Optimization of Lipase Production by a Newly Isolate of Lactobacillus Fermentum

There have been few findings on lipase synthesis from lactic acid bacteria (LAB) as compared to other categories of microorganisms. In this study, screening of lipase-producing lactobacilli from native dairy products was performed. Qualitative evaluation of lipolytic activity of lipase-producing lactobacilli was performed in different media. A clear zone observation around the colonies indicated the lipolytic activity. Among screened lipolytic bacterial strains, one sample (5c isolate) which showed the highest enzymatic activity was identified and confirmed by 16S rRNA gene sequence method with 98% identity to Lactobacillus fermentum ( L. fermentum ) under accession number of MH333208. Statistical experimental design including one-factor-at-a-time (OFAT) method was used to enhance the production of lipase by newly isolate of L. fermentum . NH 4 Cl and temperature were the most influential parameters on lipase production and exhibited a positive influence among the twelve independent variables investigated in the Plackett–Burman (PB) design. The optimum values of three significant components influencing lipase production were determined by response surface methodology (RSM). The validity of the model developed was verified, and the optimum medium containing 4.23 g/l NH4Cl, temperature of 37.7 °C and 2% (v/v) inoculum size led to a maximum lipase production 1842.8 U/ml of culture medium which was 1.15 times above the unoptimized medium. These findings could be used for the future upscale lipase production using L. fermentum ’s native isolate. Also, this work demonstrated the feasibility of statistical methodology to develop optimum medium composition for efficient lipase production using LAB isolates.