Optimization of Lipase Production from Egyptian Aspergillus niger Isolates

Microbial lipase plays a crucial role in industrial biotechnology by contributing to a wide range of industrial products worldwide. Seeking potential lipase producers and enhancing their productivity represent a current urge. This study focuses on optimizing the culture conditions required for the extracellular production of lipase by Aspergillus niger isolates through submerged fermentation. Aspergillus niger was isolated from different herbal seeds and oily sources. Seven fungal isolates could be morphologically identified by the Assiut University Mycological Center (AUMC) and were cultivated on Czapek's Dox Medium. Various pH values, temperatures, oil concentrations, and metal ion (Mn2+, Zn2+, Cu2+ and Mg2+) concentrations were investigated to assess their impact on isolates growth, total extracellular protein concentration, and lipase activity. For the isolate AUMC 16212, optimum lipase production was reached at (pH 5 / 37°C / 3% corn oil / 10 mM Mn2+ / 10 mM Cu2+ / 2 mM Zn2+ / 22 mM Mg2+). While that from AUMC 16213 isolate was (pH 5 / 37°C / 3% corn oil / 8 mM Mn2+ / 10 mM Cu2+ / 2 mM Zn2+ / 22 mM Mg2+). The culture conditions of two isolates of Aspergillus niger (AUMC 16212 and 16213) could be optimized for potential lipase production which is of ascending industrial and economical value.