Aproveitamento de subprodutos agroindustriais para produção de lipase por fermentação em estado sólido pela linhagem mutante Aspergillus niger 11T53A14

• Autor(a) principal: Veloso, Elizabeth Cristina Tavares
• Data de Publicação: 2018
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UERJ
• Texto Completo: http://www.bdtd.uerj.br/handle/1/12078
• topic: Solid state fermentation; agroindustrial by products utilization; aspergillus niger; lipase; Fermentação em estado sólido; aproveitamento de subprodutos agroindustriais; aspergillus niger; lipase; CNPQ::ENGENHARIAS::ENGENHARIA QUIMICA::PROCESSOS INDUSTRIAIS DE ENGENHARIA QUIMICA

This work aimed at defining the best conditions of microbial lipase production by A. niger 11T53A14 mutant strain by solid state fermentation using different agroindustrial byproducts (coffee grounds, macaúba pulp and mango kernel). The fermentation was carried out in a 250 mL erlenmeyer flask containing 15 g of substrate inoculated with 107 spores/mL. Experiments were conducted at 32 oC for 48 hours, following a 25-1 fractionated factorial design. The process variables were solution of HCl 0.1M, nitrogen (% ammonium sulfate) and concentration of coffee grounds, macaúba pulp and mango kernel. The best lipase activity (81.16 U/g) was obtained with 80 mL/100 g HCl 0.1M solution, ammonium sulfate (0.4%) and coffee grounds (11%). Based on the results, the central composite rotatable design was carried out. In this case, three independent variables were studied: percentage of nitrogen (ammonium sulfate), volume of solution of HCl 0.1 M and coffee grounds. The highest lipase activity (120.6 U/g ) was obtained with 0.6% nitrogen (ammonium sulfate), 3.32% of coffee grounds and 90 mL of HCl solution. The screening showed: nitrogen and the volume of HCl solution had positive effect on lipase production. Therefore, the influence of the volume of HCl solution (110 and 140 mL) and the increase of ammonium sulfate (1%) were tested. The highest lipase activity (130.5 U/g) was observed with 110 mL of solution of HCl 0.1 M. The increase in the percentage of nitrogen to 1% did not favor lipase synthesis. Different sources of nitrogen (sodium nitrate, ammonium nitrate and urea) and inoculum concentration (106, 107 and 108 spores/mL) were evaluated. In this study the best source of nitrogen was ammonium sulfate and the concentration of inoculum 107 spores/mL. A kinetic study showed that the lipase production occurred with highest lipase activity (148.4 U/g) with 36 hours of fermentation and with productivity of 4.12 U/g.h. Lipase showed higher activity value at pH 6 (115.53 U/g) and temperature at 30oC (144.23 U/g). Therefore, the results obtained in this work were superior to those found in the literature, since maximum lipase activity was obtained in a short fermentation time, favoring this increase production on a large scale. The use of coffee grounds has shown that this byproduct can be used as renewable raw material for lipase production