Production of lipase enzyme from thermotolerant Bacillus coagulans by solid-state fermentation technique

vıı SUMMARY Use of enzymes has been attracted considerable interested in biotechnological areas. One of these group of enzymes is lipases. These type of enzymes are widely used in fat modifications, drug industry (digest enzymes), clinical areas (hydrolyzing the glycerides) and as cleaner (detergent additives). Lipase production with SSF technique is the subject of recent extensive investigation since this technique is become a commercially important process. For this reason, our project aims to produce lipase with SSF technique by using Bacillus coagulans as a biological material. Melon, water melon and banane waste, rice and lentil husk and wheat bran were used as substrate to determine the best substrate. Melon waste was found to be the best substrate for the production of enzyme (78.100 Ug"1) and therefore, used as a substrate for further studies. Appropriate incubation time, optimum temperature and optimum pH were found 24 h, 37 °C and pH: 7.0 respectively, for the enzyme. To investigate the effect of various oils on lipase production, bacteria was produced in growth medium which obtained from olive oil, sunflower oil, corn oil, soya oil and tributyrin. Olive oil (1 %) gave the best result. Bacteria was produced in growth medium which containing different olive oil concentrations (1; 2; 3; 4; 5; 6; 7 %) for the effect of olive oil concetration on enzyme activity. Appropriate olive oil concentration was found to be 2 %. The effect of different surfactants such as sodium dodecyl sulphate, Triton X-100, gum arabic and polyethylene glycol (PEG) and different carbon, nitrogen and carbon-nitrogen containing compounds were examined by using above concentration of olive oil. Obtained results indicated that maximum activity was observed in the following order; SDS, starch, maltose and NH4NO3. Finally, the effect of metal ions on enzyme production was tested and it was found that enzyme was activated 105 % by Ca2+ ion but inhibited 32 % and 26 % by Mn2+ and Ni2+, respectively. Keywords: Bacillus coagulans, SSF, lipase production