EFFECTS OF STIRRING AND AERATION RATES ON LIPASE PRODUCTION AND GROWTH OF R. DELEMAR IN THE MEDIA CONTAINING GLUCOSE OR MOLASSES SUCROSE AND PFC

Abstract

Lipases (triacylglycerol hydrolases) are hydrolytic enzymes that can catalyze the hydrolysis of the ester bond of long-chain acylglycerols at the oil-water interface. The effects of stirring rate, aeration rate, and the amount of perfluorocarbon (PFC), as an oxygen carrier, in the nutrient media containing glucose or molasses sucrose as main carbon sources were investigated in a batch bioreactor. The maximum lipase activities in the media containing glucose or molasses sucrose as main C source were found to be 43.0 U/L and 102.83 U/L, respectively, at the stationary phase of growth (120th hour of fermentation), at 150 and 200 revolution per minute stirring rates, respectively. The effect of aeration rate on lipase activity was investigated in range of 1-4 vvm. The maximum lipase activities in the media containing glucose or molasses sucrose and 10% PFC were determined as 102.67 U/L, 171.20 U/L, respectively, at 2 vvm aeration rate.