Rhodotorula minuta, a basidiomycete fungus, prefers neutral pH for growth and its growth inhibition by food preservatives such as benzoic acid and cinnamic acid has not been reported. Cinnamic acid at 1 g l(-1) arrested the growth and decreased the respiration of Rhodotorula but did not kill the yeast. The inhibitory effect was stronger in a mutant strain, 5-286, deficient in the beta-ketoadipate pathway than in the wild, suggesting that beta-ketoadipate pathway functions to detoxify this acid by restoring the decreased respiration.