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
The interest for lipase production is due to the ability of this enzyme to catalyze some reactions, such as the transesterification. Although industrial biodiesel is produced chemically, there are several problems ass...The interest for lipase production is due to the ability of this enzyme to catalyze some reactions, such as the transesterification. Although industrial biodiesel is produced chemically, there are several problems associated with this technology that can be prevented through the use of lipases. The present work aimed to select microorganisms with potential for production of lipase with transesterification activity. The lipase from Burkholderia cepacia was the one with the most promising results for this type of reaction, showing results of hydrolytic activity at 37 ℃and pH 8.0. The pH and volume of crude enzyme extract that showed favorable for synthesis ofbiodiesel is at about pH 6.0 and 3.75 mL, respectively, which represents approximately 42% of water in the system, ensuring the conversion of nearly 60% to biodiesel.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.
文摘The interest for lipase production is due to the ability of this enzyme to catalyze some reactions, such as the transesterification. Although industrial biodiesel is produced chemically, there are several problems associated with this technology that can be prevented through the use of lipases. The present work aimed to select microorganisms with potential for production of lipase with transesterification activity. The lipase from Burkholderia cepacia was the one with the most promising results for this type of reaction, showing results of hydrolytic activity at 37 ℃and pH 8.0. The pH and volume of crude enzyme extract that showed favorable for synthesis ofbiodiesel is at about pH 6.0 and 3.75 mL, respectively, which represents approximately 42% of water in the system, ensuring the conversion of nearly 60% to biodiesel.
