Production characterization and Immobilization of fungal lipase produced Using soybean husk as a substrate

Abstract

The lipases class of enzymes also known as triacylglycerol hydrolases are a class of industrially important enzyme groups of hydrolases. The versatility of this group of enzymes lies in their ability to work in various conditions found in industries such as extreme profiles of temperature, pH and presence of organic or aqueous solvents conditions. The filamentous fungi were found suitable to ferment agricultural waste into valuable products such as enzymes. In this study, the isolation and identification of the native strain for the production of lipase utilizing soybean husk though solid-state formation (SSF) and submerged fermentation (SmF) were carried out. Optimization for the SSF has been carried out by Response Surface Methodology (RSM). The partial purification and characterization of isolated enzymes were also performed in this study. A comparative assessment of two enzyme immobilization techniques, namely sol-gel and cross-linked enzyme crystal (CLEC) on enzyme activity was also performed. newlineThe fungal strain, Aspergillus sydowii JPG01 was isolated from sewage treatment plant compost heaps of JUET, Guna, India. It was observed that the Aspergillus sydowii JPG01 found to be a potential lipase producer and soybean-husk is an ideal substrate for lipase activity. The results indicate that as an inducer coconut oil and soybean oil give the highest lipase activity of 57.09 U/gds and 55.09 U/gds respectively at a concentration of 10%. The ideal incubation temperature, pH and incubation time found to be 37oC, 8 and 72 hours respectively. Further, on partial purification by (NH4)2SO4, precipitation followed by dialysis, a 2.74-fold purification was achieved by 90% (NH4)2SO4 and precipitation with ~24.59% yield. The characterization indicates that the enzyme retained its catalytic activity ~100% between temperature 20-40oC for 1 hour. The optimum pH for enzyme activity is 8 however, after 1-hour incubation; it also retained its activity up to 38% at pH 11. As per the Lineweaver-Burk plot, at optimum conditions by using pNPP as substrate, the Km and Vmax were observed 34.495 µmole and 3378.378 µmole/min respectively. It suggests that this lipase qualifies to fulfil all criteria for the true lipase. The particle size of standard sieve number 85 was best suitable in both SSF and SmF of fermentations. newline newline