ENHANCED EXCRETION OF INTERMEDIATES OF AROMATIC AMINO-ACID CATABOLISMDURING CHLOROPHENOL DEGRADATION DUE TO NUTRIENT LIMITATION IN THE YEAST CANDIDA-MALTOSA

Incubation of phenol-induced cells of the yeast Candida maltosa SBUG 7 00 with mono- and dichlorophenols resulted in the formation of metabol ites of the substrates and of further metabolites not related to the d egradation pathway of the substrates. These additional compounds, iden tified as 4-hydroxyphenylacetic acid (4-HPA), phenylacetic acid (PA), indolylacetic acid (IA) and indolylethanol (IE) by means of HPLC and G C/MS, were not excreted in incubation experiments with glucose. The ex cretion of these metabolites of aromatic amino acid metabolism is not caused by toxic effects of the phenol derivatives, but seems to be a r esult of carbon and nitrogen starvation of yeast cells.