The influence of plant oil on the production of lipases enzyme from Staphylococcus aureus isolated from imported cheeses

Abstract

Milk and dairy products are very important as food sources. However, they are usually contaminated with members of the genus Staphyloccocus especially that liberate lipolytic enzymes. Thus the goals of this research were the, production of lipolytic enzymes at 37^₀C and 20^₀C by Staphyloccocus aureus that isolated from imported cooked cheese, lipases enzymes activity screened at different plant oils, activation or inhibition of lipase production using different plant oils. Rhodamine B agar, tween 80 agar and Baird- Packer containing sodium tolerite agar were used for the detection of lipase, esterase and lecithinase enzyme respectively. Lipase enzyme was estimated by titration method using olive oil as a substrate. The results showed that fourteen isolates representing to 70% were lipase and lecithinase producer they gave orange florescence color on the top of rhodamine B plate and turbid zone on bed parker telurite agar respectively, while esterase enzyme could detected from only two isolates that represented to 10 %. The production of lipase and esterase was depended on time and temperature, both enzymes secreted after 18 h incubated at 37^₀C and 72h at 20^₀C; their activity were increased with time to reach the maximum activity after 72h at 37^₀C and 96h at 20^₀C. The best lipase producing isolate was S. aureus KK1; its lipase was more active in hydrolyzing garlic oil followed by fingureek and castor oils at both 37^₀C and 20^₀C. The results cleared that castor oil, tween 80 and seasam were supported maximum lipase production which reached to 23.3, 20 and 13.2 U ml^-1 respectively after 48 hr in compares with 6 U/ml produced at nutrient broth. Otherwise inhibition of lipase production recognized among other plant oils, from wheat germ 3.5 to mint 0.33U ml^-1.