IndexAbstractIntroductionMaterials and methodsAbstractBacterial lipases are commercially more important mainly due to the ease of their cultivation and optimization to obtain higher yield. The isolation and selection of Bacillus subtilis stimulated the industrial demand for new sources of lipases with different catalytic characteristics. This study was designed to investigate the physicochemical parameters for optimized lipase production. Microbial lipases catalyze both the hydrolysis and synthesis of long-chain acylglycerols. They currently receive a lot of attention due to the rapid development of enzyme technology. Say no to plagiarism. Get a tailor-made essay on "Why Violent Video Games Shouldn't Be Banned"? Get an original essay The characterization of these enzymes is of fundamental importance to establish the process conditions for the subsequent application. To determine the optimal pH we used sodium citrate buffer at pH 3,3,6 and 5.6 and sodium phosphate buffer at pH 7.3 and 8. Changing pH also alters the shape of an enzyme. Different enzymes work better at different pH values. The enzyme can continue to bind to a substrate and continue its activity as a catalyst. If the pH is too high or too low it can change the shape of the enzyme. The most favorable pH value, i.e. the point at which the enzyme is most active, is known as the optimal pH. Extremely high or low pH values ​​generally result in a complete loss of activity for most enzymes. pH is also a factor in enzyme stability. As with the activity for each enzyme there is also a region of optimal pH stability. Keywords: lipase, enzymes, Bacillus subtilis, optimal, pH. Introduction Lipases (triacylglycerol acyl hydrolases, EC 3.1.1.3) are an important group of enzymes mainly due to the large number of industrial applications. From an industrial point of view, lipase enzymes are considered very important due to their greater large-scale production potential. Isolation of lipases using Bacillus subtills from different soil samples namely Ruchi Soya Oil Mill, Ghatabillod, Bajrang Soya Mill, Ghatabillod, Madhya Pradesh and Dairy Companies and characterization of bacteria was studied to determine the maximum producer of lipase by qualitative and quantitative means[1]. . Lipases are widely present in animals, plants and microorganisms, especially those originating from bacteria, they are more stable than others. Many microorganisms are known as good producers of extracellular lipases [2]. Studies on the production of extracellular lipases with Bacillus have shown variations between different strains [3]. Lipases are widely present in bacteria, yeasts and fungi [4]. Bacterial lipases are commercially more important mainly due to the ease of their cultivation and optimization for higher yield. Microbial lipases are in high demand due to their reaction specificity, stereospecificity and lower energy consumption compared to conventional methods[5]. Lipase with high enzymatic activity can replace the traditional catalyst in biodiesel processing as this enzyme replaces chemicals in a process that would otherwise require high energy consumption. [6]. Lipase applications are also influenced by temperature and pH stability. The enzyme is used as a catalyst for the production of various products used in the cosmetics industry [7], in the pulp and paper industry [8], in the synthesis of biodiesel [9], in leather degreasing and in the pharmaceutical [10]. They are also used in organic chemical processes, in the synthesis of biosurfactants,.