RESUMEN
BACKGROUND: Lipases are extensively exploited in lots of industrial fields; cold-adapted lipases with alkali-resistance are especially desired in detergent industry. Penicillium cyclopium lipase I (PCL) might be suitable for applications of detergent industry due to its high catalytic efficiency at low temperature and relatively good alkali stability. In this study, to better meet the requirements, the alkali stability of PCL was further improved via directed evolution with error-prone PCR. RESULTS: The mutant PCL (N157F) with an improved alkali stability was selected based on a high-throughput activity assay. After incubating at pH 11.0 for 120 min, N157F retained 70% of its initial activity, which was 23% higher than that of wild type PCL. Combined with the three-dimensional structure analysis, N157F exhibited an improved alkali stability under the high pH condition due to the interactions of hydrophilicity and ß-strand propensity. Conclusions: This work provided the theoretical foundation and preliminary data for improving alkali stability of PCL to meet the industrial requirements, which is also beneficial to improving alkali-tolerance ability of other industrial enzymes via molecular modification.
Asunto(s)
Penicillium/enzimología , Estabilidad de Enzimas , Industria de Detergentes , Lipasa/metabolismo , Penicillium/aislamiento & purificación , Penicillium/genética , Reacción en Cadena de la Polimerasa/métodos , Frío , Álcalis , Biocatálisis , Interacciones Hidrofóbicas e Hidrofílicas , Concentración de Iones de Hidrógeno , Lipasa/aislamiento & purificación , Lipasa/genética , MutaciónRESUMEN
Detergentes e seus congêneres são produtos destinados à limpeza e higienização de objetos inanimados e/ou ambientes. As empresas que produzem ou importam os produtos mencionados devem cumprir as Boas Práticas de Fabricação e Controle, com a finalidade de garantir a qualidade e a segurança de uso destes produtos. Este estudo teve por objetivo avaliar a qualidade microbiológica de detergentes e seus congêneres. Cento e quatro amostras foram analisadas no período entre Abril de 2001 e Outubro de 2002, sendo que 41 por cento das amostras analisadas apresentaram crescimento microbiano.