Some Characteristics of Continuous Glycerolysis of Fat by Lipase with Microporous Membrane Bioreactor

Various characteristics of the continuous glycerolysis of corn oil by pure Pseudomonas fluorescens lipase in a microporous hydrophobic flat membrane bioreactor were studied. By on-line continuous measurement of electric conductivity with a flow cell type electrode, the moisture content of the microaqueous glycerol containing the enzyme was monitored. The effect of moisturec ontent in the microaqueous glycerol on the glycerolysis reactions with the pure enzyme differed slightly from that with a crude enzyme as reported previously. The critical moisture content above which free fatty acids were formed was 3%, this being 1% less than that for the crude enzyme. The microporous hydrophobic flat membrane made of poly (tetrafluoroethylene) (PTFE) gave somewhat better conversions of the outlet product than did the polypropylene membrane at the same flow rates of the oil. Calcium chloride dissolved in the glycerol-water-lipase solution stabilized significantly the enzyme under non-reactive conditions without oil phase but destabilized it slightly during continuous reactions with oil.