Full use of residues from industrial processes is a fundamental necessity of contemporary society, since it avoids impacts to the environment by using residues as inputs for other products of high economic and social ...Full use of residues from industrial processes is a fundamental necessity of contemporary society, since it avoids impacts to the environment by using residues as inputs for other products of high economic and social importance. In this study, lipase production of the crude enzymatic extracts obtained by Aspergillus niger using cassava peel as substrate and sunflower oil as an inductor was investigated. The optimized cultivation temperature and concentration of inductor were determined using the response surface methodology. The two variables studied exercised influence in the production of lipase in the 95% level of confidence. The response surface obtained indicated that the conditions that maximize lipase activity production were 30.5 ~C and initial concentration of sunflower oil was 2.5% （w/w）. Through this analysis, it is evident that extremes in temperature and concentration of inductor tend to decrease lipase production, since low temperatures decrease metabolism and high temperatures may inactivate the lipase. Optimum lipase yield was 59.8 U/g of dry peel which was fermented for 60 h. Lipase production presents a peak of 61.3 U/g, at 72 h of fermentation. However, this value is statistically equal （p 〉 0.05） of the value of lipase activity obtained for 60 h and 84 h of fermentation.展开更多
文摘Full use of residues from industrial processes is a fundamental necessity of contemporary society, since it avoids impacts to the environment by using residues as inputs for other products of high economic and social importance. In this study, lipase production of the crude enzymatic extracts obtained by Aspergillus niger using cassava peel as substrate and sunflower oil as an inductor was investigated. The optimized cultivation temperature and concentration of inductor were determined using the response surface methodology. The two variables studied exercised influence in the production of lipase in the 95% level of confidence. The response surface obtained indicated that the conditions that maximize lipase activity production were 30.5 ~C and initial concentration of sunflower oil was 2.5% （w/w）. Through this analysis, it is evident that extremes in temperature and concentration of inductor tend to decrease lipase production, since low temperatures decrease metabolism and high temperatures may inactivate the lipase. Optimum lipase yield was 59.8 U/g of dry peel which was fermented for 60 h. Lipase production presents a peak of 61.3 U/g, at 72 h of fermentation. However, this value is statistically equal （p 〉 0.05） of the value of lipase activity obtained for 60 h and 84 h of fermentation.
