Optimization of the fermentation conditions and substrate specifity of mycelium-bound ester hydrolases of Aspergillus oryzae Cs007

Abstract

In order to improve the activities of mycelium-bound ester hydrolases of Aspergillus oryzae Cs007, the main production conditions were investigated. The activities of the ester hydrolases were simultaneously determined by titration assay and spectrophotometric assay methods, using olive oil and p-nitrophenyl esters as substrates, respectively. The optimum carbon source and nitrogen source were olive oil and peptone, at concentrations of 1 and 2.2 %, respectively. The effects of the carbon source, the nitrogen source and their concentrations on the production of the enzymes were identical when the enzymes activities were assayed by the two methods. The mycelium-bound enzymes showed hydrolytic activity toward all the tested p-nitrophenyl esters, triglycerides and fatty acid ethyl esters, but it showed greater preference for long-chain triglycerides and short-chain p-nitrophenyl esters.