Optimized biotransformation of acid-treated water melon peel hydrolyzate into ethanol / Biotransformação otimizada de hidrolisado de casca de melancia tratada com ácido em etanol

Abstract Today, global focus of research is to explore the solution of energy crisis and environmental pollution. Like other agricultural countries, bulk quantities of watermelon peels (WMP) are disposed-off in environment as waste in Pakistan and appropriate management of this waste is the need of hour to save environment from pollution. The work emphasizes the role of ethanologenic yeasts to utilize significant sugars present in WMP for low-cost bioethanol fermentation. Dilute hydrochloric acid hydrolysis of WMP was carried out on optimized conditions employing RSM (response surface methodology) following central composite design (CCD). This experimental design is based on optimization of ethanologenesis involving some key independent parameters such as WMP hydrolysate and synthetic media ratio (X1), incubation temperature (X2) and incubation temperature (X3) for maximal ethanol yield exploiting standard (Saccharomyces cerevisiae K7) as well as experimental (Metchnikowia cibodasensisY34) yeasts. The results revealed that maximal ethanol yields obtained from S. cerevisiae K7 was 0.36±0.02 g/g of reducing sugars whereas M. cibodasensisY34, yielded 0.40±0.01 g ethanol/g of reducing sugars. The yeast isolate M. cibodasensisY34 appeared as promising ethanologen and embodies prospective potential for fermentative valorization of WMP-to-bioethanol.

Resumo Hoje, o foco global da pesquisa é explorar a solução da crise energética e da poluição ambiental. Como em outros países agrícolas, grandes quantidades de cascas de melancia (WMP) são descartadas como resíduos no meio ambiente no Paquistão, mas a gestão adequada desses resíduos é a mais recente solução para salvar o meio ambiente da poluição. O trabalho enfatiza o papel das leveduras etanologênicas para utilizar açúcares significativos presentes no WMP para fermentação de bioetanol de baixo custo. A hidrólise de ácido clorídrico diluído de WMP foi realizada em condições otimizadas empregando RSM (metodologia de superfície de resposta) e seguindo o projeto de composto central (CCD). Este projeto experimental é baseado na otimização da etanologenesis envolvendo alguns parâmetros independentes importantes, como hidrolisado de WMP e razão de meio sintético (X1), temperatura de incubação (X2) e temperatura de incubação (X3) para rendimento máximo de etanol explorando o padrão (Saccharomyces cerevisiae K7) também como leveduras experimentais (Metchnikowia cibodasensis Y34). Os resultados revelaram que os rendimentos máximos de etanol obtidos a partir de S. cerevisiae K7 foi de 0,36 ± 0,02 g / g de açúcares redutores, enquanto M. cibodasensis Y34 rendeu 0,40 ± 0,01 g de etanol / g de açúcares redutores. O isolado de levedura M. cibodasensis Y34 apareceu como um etanologeno promissor e incorpora um potencial prospectivo para a valorização fermentativa de WMP em bioetanol.

Fungal decomposition of chicken-feather waste in submerged and solid-state fermentation / Decomposição fúngica de resíduos de pena de frango em fermentação submersa e de estado sólido

Poultry industry is expanding rapidly and producing million tons of feather waste annually. Massive production of keratinaceous byproducts in the form of industrial wastes throughout the world necessitates its justified utilization. Chemical treatment of keratin waste is proclaimed as an eco-destructive approach by various researchers since it generates secondary pollutants. Keratinase released by a variety of microbes (bacteria and fungi) can be used for the effective treatment of keratin waste. Microbial degradation of keratin waste is an emerging and eco-friendly approach and offers dual benefits, i.e., treatment of recalcitrant pollutant (keratin) and procurement of a commercially important enzyme (keratinase). This study involves the isolation, characterization, and potential utility of fungal species for the degradation of chicken-feather waste through submerged and solid-state fermentation. The isolated fungus was identified and characterized as Aspergillus (A.) flavus. In a trial of 30 days, it was appeared that 74 and 8% feather weight was reduced through sub-merged and solid-state fermentation, respectively by A. flavus. The pH of the growth media in submerged fermentation was changed from 4.8 to 8.35. The exploited application of keratinolytic microbes is, therefore, recommended for the treatment of keratinaceous wastes to achieve dual benefits of remediation.

A indústria avícola está se expandindo rapidamente e produzindo milhões de toneladas de resíduos de penas anualmente. A produção massiva de subprodutos queratinosos na forma de resíduos agrícolas e industriais em todo o mundo exige sua utilização justificada. O tratamento químico de resíduos de queratina é proclamado como uma abordagem ecodestrutiva por vários pesquisadores, uma vez que gera poluentes secundários. A queratinase liberada por uma variedade de micróbios (bactérias e fungos) pode ser usada para o tratamento eficaz de resíduos de queratina. A degradação microbiana de resíduos de queratina é uma abordagem emergente e ecológica e oferece benefícios duplos, ou seja, tratamento de poluente recalcitrante (queratina) e obtenção de uma enzima comercialmente importante (queratinase). Este estudo envolve o isolamento, caracterização e utilidade potencial de espécies de fungos para a degradação de resíduos de penas de frango por meio da fermentação submersa e em estado sólido. O fungo isolado foi identificado e caracterizado como Aspergillus (A.) flavus. Em um ensaio de 30 dias, constatou-se que 74% e 8% do peso das penas foram reduzidos por A. flavus, respectivamente, por meio da fermentação submersa e em estado sólido. O pH do meio de crescimento em fermentação submersa foi alterado de 4,8 para 8,35. A aplicação explorada de micróbios queratinolíticos é, portanto, recomendada para o tratamento de resíduos ceratinosos para obter benefícios duplos de remediação.

Sobre dias em que me senti sem ar: desassossegos do pesquisar / On days when i felt breathless: unrest of search / Sobre días que me sentí sin aliento: disurbios de investigación

Resumo Conceitos como o de alteridade, encontro de saberes, polifasia cognitiva, o princípio de familiaridade e de representações sociais operaram na complexa tarefa de compreender como os encontros entre profissionais e usuários sustentavam e/ou transformavam as práticas de acolhimento. Entretanto, a experiência da minha pesquisa de doutorado me levou a questionar os próprios conceitos utilizados da Teoria das Representações Sociais. Ao final do ensaio, após discutir aspectos teórico-metodológicos, o princípio de familiaridade e a questão da tensão e dos afetos nas representações sociais, espero evidenciar como o movimento provocado pelo encontro com usuários e profissionais de uma Rede de Atenção Psicossocial levou-me a questionar pontos essenciais da teoria: o papel domesticador das representações, a forma ainda estática de evidenciar os fenômenos, a separação entre um sujeito que representa e o objeto representado e a dificuldade em usar suas ferramentas conceituais para acompanhar processos me fazem repensar meu lugar e minha função de pesquisador.

Abstract Concepts such as alterity, encounter of knowledge, cognitive polyphasia, the principle of familiarity and the very concept of social representations operated in the complex task of understanding how the encounters between professionals and users supported and / or transformed user embracement practices. However, the experience of my doctoral research led me to question the very concepts used in the Theory of Social Representations. At the end of the essay, after discussing theoretical and methodological aspects, the principle of familiarity and the issue of tension and affects in social representations, I hope to show how the movement caused by the encounter with users and professionals of a Psychosocial Care Network, led me to question essential points of the theory: the domesticating role of representations, the still static way of showing phenomena, the separation between a subject that represents and the object represented and the difficulty in using their conceptual tools to accompany processes makes me rethink my place and role as a researcher.

Resumen Conceptos como la alteridad, el encuentro de saberes, la polifasia cognitiva, el principio de familiaridad y el concepto mismo de representaciones sociales operaron en la compleja tarea de comprender cómo los encuentros entre profesionales y usuarios apoyaron y / o transformaron las prácticas de acogimiento. Sin embargo, la experiencia de mi investigación doctoral me llevó a cuestionar los propios conceptos utilizados en la Teoría de las Representaciones Sociales. Al final del ensayo, después de discutir aspectos teóricos y metodológicos, el principio de familiaridad y el tema de tensión y afectos en las representaciones sociales, Espero mostrar cómo el movimiento provocado por el encuentro con usuarios y profesionales de una Red de Atención Psicosocial, me llevó a cuestionar puntos esenciales de la teoría: el rol domesticador de las representaciones, la forma todavía estática de mostrar los fenómenos, la separación entre un sujeto que representa y el objeto representado y la dificultad para utilizar sus herramientas conceptuales para acompañar procesos, me hace repensar mi lugar y rol como investigador.

Estudo de estabilidade de anfetaminas e produtos de biotransformação de cocaína e tetraidrocanabinol em amostras de urina seca em papel (dried urine spots) / Stability study of amphetamines, biotransformation products of cocaine and tetrahydrocannabinol in dried urine spots

O número de pessoas utilizando substâncias ilícitas de forma recreativa aumenta a cada ano, chamando a atenção de estudiosos de diversas áreas do conhecimento. Com isso, a demanda de exames toxicológicos exigida para trabalhadores, vítimas de crimes e esportistas também tem crescido. A amostra biológica mais utilizada para análises toxicológicas continua sendo a urina, visto que sua obtenção é menos invasiva, possibilita coletar grande volume de amostra e pode-se detectar substâncias até dias após ter ocorrido a exposição ou consumo. Entretanto, estas amostras necessitam de um grande volume físico para serem armazenadas e transportadas aos laboratórios, devendo ser mantidas em temperatura baixa e controlada para conservação. Outro ponto a se considerar é a quantidade de amostra insuficientemente coletada, ou extravasamento do conteúdo, contaminando outras amostras e muitas vezes, inviabilizando a análise. Uma alternativa recente para tais problemas é utilizar a técnica chamada de dried urine spots (DUS), onde poucos microlitros de urina são colocados em um papel absorvente e secos sob temperatura ambiente, preservando de agentes degradantes os componentes presentes na urina. Assim, o objetivo deste trabalho é avaliar a estabilidade das substâncias do presente estudo em alta temperatura, temperatura ambiente e em temperaturas de 4°C e -20°C. Para este fim, foi necessário desenvolver, validar e aplicar métodos de extração e determinação de anfetaminas e produtos de biotransformação de cocaína e tetraidrocanabinol carboxílico (THCCOOH) em amostras dried urine spot, utilizando cromatografia líquida acoplada à espectrometria de massas. Os picos foram identificados por UPLC-ESI-MS/MS, com tempo total de 5 mins utilizando fase A- água, formiato de amônio e 0,1% ácido fórmico, e B- metanol: acetonitrila (6:4) + 0,1% de ácido fórmico. A extração foi feita utilizando acetonitrila: metanol: acetona (1:1:1) +ácido fórmico 0,1%. Não foi possível iniciar a validação de THCCOOH, visto uma possível complexação do analito com o papel. Para as outras substâncias, o método cromatográfico desenvolvido se mostrou eficiente e seletivo, com LOD e LOQ de 10 ng/mL para todos os analitos, sendo linear até 1000 ng/mL, atendeu as especificações de precisão e exatidão e carryover. As amostras permaneceram estáveis ao longo de 32 dias nas temperaturas estudadas, demonstrando a segurança em se utilizar a técnica de DUS para armazenamento e transporte de amostras biológicas dentro da faixa de temperatura do estudo até 32 dias

The number of people using illegal substances in a recreational way increases each year, drawing the attention of scholars from different areas of knowledge. As a result, the demand for workplaces drug tests, toxicological tests for victims of crimes and dopping has also grown. The biological sample most used for toxicological tests remains urine, since obtaining it is less invasive, it is possible to collect a large volume of sample and it is possible to detect substances up to days after exposure or consumption has occurred. However, these samples require a large physical volume to be stored and transported to the laboratories, and must be kept at a low temperature for conservation. Another point to consider is the amount of sample insufficiently collected, or leakage of the content, causing contamination of other samples and often making the analysis unfeasible. A recent alternative to such problems is to use "dried urine spots" (DUS), where few microliters of urine are placed on absorbent paper and dried at room temperature, preserving the components present in the urine from degrading agents. Thus, the objective of this work is to evaluate the stability of the substances in this study at high temperature, room temperature and at temperatures of 4°C and -20°C. For this purpose, it was necessary to develop, validate and apply methods of extraction and determination of amphetamines and biotransformation products of cocaine and carboxylic tetrahydrocannabinol (THCCOOH) in dried urine spot samples, using liquid chromatography coupled to mass spectrometry (LC-MS). The peaks were identified liquid chromatography coupled to a mass spectrometer (UPLC-ESI-MS/MS), with a total time of 5 mins using phase A- water, ammonium formate and 0.1% formic acid, and B- methanol: acetonitrile (6:4) + 0.1% formic acid. Extraction was done using acetonitrile: methanol: acetone (1:1:1) + 0.1% formic acid. It was not possible to perform the validation of THCCOOH, given a possible complexation of the analyte with the paper. To the others substances, the chromatographic method developed proved to be efficient and selective, with LOD and LOQ of 10 ng/mL for all analytes, being linear up to 1000 ng/mL, meeting the specifications of precision and accuracy and carryover. The samples remained stable for 32 days at the temperatures studied, demonstrating the safety of using the DUS technique for storage and transport of biological samples until 32 days on temperature range studied

Estudo de estabilidade de anfetaminas e produtos de biotransformação de cocaína e tetraidrocanabinol em amostras de urina seca em papel (dried urine spots) / Stability study of amphetamines, biotransformation products of cocaine and tetrahydrocannabinol in dried urine spots

O número de pessoas utilizando substâncias ilícitas de forma recreativa aumenta a cada ano, chamando a atenção de estudiosos de diversas áreas do conhecimento. Com isso, a demanda de exames toxicológicos exigida para trabalhadores, vítimas de crimes e esportistas também tem crescido. A amostra biológica mais utilizada para análises toxicológicas continua sendo a urina, visto que sua obtenção é menos invasiva, possibilita coletar grande volume de amostra e pode-se detectar substâncias até dias após ter ocorrido a exposição ou consumo. Entretanto, estas amostras necessitam de um grande volume físico para serem armazenadas e transportadas aos laboratórios, devendo ser mantidas em temperatura baixa e controlada para conservação. Outro ponto a se considerar é a quantidade de amostra insuficientemente coletada, ou extravasamento do conteúdo, contaminando outras amostras e muitas vezes, inviabilizando a análise. Uma alternativa recente para tais problemas é utilizar a técnica chamada de dried urine spots (DUS), onde poucos microlitros de urina são colocados em um papel absorvente e secos sob temperatura ambiente, preservando de agentes degradantes os componentes presentes na urina. Assim, o objetivo deste trabalho é avaliar a estabilidade das substâncias do presente estudo em alta temperatura, temperatura ambiente e em temperaturas de 4°C e -20°C. Para este fim, foi necessário desenvolver, validar e aplicar métodos de extração e determinação de anfetaminas e produtos de biotransformação de cocaína e tetraidrocanabinol carboxílico (THCCOOH) em amostras dried urine spot, utilizando cromatografia líquida acoplada à espectrometria de massas. Os picos foram identificados por UPLC-ESI-MS/MS, com tempo total de 5 mins utilizando fase A- água, formiato de amônio e 0,1% ácido fórmico, e B- metanol: acetonitrila (6:4) + 0,1% de ácido fórmico. A extração foi feita utilizando acetonitrila: metanol: acetona (1:1:1) +ácido fórmico 0,1%. Não foi possível iniciar a validação de THCCOOH, visto uma possível complexação do analito com o papel. Para as outras substâncias, o método cromatográfico desenvolvido se mostrou eficiente e seletivo, com LOD e LOQ de 10 ng/mL para todos os analitos, sendo linear até 1000 ng/mL, atendeu as especificações de precisão e exatidão e carryover. As amostras permaneceram estáveis ao longo de 32 dias nas temperaturas estudadas, demonstrando a segurança em se utilizar a técnica de DUS para armazenamento e transporte de amostras biológicas dentro da faixa de temperatura do estudo até 32 dias

The number of people using illegal substances in a recreational way increases each year, drawing the attention of scholars from different areas of knowledge. As a result, the demand for workplaces drug tests, toxicological tests for victims of crimes and dopping has also grown. The biological sample most used for toxicological tests remains urine, since obtaining it is less invasive, it is possible to collect a large volume of sample and it is possible to detect substances up to days after exposure or consumption has occurred. However, these samples require a large physical volume to be stored and transported to the laboratories, and must be kept at a low temperature for conservation. Another point to consider is the amount of sample insufficiently collected, or leakage of the content, causing contamination of other samples and often making the analysis unfeasible. A recent alternative to such problems is to use "dried urine spots" (DUS), where few microliters of urine are placed on absorbent paper and dried at room temperature, preserving the components present in the urine from degrading agents. Thus, the objective of this work is to evaluate the stability of the substances in this study at high temperature, room temperature and at temperatures of 4°C and -20°C. For this purpose, it was necessary to develop, validate and apply methods of extraction and determination of amphetamines and biotransformation products of cocaine and carboxylic tetrahydrocannabinol (THCCOOH) in dried urine spot samples, using liquid chromatography coupled to mass spectrometry (LC-MS). The peaks were identified liquid chromatography coupled to a mass spectrometer (UPLC-ESI-MS/MS), with a total time of 5 mins using phase A- water, ammonium formate and 0.1% formic acid, and B- methanol: acetonitrile (6:4) + 0.1% formic acid. Extraction was done using acetonitrile: methanol: acetone (1:1:1) + 0.1% formic acid. It was not possible to perform the validation of THCCOOH, given a possible complexation of the analyte with the paper. To the others substances, the chromatographic method developed proved to be efficient and selective, with LOD and LOQ of 10 ng/mL for all analytes, being linear up to 1000 ng/mL, meeting the specifications of precision and accuracy and carryover. The samples remained stable for 32 days at the temperatures studied, demonstrating the safety of using the DUS technique for storage and transport of biological samples until 32 days on temperature range studied

Positive improvement in palatability of metabolic formula with the use of miraculin protein in patients with inborn errors of metabolism and healthy adults / Cambio positivo en la palatabilidad de la fórmula metabólica con el uso de la proteína miraculina en pacientes con errores innatos del metabolismo y adultos sanos

ABSTRACT As palatability of medical formulas has been documented as unpleasant, new options are required to improve acceptance and adherence in people with inborn errors of metabolism (IEM). Miracle fruit (Synsepalum dulcificum) has a glycoprotein named miraculin that transforms a sour, bitter taste such as the one found in metabolic formula, into a sweet perception. The objective of this work is to analyze the response in the taste perception of metabolic formula with the use of the miraculin tablets in patients with IEM and healthy adults. To test this hypothesis a prospective, longitudinal, quasi-experimental, analytical study was performed. Patients with IEM and healthy adults were recruited. All participants assessed 3 different liquids (lemon, apple cider vinegar and metabolic formula) before and after the administration of miraculin tablets and completed a questionnaire. The sensory responses were evaluated using hedonic scales, analyzed with nonparametric tests for paired data. Seven patients with IEM and 14 healthy subjects were included. After miraculin intake 57% of patients (Z ≤ -1.89 p= 0.059) and healthy adults (Z≤ -2.31 p= 0.021) had a positive change in their taste perception. The absolute frequency of patients who did not like the metabolic formula decreased from 4 to 1, and in patients who liked it or loved, it increased from 0 to 2 and from 0 to 1 respectively; the frequency of patients who perceived the metabolic formula as indifferent or hated it, did not change. Response in taste perception had a positive change of 57% in both groups. The use of miraculin tablets may improve palatability of metabolic formula.

RESUMEN La palatabilidad de las fórmulas médicas se ha reportado como desagradable, se requieren nuevas opciones para mejorar la aceptación en personas con errores innatos del metabolismo (EIM). La fruta milagrosa (Synsepalum dulcificum) contiene una glucoproteína llamada miraculina que transforma el sabor agrio y amargo en dulce. El objetivo fue analizar la respuesta en la percepción del sabor de la fórmula metabólica con el uso de las tabletas de miraculina en pacientes con EIM y adultos sanos. Se realizó un estudio analítico prospectivo, longitudinal, cuasi-experimental. Los participantes evaluaron la percepción de 3 líquidos (limón, vinagre de manzana y fórmula metabólica) antes y después de la administración de tabletas de miraculina y completaron un cuestionario. Las respuestas sensoriales se evaluaron mediante escalas hedónicas, analizadas con pruebas no paramétricas para datos pareados. Se incluyeron 7 pacientes con EIM y 14 adultos sanos. Después de la miraculina el 57% de los pacientes (Z ≤ -1,89 p= 0,059) y adultos sanos (Z≤ -2,31 p= 0,021) tuvieron un cambio positivo en su percepción del sabor. La frecuencia absoluta de pacientes a los que no les gustó la fórmula disminuyó de 4 a 1, y en quienes les gustó o les encantó, aumentó de 0 a 2 y de 0 a 1 respectivamente; la frecuencia de los pacientes que percibieron la fórmula como indiferente u odiada, no cambió. La respuesta en la percepción del sabor cambió positivamente en el 57% en ambos grupos. El uso de miraculina puede mejorar la palatabilidad de la fórmula metabólica.

Effect of Chitosan Addition in Whey-based Biodegradable Films

Abstract Whey, a by-product of dairy industry, is a feedstock widely employed in the production of biodegradable films. However, these films present some limitations when considering the performance of synthetic polymers, especially biological transformation by decomposition. This work aimed to evaluate the effects of chitosan addition to whey-based films to improve films physical-chemical properties and resistance to microbial degradation. The results showed that there was an interaction effect between the chitosan concentration and the storage time for the physical-chemical properties of elongation at break and opacity. There was statistical difference among the formulations; however, for the moisture content and film thickness, there was no interaction effect between the formulation and the storage time. The films with 1.5 and 3.0 wt.% chitosan presented a yellowish hue, characteristic of the polysaccharide; this could also be detected by SEM analysis. The films presented an excellent biodegradability, being decomposed in about 8 days. Considering all chitosan contents tested had similar performances, the chitosan content of 0.15 wt.% was the one with the better cost-benefit relation.

Transformation of Brewery Subproducts into Valuable Biomass Using Mixotrophic Culture of Chlorella pyrenoidosa and Associated Bacteria

Abstract To develop a biorefinery concept applied in the brewery industry, Chlorella pyrenoidosa and a consortium of associated bacteria were cultivated mixotrophically in a continuous photobioreactor using brewery low-value subproducts as an integrative process. Beer production residues were biochemically characterized to assess the most promising options to be used as a nutrient source for microalgal cultivation. Due to its physical and chemical properties, pre-treated weak wort was used to prepare an organic complex culture medium for microalgal biotransformation. Filtration and nitrogen supplementation were necessary to improve nutrient removal and biomass productivity. Maximal removal of nitrate and phosphate obtained were 90% and 100% respectively. Depending on operation conditions, total carbohydrates depuration ranged from 50 - 80%. The initial concentration of total carbohydrates of the weak wort must be adjusted to 2 - 4g/L to maintain a stable equilibrium between microalgal and bacterial growth. The biochemical composition of produced biomass varied depending on the cultivation conditions as well as on its final use. Upon continuous mixotrophic conditions evaluated in this study, C. pyrenoidosa was composed mainly of carbohydrates and protein.

Direct biodegradation of eugenol to coniferyl aldehyde and other higher value-added products by Gibberella fujikuroi ZH-34

BACKGROUND: Eugenol is an economically favorable substrate for the microbial biotransformation of aromatic compounds. Coniferyl aldehyde is one kind of aromatic compound that is widely used in condiment and medical industries; it is also an important raw material for producing other valuable products such as vanillin and protocatechuic acid. However, in most eugenol biotransformation processes, only a trace amount of coniferyl aldehyde is detected, thus making these processes economically unattractive. As a result, an investigation of new strains with the capability of producing more coniferyl aldehyde from eugenol is required. RESULTS: We screened a novel strain of Gibberella fujikuroi, labeled as ZH-34, which was capable of transforming eugenol to coniferyl aldehyde. The metabolic pathway was analyzed by high-performance liquid chromatography­mass spectrometry and transformation kinetics. The culture medium and biotransformation conditions were optimized. At a 6 h time interval of eugenol fed-batch strategy, 3.76 ± 0.22 g/L coniferyl aldehyde was obtained, with the corresponding yield of 57.3%. CONCLUSIONS: This work improves the yield of coniferyl aldehyde with a biotechnological approach. Moreover, the fed-batch strategy offers possibility for controlling the target product and accumulating different metabolites

Optimization of liquid fermentation conditions for biotransformation zein by Cordyceps militaris 202 and characterization of physicochemical and functional properties of fermentative hydrolysates

Abstract Cordyceps militaris 202 is a potential fungus for biotransformation zein, due to its various proteases, high tolerance and viability in nature. In this article, single factor experiment and response surface methodology were applied to optimize the liquid fermentation conditions and improve the ability of biotransformation zein. The optimized fermentation conditions were as follows: inoculum concentration of 19%, volume of liquor of 130 mL/500 mL and pH of 4.7. Under this condition, the degree of hydrolysis (DH) was 27.31%. The zein hydrolysates from fungi fermentation maintained a high thermal stability. Compared to the original zein, the zein hydrolysates were found to have high solubility, which most likely results in improved foaming and emulsifying properties. Overall, this research demonstrates that hydrolysis of zein by C. militaris 202 is a potential method for improving the functional properties of zein, and the zein hydrolysates can be used as functional ingredients with an increased antioxidant effect in both food and non-food applications.

The potential of the newly isolated thermotolerant yeast Pichia kudriavzevii RZ8-1 for high-temperature ethanol production

Abstract High potential, thermotolerant, ethanol-producing yeasts were successfully isolated in this study. Based on molecular identification and phylogenetic analysis, the isolated thermotolerant yeasts were clustered in the genera of Pichia kudriavzevii, Candida tropicalis, Candida orthopsilosis, Candida glabrata and Kodamea ohmeri. A comparative study of ethanol production using 160 g/L glucose as a substrate revealed several yeast strains that could produce high ethanol concentrations at high temperatures. When sugarcane bagasse (SCB) hydrolysate containing 85 g/L glucose was used as a substrate, the yeast strain designated P. kudriavzevii RZ8-1 exhibited the highest ethanol concentrations of 35.51 g/L and 33.84 g/L at 37 °C and 40 °C, respectively. It also exhibited multi-stress tolerance, such as heat, ethanol and acetic acid tolerance. During ethanol fermentation at high temperature (42 °C), genes encoding heat shock proteins (ssq1 and hsp90), alcohol dehydrogenases (adh1, adh2, adh3 and adh4) and glyceraldehyde-3-phosphate dehydrogenase (tdh2) were up-regulated, suggesting that these genes might play a crucial role in the thermotolerance ability of P. kudriavzevii RZ8-1 under heat stress. These findings suggest that the growth and ethanol fermentation activities of this organism under heat stress were restricted to the expression of genes involved not only in heat shock response but also in the ethanol production pathway.

Anaerobic biodegradation of benzo(a)pyrene by a novel Cellulosimicrobium cellulans CWS2 isolated from polycyclic aromatic hydrocarbon-contaminated soil

Abstract Cellulosimicrobium cellulans CWS2, a novel strain capable of utilizing benzo(a)pyrene (BaP) as the sole carbon and energy source under nitrate-reducing conditions, was isolated from PAH-contaminated soil. Temperature and pH significantly affected BaP biodegradation, and the strain exhibited enhanced biodegradation ability at temperatures above 30 °C and between pH 7 and 10. The highest BaP removal rate (78.8%) was observed in 13 days when the initial BaP concentration was 10 mg/L, and the strain degraded BaP at constant rate even at a higher concentration (50 mg/L). Metal exposure experimental results illustrated that Cd(II) was the only metal ion that significantly inhibited biodegradation of BaP. The addition of 0.5 and 1.0 g/L glucose enhanced BaP biodegradation, while the addition of low-molecular-weight organic acids with stronger acidity reduced BaP removal rates during co-metabolic biodegradation. The addition of phenanthrene and pyrene, which were degraded to some extent by the strain, showed no distinct effect on BaP biodegradation. Gas chromatography-mass spectrometry (GC-MS) analysis revealed that the five rings of BaP opened, producing compounds with one to four rings which were more bioavailable. Thus, the strain exhibited strong BaP degradation capability and has great potential in the remediation of BaP-/PAH-contaminated environments.

Efficiency of decolorization of different dyes using fungal biomass immobilized on different solid supports

Abstract Different technologies may be used for decolorization of wastewater containing dyes. Among them, biological processes are the most promising because they seem to be environmentally safe. The aim of this study was to determine the efficiency of decolorization of two dyes belonging to different classes (azo and triphenylmethane dyes) by immobilized biomass of strains of fungi (Pleurotus ostreatus - BWPH, Gleophyllum odoratum - DCa and Polyporus picipes - RWP17). Different solid supports were tested for biomass immobilization. The best growth of fungal strains was observed on the washer, brush, grid and sawdust supports. Based on the results of dye adsorption, the brush and the washer were selected for further study. These solid supports adsorbed dyes at a negligible level, while the sawdust adsorbed 82.5% of brilliant green and 19.1% of Evans blue. Immobilization of biomass improved dye removal. Almost complete decolorization of diazo dye Evans blue was reached after 24 h in samples of all strains immobilized on the washer. The process was slower when the brush was used for biomass immobilization. Comparable results were reached for brilliant green in samples with biomass of strains BWPH and RWP17. High decolorization effectiveness was reached in samples with dead fungal biomass. Intensive removal of the dyes by biomass immobilized on the washer corresponded to a significant decrease in phytotoxicity and a slight decrease in zootoxicity of the dye solutions. The best decolorization results as well as reduction in toxicity were observed for the strain P. picipes (RWP17).

Enzymatic reactions involving the heteroatoms from organic substrates

ABSTRACT Several enzymatic reactions of heteroatom-containing compounds have been explored as unnatural substrates. Considerable advances related to the search for efficient enzymatic systems able to support a broader substrate scope with high catalytic performance are described in the literature. These reports include mainly native and mutated enzymes and whole cells biocatalysis. Herein, we describe the historical background along with the progress of biocatalyzed reactions involving the heteroatom(S, Se, B, P and Si) from hetero-organic substrates.

Bioconversion of waste cooking oil glycerol from cabbage extract to lactic acid by Rhizopus microsporus

Abstract Glycerol from spent oil was processed by transesterification for biodiesel production. Although glycerol contains many types of impurities, it can be used as a C-source for lactic acid production by fungi, such as Rhizopus microsporus. In this study, we found that wild type R. microsporus (LTH23) produced more lactic acid than the mutant strains on cabbage glycerol media (CG media). More lactic acid was produced on CG media than on cabbage extract media (C media) by about two-fold in batch fermentation conditions. In addition, we found that lactic acid production in a fed-batch process was also slightly higher than in a batch process. To study the combined effects of pH, urea, and glycerol waste concentration on lactic acid production, a response surface methodology was used. The optimum pH, urea, and glycerol waste concentrations were pH 6.5, 3.75 g/L, and 17 g/L, respectively. The maximum lactic acid production predicted by this equation model was 4.03 g/L.

Uso da microextração por sorbente empacotado (MEPS) para preparo de amostras em análises toxicológicas envolvendo fármacos benzodiazepí­nico / Microextraction by packed sorbent (MEPS) for sample preparation in toxicological analyses involving benzodiazepines

A microextração por sorbente empacotado (MEPS) é uma técnica de preparo de amostras ainda pouco utilizada no âmbito da toxicologia, em que os mesmos princípios da extração em fase sólida convencional são adaptados para uma escala miniaturizada. As principais vantagens da técnica estão associadas ao pequeno volume de amostra e de solventes utilizados, à possibilidade de realizar múltiplas extrações com um mesmo cartucho e à facilidade de automação. Os benzodiazepínicos possuem grande relevância na toxicologia dada sua ampla utilização e seus efeitos que podem, por exemplo, comprometer a capacidade de dirigir, além do uso abusivo, e como drogas facilitadoras de crimes. Neste trabalho, um método de MEPS foi desenvolvido e otimizado para a determinação de sete benzodiazepínicos e seus produtos de biotransformação (diazepam, clonazepam, flunitrazepam, alprazolam, bromazepam, 7-aminoflunitrazepam e nordiazepam) utilizando 100 µL de amostra de sangue total post mortem. Após a extração, os eluatos foram analisados por cromatografia líquida em fase reversa acoplada a espectrometria de massas. O método foi validado de acordo com as recomendações do Scientific Working Group for Forensic Toxicology, apresentando linearidade adequada de 5 a 500 ng.mL-1 . Os valores de exatidão (90,4 a 109,5%), precisão intra-dia (2,5 a 10,7 %CV) e inter-dia (1,1 a 8,0 %CV) também foram satisfatórios. MEPS foi realizada mais de 60 vezes com a mesma fase extratora sem evidências de contaminação cruzada. Dez amostras reais fornecidas pelo Instituto Médico Legal de São Paulo foram analisadas. Foram quantificados diazepam, nordiazepam, clonazepam e bromazepam. Os resultados encontrados em cada uma das amostras foram comparados com dados da literatura

Microextraction by packed sorbent (MEPS) is a sample preparation technique still little used in toxicology, where the same principles of conventional solid phase extraction are adapted to a miniaturized scale. The main advantages of the technique are associated with the small volume of sample and solvents required, the possibility of performing multiple extractions with the same cartridge and ease process automation. Benzodiazepine drugs are relevant in toxicology because of their widespread use, and effects (which may, for example, compromise the ability to drive vehicles), abuse and records as crime-facilitating drugs. In this work, a MEPS method was developed and optimized for a determination of seven benzodiazepines and their metabolites (diazepam, nordiazepam, clonazepam, flunitrazepam, 7-aminoflunitrazepam, alprazolam, and bromazepam) using 100 µL of post mortem whole blood. After extraction, the eluates were analyzed by reversed-phase liquid chromatography coupled to mass spectrometry. The method was validated according to the recommendations of the Scientific Working Group for Forensic Toxicology, presenting adequate linearity from 5 to 500 ng.mL-1 . The values of accuracy (90.4 to 109.5%), intra-day precision (2.5 to 10.7 %CV) and inter-day (1.1 to 8.0 %CV) also presented satisfactory results. MEPS was performed more than 60 times with the same extractive phase without compromising the results with the evidence of carryover. Institute of Legal Medicine were submitted to analysis by MEPS-LC-MS/MS. In these samples, the following analytes were quantified: diazepam, nordiazepam, clonazepam and bromazepam. The results found in each of the samples were compared with data from the literature

Variation analysis of bacterial polyhydroxyalkanoates production using saturated and unsaturated hydrocarbons

ABSTRACT Polyhydroxyalkanoates (PHA) are efficient, renewable and environment friendly polymeric esters. These polymers are synthesized by a variety of microbes under stress conditions. This study was carried out to check the suitability of waste frying oil in comparison to other oils for economical bioplastic production. Six bacterial strains were isolated and identified as Bacillus cereus (KF270349), Klebsiella pneumoniae (KF270350), Bacillus subtilis (KF270351), Brevibacterium halotolerance (KF270352), Pseudomonas aeruginosa (KF270353), and Stenotrophomonas rhizoposid (KF270354) by ribotyping. All strains were PHA producers so were selected for PHA synthesis using four different carbon sources, i.e., waste frying oil, canola oil, diesel and glucose. Extraction of PHA was carried out using sodium hypochlorite method and maximum amount was detected after 72 h in all cases. P. aeruginosa led to maximum PHA production after 72 h at 37 °C and 100 rpm using waste frying oil that was 53.2% PHA in comparison with glucose 37.8% and cooking oil 34.4%. B. cereus produced 40% PHA using glucose as carbon source which was high when compared against other strains. A significantly lesser amount of PHA was recorded with diesel as a carbon source for all strains. Sharp Infrared peaks around 1740-1750 cm-1 were present in Fourier Transform Infrared spectra that correspond to exact position for PHA. The use of waste oils and production of poly-3hydroxybutyrate-co-3hydroxyvalerate (3HB-co-3HV) by strains used in this study is a good aspect to consider for future prospects as this type of polymer has better properties as compared to PHBs.

Asymmetric bioreduction of ketoesters derivatives by Kluyveromyces marxianus: influence of molecular structure on the conversion and enantiomeric excess

ABSTRACT This study presents the bioreduction of six β-ketoesters by whole cells of Kluyveromyces marxianus and molecular investigation of a series of 13 β-ketoesters by hologram quantitative structure-activity relationship (HQSAR) in order to relate with conversion and enantiomeric excess of β-stereogenic-hydroxyesters obtained by the same methodology. Four of these were obtained as (R)-configuration and two (S)-configuration, among them four compounds exhibited >99% enantiomeric excess. The β-ketoesters series LUMO maps showed that the β-carbon of the ketoester scaffold are exposed to undergo nucleophilic attack, suggesting a more favorable β-carbon side to enzymatic reduction based on adopted molecular conformation at the reaction moment. The HQSAR method was performed on the β-ketoesters derivatives separating them into those provided predominantly (R)- or (S)-β-hydroxyesters. The HQSAR models for both (R)- and (S)-configuration showed high predictive capacity. The HQSAR contribution maps suggest the importance of β-ketoesters scaffold as well as the substituents attached therein to asymmetric reduction, showing a possible influence of the ester group carbonyl position on the molecular conformation in the enzyme catalytic site, exposing a β-carbon side to the bioconversion to (S)- and (R)-enantiomers.

Bioremediation of polycyclic aromatic hydrocarbon (PAH) compounds: (acenaphthene and fluorene) in water using indigenous bacterial species isolated from the Diep and Plankenburg rivers, Western Cape, South Africa

Abstract This study was conducted to investigate the occurrence of PAH degrading microorganisms in two river systems in the Western Cape, South Africa and their ability to degrade two PAH compounds: acenaphthene and fluorene. A total of 19 bacterial isolates were obtained from the Diep and Plankenburg rivers among which four were identified as acenaphthene and fluorene degrading isolates. In simulated batch scale experiments, the optimum temperature for efficient degradation of both compounds was determined in a shaking incubator after 14 days, testing at 25 °C, 30 °C, 35 °C, 37 °C, 38 °C, 40 °C and 45 °C followed by experiments in a Stirred Tank Bioreactor using optimum temperature profiles from the batch experiment results. All experiments were run without the addition of supplements, bulking agents, biosurfactants or any other form of biostimulants. Results showed that Raoultella ornithinolytica, Serratia marcescens, Bacillus megaterium and Aeromonas hydrophila efficiently degraded both compounds at 37 °C, 37 °C, 30 °C and 35 °C respectively. The degradation of fluorene was more efficient and rapid compared to that of acenaphthene and degradation at Stirred Tank Bioreactor scale was more efficient for all treatments. Raoultella ornithinolytica, Serratia marcescens, Bacillus megaterium and Aeromonas hydrophila degraded a mean total of 98.60%, 95.70%, 90.20% and 99.90% acenaphthene, respectively and 99.90%, 97.90%, 98.40% and 99.50% fluorene, respectively. The PAH degrading microorganisms isolated during this study significantly reduced the concentrations of acenaphthene and fluorene and may be used on a larger, commercial scale to bioremediate PAH contaminated river systems.

Phenol degradation and genotypic analysis of dioxygenase genes in bacteria isolated from sediments

Abstract The aerobic degradation of aromatic compounds by bacteria is performed by dioxygenases. To show some characteristic patterns of the dioxygenase genotype and its degradation specificities, twenty-nine gram-negative bacterial cultures were obtained from sediment contaminated with phenolic compounds in Wuhan, China. The isolates were phylogenetically diverse and belonged to 10 genera. All 29 gram-negative bacteria were able to utilize phenol, m-dihydroxybenzene and 2-hydroxybenzoic acid as the sole carbon sources, and members of the three primary genera Pseudomonas, Acinetobacter and Alcaligenes were able to grow in the presence of multiple monoaromatic compounds. PCR and DNA sequence analysis were used to detect dioxygenase genes coding for catechol 1,2-dioxygenase, catechol 2,3-dioxygenase and protocatechuate 3,4-dioxygenase. The results showed that there are 4 genotypes; most strains are either PNP (catechol 1,2-dioxygenase gene is positive, catechol 2,3-dioxygenase gene is negative, protocatechuate 3,4-dioxygenase gene is positive) or PNN (catechol 1,2-dioxygenase gene is positive, catechol 2,3-dioxygenase gene is negative, protocatechuate 3,4-dioxygenase gene is negative). The strains with two dioxygenase genes can usually grow on many more aromatic compounds than strains with one dioxygenase gene. Degradation experiments using a mixed culture representing four bacterial genotypes resulted in the rapid degradation of phenol. Determinations of substrate utilization and phenol degradation revealed their affiliations through dioxygenase genotype data.