Vol. 9, Special Issue 1, Part B (2025)

Lipases are hydrolases (EC 3.1.1.3), belonging to serine hydrolases catalysing the hydrolysis of triacylglycerol into diacylglycerol and fatty acids. Lipases are important enzymes for various industries like Detergent, Organic chemistry, Food, Leather, Textiles, Pharmaceuticals, etc. There is always need of enzyme with easy availability, high productivity, low processivity and high activity.

Using tributyrin agar and oil agar plate lipase producing bacteria were isolated from different soil samples based on zone of clearance. Growth and lipase production conditions were standadised for best isolate. Further lipases were partially purified using Ammonium sulphate precipitation followed by dialysis. Partially purified enzyme was further characterised for optimum ezymatic conditions and applicability.

Screening of 3 different oil contaminated soil samples led to isolation 12 different lipolytic bacteria. Out of 12 isolates, isolate-7 producing highest zone of clearance was selected. Microscopic and biochemical examination revealed it to be Bacillus sp. Selected isolate Bacillus sp. (Isolate 7) showed optimum growth and lipase production after 48 h of growth and at temperature 37 °C and pH 8. Medium optimization showed that supplementation of sucrose, ammonium nitrate and sesame oil many folds enhance the enzyme production. Partially purified lipase enzyme of Bacillus sp. (Isolate 7) showed optimum activity after 20 min of incubation with substate at 55 °C temperature and pH 7. Enzyme is thermostable and have applicability for industrial and domestic applications. Further optimisation is needed for efficient application of it in detergent industries.