Extracellular serine proteases by Acremonium sp. L1-4B isolated from Antarctica: Overproduction using cactus pear extract with response surface methodology

• Autor(a) principal: Evaristo da Silva Nascimento, Talita Camila
• Data de Publicação: 2015
• Outros Autores: Sena, Amanda Reges de, Galindo Gomes, Jose Erick [UNESP], Santos, Wellington Leal dos, Agamez Montalvo, Gualberto Segundo, Tambourgi, Elias Basile, Medeiros, Erika Valente de, Sette, Lara Duraes [UNESP], Pessoa Junior, Adalberto, Moreira, Keila Aparecida
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://dx.doi.org/10.1016/j.bcab.2015.10.006; http://hdl.handle.net/11449/165053
• topic: Filamentous fungus; Psychrophilic microorganisms; Cactus; Optimization; Bioconversion

Acremonium sp. L1-4B isolated from lichen in Antarctica was used to produce extracellular proteases through submerged fermentation using cactus pear extract (Opuntia ficus-indica Mill.). A 2(3) factorial design was applied to optimize the protease production using three independent variables, namely temperature, pH and concentration of yeast extract, was also used a Central Composite Design (CCD) under Response Surface Methodology (RSM). All variables and interactions analyzed in the factorial design were significant or marginally significant, a Central Composite Design was developed, and the Response Surface Methodology towards the highest point it was established. The experimental model was validated under 14 degrees C, pH 7.54, and 0.55% yeast extract, showing a protease activity of 447.65 +/- 2.6 U/mL by a prediction model of 445.48 U/mL. The enzyme showed a molecular weight of 59 kDa; it was inhibited in the presence of PMSF (serine protease); it presented optimal conditions at pH 8.0 and 50 degrees C; it remained stable at pH in the 3.0-9.0 range and between 10 and 40 degrees C; it showed a tolerance to 3000 mM NaCl as well as to surfactants, hydrogen peroxide and urea at 5%. This paper presents a proposal for an economically attractive production methodology using cactus pear as a primary source of carbon. In addition, the protease secreted by Acremonium sp. L1-4B presented a combination of biochemical characteristics that grants a promising variability of biotechnological applications. (C) 2015 Elsevier Ltd. All rights reserved.