ENHANCING BACILLUS LIPASE PRODUCTION: A COST-EFFECTIVE APPROACH UTILIZING AGRICULTURAL BY-PRODUCTS

Abstract

Microbial lipases have significant importance in many industries due to their multidimensional applications. Optimization of cultural conditions can play an important role in their productivity. The present research was based on the isolation of different lipolytic strains of Bacillus sp. from oil-contaminated soil, different food products and drainage water. A total of 15 strains were isolated, and 07 showed positive results in Tributyrin Clearing Zone assay. Among them, Bacillus sp. UOE-14 (isolated from oil contaminated soil) was quantitatively selected for further studies. Different parameters were studied for enhanced lipase production. Analysis of the data revealed that maximum enzyme activity was observed (27.9 U/mL/min) after 48 h incubation. Effect of pH, agricultural by-products and carbon sources were also studied, and results indicated that pH 8.5, wheat bran, and glucose were the most effective, yielding a 14% lipase increase. NaNO₃ as the inorganic nitrogen source was selected because it enhanced lipase production by up to 13% (56.5 U/mL/min). It was also observed that Shan ghee as substrate had great potential to enhance lipase activity (67.4 U/mL/min). The optimal temperature was 30°C for Bacillus sp. UOE-14 as at this temperature, lipase activity increased by 8.5% (73.7 U/mL/min). This investigation indicated that different parameters have significant influence on enzyme production and by applying these cultural conditions, lipase production was increased.