Selection and optimization of extracellular lipase production using agro-industrial waste

The aim of this study was to isolate and select lipase-producing microorganisms originated from different substrates, as well as to optimize the production of microbial lipase by submerged fermentation under different nutrient conditions. Of the 40 microorganisms isolated, 39 showed a halo around the colonies and 4 were selected (Burkholderia, Bacillus sp., Penicillium lanosum and Corynebac glutamyl), where strains showing lipolytic halo Radius (R) / colony radius (r) ratio greater than 2.0 were selected. The results of submerged fermentation expressed as enzymatic activity revealed that the genera of microorganisms significantly influenced the enzymatic reaction, and lipase obtained from Burkholderia cepacia was the most promising, with activity of 0.0058 U.mL-1. It was also observed in the optimization step of lipase production that the sodium nitrate content (NaNO3) had a positive effect on enzyme production, and its increase was indicative of higher enzymatic activity. The addition of sources of organic nitrogen (corn steep liquor, p = 0.2398), carbon (soybean oil, p = 0.3379), magnesium MgSO4.7H2O (p = 0.4189) and potassium KH2PO4 (p = 0.8562) had no significant effects on the lipase production and could result in decreased production of extracellular lipases.Keywords: Burkholderia cepacia, hydrolytic enzymes, residue, submerged fermentationAfrican Journal of Biotechnology, Vol. 13(4), pp. 566-573, 22 January, 201

Viabilidade econômica da implantação de um sistema de coleta e secagem

O objetivo deste trabalho foi estudar a viabilidade econômica da implantação de um sistema de coleta e secagem da polpa residual de lavagem de batatas na linha de processamento de batatas fritas, para ser utilizada em snacks fritos, visando o aproveitamento de resíduos agroindustriais, como novo ingrediente para a indústria de alimentos. O método payback foi estudado, este é um método de avaliação direto, no qual calcula-se o número de anos que decorrerão até que os fluxos de caixa acumulados igualem ao montante do investimento inicial. De acordo com os resultados obtidos, a empresa irá economizar 19,8 % de farinha de trigo mensalmente, com a substituição da farinha de trigo por polpa residual de lavagem da batata desidratada (PRLBD), no processamento de snacks fritos. O payback para a compra e implantação do sistema de secagem da PRLBD será pago em aproximadamente 16 meses. Este estudo demonstrou que o projeto é viável do ponto de vista econômico, além de contribuir na diminuição do impacto ambiental e com sustentabilidade da empresa, proporcionando um destino adequado para os resíduos agroindustriais

Análise da eficácia do uso terapêutico da trimetazidina nas principais síndromes coronarianas agudas

A injúria de reperfusão, ou isquemia, é um mecanismo fisiopatológico que ocorre nas etiopatogenias do miocárdio, como na angina instável. Assim, são utilizados fármacos adjuvantes citoprotetores, como a trimetazidina (TMZ), que visam à diminuição do tempo de hospitalização e melhora na função cardíaca com ação profilática contra essa lesão. No entanto, apesar dos seus potenciais benefícios no tratamento da síndrome coronariana aguda, ainda não está clara a sua eficácia em relação a outras terapias disponíveis. Nesse sentido, o objetivo do estudo é analisar a eficácia do uso terapêutico da trimetazidina nas principais síndromes coronarianas agudas. Foi realizada uma revisão sistemática usando as bases de dados PubMed, Cochrane Library e Embase. Um total de 3 estudos foi incluído na análise. Os resultados mostraram que a terapia com trimetazidina reduziu significativamente a incidência de eventos cardíacos adversos maiores (ECAM) (OR = 0,33, IC 95% 0,15-0,75, p = 0,007), menor dano miocárdico (p < 0,05) e fração de ejeção ventricular esquerda mais elevada e menos eventos adversos em comparação com o grupo placebo (p < 0,05). Não foram observadas diferenças significativas entre os grupos de trimetazidina e controle em termos de mortalidade por todas as causas, mortalidade cardiovascular ou incidência de eventos adversos. Os resultados deste estudo sugerem que a terapia adjuvante com trimetazidina pode melhorar os resultados clínicos e a função cardíaca em pacientes com IAM sem aumentar o risco de eventos adversos. No entanto, são necessários mais ensaios clínicos randomizados em larga escala para confirmar esses resultados e determinar a duração e dose ideais da terapia com trimetazidina nessa população de pacientes

Study of ozone/activated carbon process for the removal of phthalates in aqueous phase

Le respect des normes de rejets aqueux industriels imposées par la directive cadre sur l’eau (échéances en 2021) concernant les micropolluants, et notamment les phtalates, nécessite la mise au point de procédés de traitement innovants. L’étude du procédé basé sur le couplage ozone/charbon actif a ainsi été effectuée. Après la détermination des propriétés chimiques et texturales des charbons actifs testés, l’efficacité de ce couplage pour l’élimination des phtalates a été éprouvée selon plusieurs critères : cinétique d’élimination des polluants cibles, évolution de la minéralisation et de la toxicité au cours du traitement. La comparaison des résultats obtenus avec ceux de méthodes classiques (ozonation et adsorption seules) a mis en évidence le fort potentiel du couplage ozone/charbon actif, qui permet d’obtenir une élimination rapide des polluants ainsi qu’une minéralisation et une détoxification avancées dans toutes les conditions expérimentales testées. Ce couplage c’est aussi révélé efficace lors du traitement de matrices plus complexes, telle qu’une eau de sortie de station d’épuration. En outre, cette étude a permis de déterminer les propriétés chimiques et texturales du charbon actif favorisant ce procédé. Il a aussi été montré que ce matériau joue un rôle d’initiateur et de promoteur de radicaux libres (les réactions sont très majoritairement de nature radicalaire) ainsi que de support réactionnel. Enfin, cette étude a montré qu’une régénération in situ du matériau, économiquement très intéressante, pourrait être obtenue au cours du traitement.In order to comply with the standards governing the discharge of industrial effluents (Water Framework Directive, target date 2021) concerning micropollutants, in particular phthalates, innovative wastewater treatment processes have to be used. The present research addresses this issue through a study of ozone/activated carbon coupling. After determining the textural and chemical properties of several activated carbons, the efficiency of this coupling for the removal of phthalates was tested according to the following criteria: degradation kinetics of the target pollutants and evolution of both toxicity and mineralization during the process. Compared to the classical methods (ozonation or adsorption used separately), coupling proved to be highly efficient. It enables the fast removal of pollutants with a significant decrease in mineralization and toxicity. Coupling also proved to be efficient for the treatment of more complex matrices such as municipal wastewater treatment outflow. Moreover, the activated carbon properties which favour the process have also been determined. It is shown that, in this coupling, the material acts as a radical initiator and promoter (the reactions are mainly radical in nature) and as a reaction support. Lastly, the study also shows that in situ regeneration of the activated carbon, which would be economically attractive, could be achieved during the process

Etude d'un procédé de dépollution basé sur le couplage ozone/charbon actif pour l'élimination des phtalates en phase aqueuse

In order to comply with the standards governing the discharge of industrial effluents (Water Framework Directive, target date 2021) concerning micropollutants, in particular phthalates, innovative wastewater treatment processes have to be used. The present research addresses this issue through a study of ozone/activated carbon coupling. After determining the textural and chemical properties of several activated carbons, the efficiency of this coupling for the removal of phthalates was tested according to the following criteria: degradation kinetics of the target pollutants and evolution of both toxicity and mineralization during the process. Compared to the classical methods (ozonation or adsorption used separately), coupling proved to be highly efficient. It enables the fast removal of pollutants with a significant decrease in mineralization and toxicity. Coupling also proved to be efficient for the treatment of more complex matrices such as municipal wastewater treatment outflow. Moreover, the activated carbon properties which favour the process have also been determined. It is shown that, in this coupling, the material acts as a radical initiator and promoter (the reactions are mainly radical in nature) and as a reaction support. Lastly, the study also shows that in situ regeneration of the activated carbon, which would be economically attractive, could be achieved during the process.Le respect des normes de rejets aqueux industriels imposées par la directive cadre sur l’eau (échéances en 2021) concernant les micropolluants, et notamment les phtalates, nécessite la mise au point de procédés de traitement innovants. L’étude du procédé basé sur le couplage ozone/charbon actif a ainsi été effectuée. Après la détermination des propriétés chimiques et texturales des charbons actifs testés, l’efficacité de ce couplage pour l’élimination des phtalates a été éprouvée selon plusieurs critères : cinétique d’élimination des polluants cibles, évolution de la minéralisation et de la toxicité au cours du traitement. La comparaison des résultats obtenus avec ceux de méthodes classiques (ozonation et adsorption seules) a mis en évidence le fort potentiel du couplage ozone/charbon actif, qui permet d’obtenir une élimination rapide des polluants ainsi qu’une minéralisation et une détoxification avancées dans toutes les conditions expérimentales testées. Ce couplage c’est aussi révélé efficace lors du traitement de matrices plus complexes, telle qu’une eau de sortie de station d’épuration. En outre, cette étude a permis de déterminer les propriétés chimiques et texturales du charbon actif favorisant ce procédé. Il a aussi été montré que ce matériau joue un rôle d’initiateur et de promoteur de radicaux libres (les réactions sont très majoritairement de nature radicalaire) ainsi que de support réactionnel. Enfin, cette étude a montré qu’une régénération in situ du matériau, économiquement très intéressante, pourrait être obtenue au cours du traitement

Degradation kinetics of DEP in water by ozone/activated carbon process: Influence of pH

International audienceEfficiency of the ozone (O$_3$)/Activated Carbon (AC) process to remove phthalates was studied by investigating the degradation kinetics of diethylphthalate (DEP) chosen as model pollutant. The influence of pH was determined by performing experiments at five pH values (2.5 < pH < 7.2). The kinetic contribution of radical mechanisms (δ$^{HO•}$) was estimated by using a radical scavenger (tert-butyl alcohol). Single ozonation of DEP was first performed. Pseudo-first order modelling shows that the reaction depends on pH, with kinetic constants varying from 0.0036 min$^{−1}$ (pH = 2.5) to 0.6129 min$^{− }$1 (pH = 7.2). Ozonation was then performed in the presence of a commercial AC (Pica L27), whose chemical and textural properties had been previously determined. Pseudo-first-order modelling shows a significant increase in DEP degradation kinetics: kinetic constants rose from 0.290 min$^{−1}$ (pH = 2.5) to 0.866 min$^{−1}$ (pH = 7.2). Estimation of the kinetic contribution of heterogeneous reactions to DEP removal (δ$^{hetero}$) shows that in acidic conditions, reactions are essentially located on the AC surface (δ$^{hetero}$ = 98.7% at pH = 2.5) and occur in the bulk liquid when pH increases (δ$^{hetero}$ = 29.2% at pH = 7.5). Lastly, estimation of the kinetic contribution of radical mechanisms (δ$^{HO•}$) shows that the increase in the DEP degradation kinetics is mainly due to radical reactions, with δ$^{HO•}$ increasing from 87.9% (pH = 2.5) to 92.0% (pH = 7.5). These radical reactions may be promoted by deprotonated acid groups present on the AC surface

Removal of a mix of endocrine disrupters from different natural matrices by ozone/activated carbon coupling process

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