RESUMO
A novel tri-substrate fermentation (TSF) process was developed for the production of lipase from Aspergillus niger MTCC 2594 using agro-industrial residues, wheat bran (WB), coconut oil cake (COC) and an agro-product, wheat rawa (WR). The lipase activity was 628.7+/-13 U/g dry substrate (U/gds) at 30 degrees C and 96 h and growth studies indicated that addition of WR significantly augmented the biomass and lipase production. Scale up of lipase production at 100g and 3 kg (3 x 1 kg) tray-level batch fermentation resulted in 96% and 83.0% of enzyme activities, respectively, at 72 h. Maximum activity of 745.7+/-11U/gds was obtained, when fermented substrate was extracted in buffer containing 1% (w/v) sodium chloride and 0.5% (w/v) Triton X-100. Furthermore, the direct application of fermented substrate for tallow hydrolysis makes the process economical for industrial production of biofuel.
Assuntos
Aspergillus niger/enzimologia , Gorduras/metabolismo , Fermentação , Lipase/biossíntese , Biomassa , Hidrólise , Especificidade por SubstratoRESUMO
Corn steep liquor (CSL) has been used as a nutrition adjunct for the production of an extracellular lipase from Aspergillus niger, which has immense importance as an additive in laundry detergent formulations. A five-level four-factorial central composite design was chosen to determine the optimal medium components with four critical variables, namely, CSL, NH4H2PO4, Na2HPO4, and sesame oil, that were found to be influential for lipase production by the classical one-factor-at-a-time method. The model suggested that all of the factors chosen had a significant impact on lipase production, and the optimum values of the influential parameters were CSL, 2.0%, w/v; NH4H2PO4, 0.05%, w/v; Na2HPO4, 0.75%, w/v; and sesame oil, 2.0%, w/v, with an activity of 26.7 U/mL at 48 h and 30 degrees C, which was 2.16-fold higher than the initial activity (12 U/mL) obtained by the conventional one-factor-at-a-time method. Furthermore, the enzyme has good potential for the hydrolysis of vegetable oils and fish oils, and a hydrolytic ratio of 88.73% was obtained with palm oil at 48 h. The utilization of CSL and sesame oil for lipase production from A. niger makes the process green, because both are renewable substrates and economically viable at an industrial scale.
Assuntos
Aspergillus niger/enzimologia , Resíduos Industriais , Lipase/biossíntese , Lipase/metabolismo , Óleos/metabolismo , Zea mays , Aspergillus niger/crescimento & desenvolvimento , Detergentes/análise , Óleos de Peixe/metabolismo , Hidrólise , Óleos de Plantas/metabolismo , Óleo de GergelimRESUMO
The efficacy of lipase from Aspergillus niger MTCC 2594 as an additive in laundry detergent formulations was assessed using response surface methodology (RSM). A five-level four-factorial central composite design was chosen to explain the washing protocol with four critical factors, viz. detergent concentration, lipase concentration, buffer pH and washing temperature. The model suggested that all the factors chosen had a significant impact on oil removal and the optimal conditions for the removal of olive oil from cotton fabric were 1.0% detergent, 75 U of lipase, buffer pH of 9.5 and washing temperature of 25 degrees C. Under optimal conditions, the removal of olive oil from cotton fabric was 33 and 17.1% at 25 and 49 degrees C, respectively, in the presence of lipase over treatment with detergent alone. Hence, lipase from A. niger could be effectively used as an additive in detergent formulation for the removal of triglyceride soil both in cold and warm wash conditions.