Esterase and Lipase Activities of New Isolated Thermophilic Bacillus Strains HUTB 20 under Different Temperatures and in the Presence of various Carbon Sources

摘要

The activities of esterase and lipase by thermophilic Bacillus strain HUTB 20 were monitored during incubation at 53°C, 25“C and after 53“C to 25“C shift in growth temperature. Activities of both enzymes were increased after 27 hours growth but were undetectable or reduced from 0 hour up to 3 hours. The highest activities for both enzymes were at 53°C in the presence of olive oil. The highest enzymes activities obtained in sonicated cells followed by homogenized cells and then cell culture supernatant. At 25°C, esterase activity was higher than the activity of lipase in the presence of Tween 80 and Tween 20. However, lipase was in high activity than esterase in the presence of olive oil at 25°C. The activity of both enzymes was low after coldshock in the presence of various carbon sources. The increased activity of a cell associated esterase and extracellular lipolytic enzymes and production of an extracellular polysaccharide suggested that these enzymes are required for growth at low and high temperatures.