SUBSTRATE PREFERENCE OF MYCELIUM-BOUND LIPASE FROM A STRAIN OF ASPERGILLUS-FLAVUS LINK

Aspergillus flavus mycelium-bound lipase demonstrates high perference towards short chain triacylglycerols and discriminates against triunsa turated tricylglycerols e.g. triolein. The great discriminating power of its lipase against triolein was shown in comparison with its abilit y to catalyse the hydrolysis of shorter chain tricylglycerols e.g. tri caprin and less was shown when hydrolysing tripalmitin. A similar phen omenen was noted when the mycelium-bound lipase was used to catalyse t he reaction of coconut oil with palmitic acid or oleic acid in n-hexan e. The relative percentages of octanoic acid and decanoic acid of coco nut oil remaining after 20 h reaction were much less than those of the medium, long and unsaturated chain fatty acids suggesting that short chain fatty acids are preferred. The lipase hydrolyses coconut oil fas ter than palm olein followed by corn oil, rapeseed oil, soy bean oil a nd cottonseed oil. This indicates that A. flavus lipase has preference for oils containing saturated fatty acids rather than unsaturated fat ty acids.