Use of agro-industrial residues for lipase production by Candida viswanathii in a solid-state cultivation system

Abstract

Lipases are an important group of enzymes that catalyze the hydrolysis of triacylglycerol and there are many industrial applications. The aim of this work was to produce the lipase by the yeast Candida viswanathii using solid state culture with agro-industrial wastes (barley bagasse, corn husk, corncob, soybean seed coat and soybean husk). The biomass pretreatment methods were evaluated, as well as the media supplementation with nitrogen and mixing substrates. Also, the efficiency of olive oil and poultry fat was evaluated on the induction of lipase production, followed by the scale-up from 20 g to 100 g. The enzyme activities in the cultures without pretreatement were higher when soybean seed coat supplemented with both olive oil (7.06 U/gss) and poultry fat (8.40 U/gss) were used. However, the pretreated substrates did not demonstrate a satisfying induction of lipolytic activity. From the nitrogen sources, yeast extract showed an increase of approximately twice the original production with both olive oil (18.12 U/gss) and poultry fat (15.98 U/gss) supplementation. On the scale-up step, the results demonstrated that, for the 20 g culture, the best lipase production was observed on the 7^th day (33.52 U/gss), while for the 100 g culture the highest lipase activity was after 5 days (17.88 U/gss). The cultivation of ground soybean skin without pretreatment supplemented with yeast extract as a source of nitrogen, with fresh barley bagasse and poultry fat was the best combination.