Abstract
Lipases (triacylglycerol ester hydrolases, E.C. 3.1.1.3) are very important enzymes, mainly in an underexploited lipid technology and bioindustry, and have emerged as one of the leading biocatalysts with proven potential for contributing to the multibillion worldwide enzyme market. On the other side, taking in advance the fact that Brazil generates, annually, thousands of tons of agricultural and agro industrial residues, the bioconversion of these residues for lipase production, as well as other value added products, would point out Brazil a prominent position in the future biotechnology developments. Oil cakes of various residues, obtained from extraction of oils, have been used as support and substrate for fermentative production of lipases, mainly in solid-state fermentation (SSF) technique. This is because their residual oil content serving as inducer for lipase production. Several agricultural residues have been reported to be effective for lipase production and these include brans, oil cakes, bagasse and soybean sludge (to be used as a supplement in SSF). The cottonseed and soybean cakes have attracted increasing attention as abundant and cheap renewable feedstocks and, additionally, it could reduce the human impact on the environment. Thus, the use of cottonseed and soybean cakes as substrates to produce microbial lipase, beyond being a cost-effective process, seems to be technically promising, once these residues have essential nutrient composition for microorganism growth. Regarding microbial lipase production, Yarrowia lipolytica is well-known producer of a large variety of bioproducts, but lipase is the most relevant biomolecule produced by this yeast. In this way, the soybean cake and its sludge were used in synergy for lipase production by Y. lipolytica in SSF and presented promising results like139±3 U/g in 14h of fermentation, reaching 9.9 U/g*h of productivity. The cottonseed cake was also used as substrate in SSF and reached a very good level of enzyme activity, 102 ± 6 U/g in 28h of fermentation, without use of any supplement.
