Dissimilation of Aromatic Compounds by Rhodotorula Graminis
The yeast Rhodotorula graminis utilizes benzoate, D,L-mandelate, phenylalanine, and salicylate as sole sources of carbon and energy. Pathways for phenylalanine and mandelate catabolism converge at benzoate; growth of R. graminis on phenylalanine, man-delate, and benzoate elicits the synthesis of benzoate-4-hydroxy-lase, £-hydroxybenzoate-3-hydroxylase, and protocatechuate-3,4-dioxygenase; these enzymes were not detected in crude extracts prepared from salicylate-grown cells. Mutants deficient in either £-hydroxybenzoate-3-hydroxylase or protocatechuate-3,4-dioxygenase were unable to utilize benzoate, phenylalanine, or mandelate; salicylate, however, did support growth. Revertants obtained from either class of mutants resulted in wild-type growth on benzoate, phenylalanine, and mandelate.