Screening, characterization, and optimization of lipase enzyme producing bacteria isolated from dairy effluents contaminated muddy soil

TLDR: In this paper, the authors identified the most potential lipase-producing bacterial strains from Aavin dairy industry effluent contaminated soil and optimized growth parameters such as pH, temperature, carbon and nitrogen sources, for lipase enzyme production from selected bacterial strains.

Abstract: Lipases, particularly microbial lipases, are important industrial biocatalysts. As a result, lipase enzyme screening, synthesis, and purification from microbial strains are constantly evolving to meet the needs of the pharmaceutical and food industries. Thus, the goal of this study was to identify the most potential lipase-producing bacterial strains from Aavin dairy industry effluent contaminated soil. Furthermore, growth parameters, such as pH, temperature, carbon and nitrogen sources, were optimized for lipase enzyme production from selected bacterial strains. According to the findings, 9 strains (V1–V9) of 15 bacterial isolates were found to be lipase producers. However, three strains (V1, V7, and V8) predominated and demonstrated significant lipase-producing activity. These V1, V7, and V8 bacterial strains were identified as Bacillus pumilus V1, Bacillus pumilus V7, and Bacillus subtilis V8 through 16S rRNA sequencing. About 16.6 to 27.8 µg mL−1 of lipase production was recorded under the optimal growth conditions: pH 8, temperature 37 °C, fructose and yeast extract as suitable carbon and nitrogen source. Among these 3 strains B. pumilus V1 showed excellent lipase productivity than others. The molecular weight of this lipase produced by bacteria was determined to be 35 kDa using sodium dodecyl sulphate–polyacrylamide gel electrophoresis (SDS-PAGE).