (13 L bench‐scale and 800 L pilot‐scale) to treat tropical soil contaminated with petroleum. Additionally, it...

Sugarcane bagasse is an agroindustrial residue generated in large amounts in Brazil. This biomass can be used for the production of cellulases, aiming at their use in second-generation processes for bioethanol production. Therefore, this work reports the ability of a fungal strain, Trichoderma harzianum IOC-4038, to produce cellulases on a novel ma...

This work reports the application of a lipase in the 2-ethylhexyl palmitate esterification in a solvent-free system with an immobilized lipase (Lipozyme RM IM). A sequential strategy was used applying two experimental designs to optimize the 2-ethylhexyl palmitate production. An empirical model was then built so as to assess the effects of process...

Growth of deinococcus radiodurans was analysed in (i) gasoline, diesel oil with (ii) or without (iii) additives, (iv) sergipano oil and (v) arabic light oil. High microbial abundance was confirmed for many of them.

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The contamination of ecosystems with heavy metals is an important issue in current world and remediation technologies should be in according to environmental sustainability concept. Bioemulsifier are promising agents to be used in metal removal and could be effective to many applications in environmental industries. The aims of this work was screen...

The contamination of ecosystems with heavy metals is an important issue in current world and remediation technologies should be in according to environmental sustainability concept. Bioemulsifier are promising agents to be used in metal removal and could be effective to many applications in environmental industries. The aims of this work was screen...

The enantioselective reduction of ethyl benzoylacetate (EBA) into ethyl (S)-3-hydroxy-3-phenylpropanoate (S-HPPE) by nine yeast strains and three filamentous fungi strains is described. The conversion obtained was in the range 0–89% and the enantiomeric excess was 100% in many cases. Conversion levels were higher when the reduction was performed wi...

The objective of this work is to investigate the utilization of two abundant agricultural residues in Brazil for the production and application of cellulolytic enzymes. Different materials obtained after pretreatment of sugarcane bagasse, as well as pure synthetic substrates, were considered for cellulase production by Penicillium funiculosum. The...

Microorganisms were used to reduce ethyl 4-chloroacetoacetate (CAAE) to ethyl (S)-4-chloro-3-hydroxybutanoate [(S)-CHBE]. Mucor ramannianus provided 98% conversion with 84% ee. Free cells of Kluyveromyces marxianus led to 95% conversion with 81% ee. After a fractionary factorial design to study the reaction conditions, calcium alginate immobilized...

A substância 6-pentil-α-pirona (6-PP) é uma lactona com aroma característico de coco e uso aprovado pela agência americana Food and Drug Administration (FDA). O presente trabalho teve como objetivo ajustar as condições de microextração em fase sólida em headspace para a quantificação por cromatografia gasosa de 6-PP produzida pelo fungo Trichoderma...

The lactone 6-pentyl-a-pyrone (6-PP) is a coconut-like aroma compound approved by the American agency Food and Drug Administration (FDA) for food use. The aim of the present study was to improve the extraction conditions of headspace solid-phase microextraction coupled with gas chromatography to quantify the 6-PP produced by Trichoderma harzianum u...

The present paper describes a protocol for production of diacylglycerol by the partial hydrolysis of soybean oil catalyzed by lipase under ultrasound irradiation. Better yields and shorter reaction times were obtained under sonication as compared to the thermal process.

This work reports the optimization of 2-ethylhexyl palmitate production by esterification reaction in a solvent-free system using a commercial lipase as catalyst. For this, a sequential strategy was performed applying three experimental designs. An empirical model was built so as to assess the effects of process variables on the reaction conversion...

In the present work several microorganisms were screened in the reduction of methyl and ethyl acetoacetates. Good to excellent ees were obtained with up to quantitative substrate conversions. These microorganisms were also tested in the reduction of ethyl α-methylacetoacetate with good des and excellent ees. It was noticed that Kluyveromyces marxia...

The present Letter details our findings on the lipase-catalyzed Michael reactions between primary or secondary amines and acrylonitrile. Several lipases were evaluated, and good results were obtained leading to the formation of Michael adducts in shorter reaction times than the uncatalyzed reactions.

Many Trichoderma species are able to produce 6-pentyl-α-pyrone (6-PP), a lactone with coconut-like aroma. In the present work, several culture parameters were studied to enhance the production of 6-PP by Trichoderma harzianum 4040 in solid-state fermentation. Green coir powder added to a nutrient solution was used as support material for fermentati...

The application of a bacterial extracellular polymeric substance (EPS) in the bioremediation of heavy metals (Cd, Zn and Cu) by a microbial consortium in a hydrocarbon co-contaminated aqueous system was studied. At the low concentrations used in this work (1.00 ppm of each metal), it was not observed an inhibitory effect on the cellular growing. In...

Agro-industrial residues have become an important source for the production of chemical compounds using biological pathways, contributing to preservation of the environment and making the overall process economically supportable. Vanillin is a very important aromatic compound for the food, beverage, and pharmaceutical industries. The aim of the pre...

Many Trichoderma species are able to produce 6-pentyl-α-pyrone (6-PP), a lactone with coconut-like aroma. In the present work, several culture parameters were studied to enhance the production of 6-PP by Trichoderma harzianum 4040 in solid-state fermentation. Green coir powder added to a nutrient solution was used as support material for fermentati...

The application of a bacterial extracellular polymeric substance (EPS) in the bioremediation of heavy metals (Cd, Zn and Cu) by a microbial consortium in a hydrocarbon co-contaminated aqueous system was studied. At the low concentrations used in this work (1.00 ppm of each metal), it was not observed an inhibitory effect on the cellular growing. In...

Three hundred and thirty nine lactic bacteria strains isolated from food samples were screened for antimicrobial activity. Only one strain isolated from meat pie and identified as Enterococcus faecium produced a bacteriocin-like inhibitory substance (BLIS) showing activity against Enterococcus, Leuconostoc, Lactobacillus, Listeria, Corynebacterium...

The needing of a bacterial extracellular polymeric substance (EPS) application in bioremediation of an aqueous system containing glucose and/or gasoline and/or heavy metals (Cd 2+ , Zn 2+ and Cu 2+ ) by two different microbial consortia was studied. At the low concentrations (1.00 ppm of each metal), it was observed an inhibitory effect on the meta...

A efetividade da aplicação dos processos biológicos no tratamento de solos contaminados por hidrocarbonetos é frequentemente influenciada pela habilidade da população microbiana nativa em assimilar e metabolizar os contaminantes. Geralmente a confirmação da eficácia de um processo de biorremediação ocorre por meio da avaliação de parâmetros químico...

The degradation of phenol by a hybrid process (activated sludge + photocatalysis) in a high salinity medium (50 g L−1 of chloride) has been investigated. The sludge used from a municipal wastewater facility was adapted to the high salt concentrations prior to use. The photocatalytic conditions were optimized by means of a factorial experimental des...

The microbial reduction of alpha-methyl, allyl and benzyl derivatives of alpha-acetyl-gamma-butyrolactones was carried out. It has been shown that different microorganisms, Kluyveromyces marxianus, Hansenula sp., Geotrichum candidum and Aspergillus niger, are capable to carry out the enantiospecific/selective reduction of these compounds. In the ex...

Bioremediation is an attractive alternative to treat soils contaminated with petroleum hydrocarbons. However, the effectiveness of biodegradation process can be limited by both contaminant characteristics and its bioavailability in soil. This work aims at establishing a preliminary procedure to identify the main factor (hydrocarbon recalcitrance or...

This work was conducted to investigate the possibility of using stillage from ethanol distilleries as substrate for sulfate reducing bacteria (SRB) growth and to evaluate the removal efficiency of heavy metals present in wastewaters containing sulfates. The experiments were carried out in a continuous bench-scale Upflow Anaerobic Sludge Blanket rea...

Trivalent and hexavalent chromium continuous biosorption was studied using residual brewer Saccharomyces cerevisiae immobilized in volcanic rock. The columns used in the process had a diameter of 4.5 cm and a length of 140 cm, working at an inlet flow rate of 15 mL/min. Breakthrough curves were used to study the yeast biosorption behavior in the pr...

The optimal conditions for salicylic acid biodegradation by Pseudomonas fluorescens HK44 were determined in this study with the intention to create a microbial sensor. Kinetic experiments permitted a definition of 60 and 30min the time needed to achieve the maximum degradation of salicylic acid presented in a medium with and without yeast extract,...

The ability of Geotrichum candidum to produce fruity aroma in food grade sucrose, molasses, corn steep liquor and peptone based culture media was tested by sensory evaluation and analyzed by gas chromatography - mass spectrometry. A strong and sweet fruity aroma was produced from molasses, with peptone or corn steep liquor stimulating aroma product...

This work deals with the development of a digital image analysis procedure to characterize microbial flocs obtained in three different WWTP: a bench-scale Sequencing Batch Reactor (SBR) dealing with phenol and nitrogen biological removal, a municipal treatment unit (Ilha do Governador, Rio de Janeiro, Brazil) and an industrial wastewater treatment...

Herein, different microorganisms were tested in the enantioselective reduction of ethyl 2-oxo-4-phenylbutyrate in aqueous medium for the preparation of ethyl (R)-2-hydroxy-4-phenylbutyrate, a key intermediate in the production of angiotensin converting enzyme (ACE) inhibitors. The use of Pichia angusta led to the (R)-enantiomer in 81% ee.

Isomers of α-1′-hydroxyethyl-γ-butyrolactone can be considered as potential GHB receptor ligands designed by the molecular hybridization of GLB 2 and GHV 4. Using Aspergillus niger, Geotrichum candidum, and Kluyveromyces marxianus, it was possible to obtain (+)-(3R,1′S)-α-1′-hydroxyethyl-γ-butyrolactone in good to excellent conversions, diastereois...

Different microorganisms (MOs) were used to carry out the enantioselective reduction of ethyl-2-oxo-4-phenylbutanoate to (S)-(+)-2-hydroxy-4-phenylbutanoate or (R)-(+)-2-hydroxy-4-phenylbutanoate. Commercially available Saccharomyces cerevisiae and Dekera sp. led to over 92% ee of (S)-(+)-2-hydroxy-4-phenylbutanoate. Kluyveromyces marxianus gave th...

O objetivo deste trabalho foi efetuar revisao do conhecimento sobre tanase, apontando necessidades e perspectivas de utilizacao, em especial para a area de alimentos. Foram enfatizados topicos como importância fisiologica da tanase e seu mecanismo de acao, sua producao por microrganismos, os metodos analiticos para sua determinacao, a sua producao...

Investigou-se o aproveitamento da casca do coco verde, mediante fermentacao semisolida, para producao de enzimas. A casca de coco foi previamente desidratada, moida e classificada em tres diferentes granulometrias, ou seja, 14, 28 e 32 mesh Tyler. Todas as enzimas obtidas tiveram sua producao maxima na faixa de 24 e 96 horas, o que corresponde ao t...

Biosorption of heavy metals by gram-positive, non-pathogenic and non-toxicogenic Paenibacillus polymyxa P13 was evaluated. Copper was chosen as a model element because it is a pollutant originated from several industries. An EPS (exopolysaccharide)-producing phenotype exhibited significant Cu(II) biosorption capacity. Under optimal assay conditions...

Bioactivation, a procedure to obtain anaerobic sulphidogenic sludge, was developed in order to increase sulphate reduction and, consequently, sulphide production to remove metals from effluents. This procedure, in which the source of carbon/energy (lactate) is gradually replaced, consisted of three operational conditions. It was observed that bioac...

Nos estudos em análise sensorial a limitação fisiológica dos órgãos dos sentidos dos provadores é um dos fatores a se levar em consideração no planejamento dos testes. O objetivo deste estudo foi validar um desenho experimental para testes comparativos com muitas amostras. Cultivos de leveduras produtoras de aroma frutal foram escolhidas por provad...

Nos estudos em análise sensorial a limitação fisiológica dos órgãos dos sentidos dos provadores é um dos fatores a se levar em consideração no planejamento dos testes. O objetivo deste estudo foi validar um desenho experimental para testes comparativos com muitas amostras. Cultivos de leveduras produtoras de aroma frutal foram escolhidas por provad...

An experimental design technique has been used to investigate the biosorption of chromium from water solutions, simulating typical tanning effluents. The United States Environmental Protection Agency (EPA) usually allows solutions containing heavy metals to be discharged if the concentration is less than 5.0 mg/L. The removal of Cr3+ and Cr6+ was s...

Saccharomyces cerevisiae, Hansenula sp., Dekera sp. and Kluyveromyces marxianus free and immobilized and free Geotrichum sp. have been used in the reduction of ethyl benzoylacetate yielding, in up to 99% ees, ethyl (S)-3-hydroxi-3-phenylpropionate, a suitable intermediate for the production of fluoxetine.

The facility with which hydrocarbons can be removed from soils varies inversely with aging of soil samples as a result of weathering. Weathering refers to the result of biological, chemical and physical processes that can affect the type of hydrocarbons that remain in a soil. These processes enhance the sorption of hydrophobic organic contaminants...

The strain SVGG16 isolated from tropical soil in Brazil and identified as Serratia sp. was selected as a promising biosurfactant producer using atypic growth conditions including ethanol-blended gasoline as the sole carbon source. Important parameters for biosurfactant production were selected through experimental design. Results demonstrated that...

This study presents the bactericidal activity of titanium dioxide photocatalysis, using as model Escherichia coli and Pseudomonas sp. cells. It was observed that the process efficiency is related to initial cell concentration, light intensity, UV irradiation exposure time, TiO2 concentration increase. The ultimate removal efficiency was above 99.9%...

A bioluminescence detection system using Pseudomonas fluorescens HK44 was applied for naphthalene measurement in the range 0–0.5 mg l−1, lower than the maximum of 1 mg l−1 recommended by EPA. Diluted sample injections of naphthalene were added to 0.2 or 0.4 g l−1 cellular concentrations used in the detection medium. The lowest cell density (0.2 g l...