The performance of microbial lipase immobilized onto polyolefin supports for hydrolysis of high oleate sunflower oil

Abstract

The application of immobilized microbial lipase for the catalytic hydrolysis of triglyceride esters is described. Sunflower oil was used as the primary substrate for the hydrolysis in the presence of microbial lipase extracted from the fungal yeast Candida rugosa OF360. Lipase was immobilized onto three different polyolefin supports: high density polypropylene (Accurel EG100 and EP100), and low density polyethylene (Accurel EP400). In the case of Accurel EP400 there was a strong positive linear relationship between enzyme concentration prior to immobilization and expressed enzyme activity. In contrast, Accurel EG100 exhibited no increase in expressed activity with increasing initial enzyme concentration. The presence of glutaraldehyde crosslinking agent resulted in enhanced expressed activity on EP100 and exhibited minimal change in EP400. Maximum immobilized efficiency was observed for the Accurel EP100 and EP400 at particle sizes in the 200 μm range. Overall, half-lives of immobilized enzyme were observed to be up to sevenfold that of enzyme in free solutions. Optimum pH values in the range 7–9 were confirmed. Optimum temperatures for expressed activity of lipase on the Accurel EP100 and EP400 were determined to be 30 °C and 45 °C respectively.