Production of lipase extrated from aqueous waste: enzymatic activity kinetics

Abstract

Lipases are an important group of enzymes with various applications in the food, chemical and pharmaceutical industry, besides having great interest for the treatment of effluents with high lipid content. The objective of this study was to isolate, characterize and select lipolytic bacteria that produce lipase from aqueous waste effluents and to study the enzymatic activity kinetics of the extract obtained via submerged fermentation. The results obtained are promising, being possible to isolate and characterize 23 lipase-producing microorganisms, mostly gram-positive bacteria, but after the fermentation step in a liquid medium, gram negative bacteria showed the highest enzymatic activity (56.72 U.L -1 for STP 2A` bacterium and 81.99 U.L -1 for R2B). In the enzymatic activity kinetic study with the selected bacterium (R2B), among the six variables (temperature, pH, minimal mineral medium, soybean oil, glucose and sodium nitrate), temperature was the one that most positively influenced the enzymatic activity, and the best results were obtained at 40°C. It was concluded that the enzyme extract obtained from environmental waste may be used to treat the effluent and contribute to reduce environmental impacts.Index terms: Microbial extract, effluent treatment, sustainability. RESUMOAs lipases são um importante grupo de enzimas com diversas aplicações na indústria alimentar, química e farmacêutica, além de ter grande interesse para o tratamento de efluentes com alto teor de lipídios. Objetivou-se, neste trabalho, isolar, caracterizar e selecionar bactérias lipolíticas produtoras de lipase, a partir de efluentes residuais aquosos, assim como estudar a cinética da atividade enzimática do extrato obtido via fermentação submersa. Os resultados obtidos foram promissores, sendo possível isolar e caracterizar 23 microrganismos potencialmente produtores de lipase, sendo a maioria das bactérias Gram Positivas, porém após a etapa de fermentação em meio líquido, os Gram Negativos apresentaram as maiores atividades enzimáticas (56,72 U.L -1 para a bactéria ETE 2A` e 81,99 U.L -1 para a R2B). No estudo cinético da atividade enzimática com a bactéria selecionada (R2B), das seis variáveis (temperatura, pH, meio mínimo mineral, óleo de soja, glicose, e nitrato de sódio), a temperatura foi a que mais influenciou na atividade enzimática, tendo efeito positivo, e os melhores resultados foram obtidos a 40 °C. Concluiu-se que o extrato enzimático obtido, a partir de resíduos ambientais, poderão ser utilizados no próprio tratamento do efluente e contribuir na redução dos impactos ambientais.Termos para indexação: Extrato microbiano, tratamento de efluentes, sustentabilidade.

Evaluation of factors affecting the fungal lipase production using one factor at a time approach and response surface methodology

“…Willerding et al (2011) observed that among 181 strains, 75 strains (41%) were found to have high ability for lipase production up to 72 hours of incubation period. Whereas, Oliveira et al (2014) collected 23 lipolytic isolates from different sources; 7 isolates taken from residential grease trap, and 16 isolated from sewage treatment plant. Lipase activity for the potent one was 81.99 U/L…”