FATTY-ACID SELECTIVITY - THE SELECTIVITY OF LIPASES OF GEOTRICHUM-CANDIDUM

The relative reactivities of several long chain fatty acids in esterifications with 1-butanol catalyzed by lipases of Geotrichum candidum were evaluated. As has been noted previously, these lipases are not uniformly highly selective for cis-9 unsaturated fatty acids. However, the lipase preparations examined do uniformly discriminate against fatty acids having a chainlength greater than C-18 such as erucic acid. The reactivities of gamma-linolenic and ricinoleic acid were also low compared to that of oleic. An examination of the effect of the alcohol upon the relative reactivities of acids showed that one could enhance fatty acid selectivity by proper choices of alcohol. For example, oleic acid esterifies 2.5 times faster than palmitic acid with 1-butanol catalyzed by Amano GC-4 lipase, but esterifies over 50 times faster with 2-methyl-1-propanol or cyclopentanol.