title: Adding value to the oil cake as a waste from oil processing industry: production of lipase and protease by Candida utilis in solid state fermentation.
abstract: Olive oil cake is a by-product from the olive oil processing industry and can be used for the lipase and protease production by Candida utilis in solid state fermentation. Different carbon and nitrogen sources were evaluated, and the results showed that the supplementation of the substrate with maltose and starch as carbon sources and yeast extract as a nitrogen source significantly increased the lipase production. The best results were obtained with maltose, whereas rather low lipase and protease activities were found with glucose and oleic acid. Response surface methodology and a five-level-three-factor central composite rotatable design were used to evaluate the effects of the initial moisture content, inoculum size and fermentation time on both lipase and protease activity levels. A lipase activity value of ≈25 U g(-1) and a protease activity value of 110 U g(-1) were obtained under the optimized fermentation conditions. An alkaline treatment of the substrate appeared to be efficient, leading to increases of 39% and 133% in the lipase and protease production, respectively. The results showed that the olive cake could be a good source for enzyme production by solid state fermentation.
authors.affiliation: Department of Biochemical Engineering and Biotechnology, Faculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, 11000 Belgrade, Serbia.
authors.forename: Omar Ali Saied
authors.initials: OA
authors.lastname: Moftah
authors.forename: Sanja
authors.initials: S
authors.lastname: Grbavčić
authors.forename: Milena
authors.initials: M
authors.lastname: Zuža
authors.forename: Nevena
authors.initials: N
authors.lastname: Luković
authors.forename: Dejan
authors.initials: D
authors.lastname: Bezbradica
authors.forename: Zorica
authors.initials: Z
authors.lastname: Knežević-Jugović
mesh_terms: D002175:Candida / Q000166:cytology / Q000378:metabolism*; D002244:Carbon / Q000378:metabolism; D049109:Cell Proliferation; D005285:Fermentation; D019649:Food Industry; D007101:Immersion; D007220:Industrial Waste; D007700:Kinetics; D008049:Lipase / Q000096:biosynthesis*; D009584:Nitrogen / Q000378:metabolism; D000069463:Olive Oil; D010316:Particle Size; D010447:Peptide Hydrolases / Q000096:biosynthesis*; D010938:Plant Oils / Q000737:chemistry / Q000378:metabolism*
chemical_list: D007220:Industrial Waste; D000069463:Olive Oil; D010938:Plant Oils; D002244:Carbon; D008049:Lipase; D010447:Peptide Hydrolases; D009584:Nitrogen