Phenylalanine ammonia lyase (PAL) enzyme activity of Rhodotorula glutinis has been demonstrated in four commonly used ionic liquids.

Enzyme activity of oligomeric PAL protein in the reaction mixture containing 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF₆]) is comparable to that obtained in aqueous buffer medium.

Various conditions were standardized for optimal PAL forward activity in the reaction mixture containing [BMIM][PF₆]; about 83% conversion of L-phenylalanine to trans-cinnamic acid was obtained.

PAL reverse activity in ionic liquids was shown for the first time; about 59% conversion of trans-cinnamic acid to L-phenylalanine was obtained in the reaction mixture containing [BMIM][PF₆].