Lipase production from Rhizopus arrhizus with solid state fermentation

Ill SUMMARY Master Thesis LIPASE PRODUCTION FROM RHIZOPUS ARKHIZUS WITH SOLED STATE FERMENTATION Aysun ORHAN University of Fırat Graduate School of Natural and Applied Science Department of Chemical Engineering 2002, Page 87 In this study, some process conditions for lipase production by Rhizopus arrhizus were investigated using solid-state fermentation technique. In the first part of the study, wheat bran which is nutritionally rich but is not important commercially was used as a carbon source. The highest lipolytic activity reached was 752 umole/L.min. which was obtained in the presence of 5 % (w/v) wheat bran, with a particle size of 0.3 mm and at pH: 6.67. The effects of initial spore concentration and agitation rate on lipase production were also studied. Having found the optimum process conditions, fermentation medium was supplemented with some chemicals such as corn oil, glucose, yeast extract, MgS04.7H20, K2HPO4 and KH2PO4 in order to improve lipase production. In the second part of the work, sun flower waste was used as a solid substrate. The maximum enzyme activity (625.175 jimole/L.min.) was obtained at 5 % (w/v) waste concentration using 0.15 mm particle size. In order to get comparable results, similar parameters were investigated in the precense of sun flower oil waste....,; \,, "-^ '* ÂIV In order to measure the activity of lipase produced, a 30 ml working capacity reactor with pH, temparature and agitation control was used throughout the experiments. The activity of lipase was determined by titrimetric method in which a certain amount of NaOH was used to neutralise the fatty acids released during the hydrolysis. Key words: Rhizopus arrhizus, Lipase Enzyme, Solid State Fermentation, Wheat Bran, Sun Flower Pulp.