Screening and optimization of submerged fermentation of lipolytic Aspergillus oryzae

Abstract

Lipases are enzymes commonly used in industry. This study describes the production of lipolytic enzyme via a newly isolated strain of Aspergillus oryzae under a submerged fermentation process. Five strains of A. oryzae were isolated from oil-contaminated soil and water as well as dead decaying organic matter. Qualitative screening revealed that A. oryzae RBM4 strain was a lipase producer, and the process was optimized for enhanced production. Incubation time, incubation temperature, initial pH, use of agricultural by-products, nitrogen sources, and substrates were tested. The results revealed that initial pH 5.5(12.7 U/mL/min) in 72 h (19.39 U/mL/min) at 30 °C (27.40 U/mL/min) sorghum (35.66 U/mL/min), NaNO3 (17% more than blank), yeast extract (47.95 U/mL/min), and Shan ghee (58.12 U/mL/min) were the best conditions. Extracellular lipase production was increased up to 78% by applying all the above conditions.