Phenylalanine and tyrosine catabolism in some cheese coryneform bacteria

23 cheese coryneform bacteria (14 orange, 3 white, and 6 yellow-pigmented) were examined for five enzymes of two branch-point steps in the catabolic pathways of l-phenylalanine and l-tyrosine. Orange cheese coryneforms (‘Brevibacterium linens’) catabolized th amino acids by transamination and the benzene ring was cleaved by 3, 4-dihydroxyphenylacetate-2, 3-dioxygenase. Both enzymes appear to be inducible. Yellow and white strains possessed non-inducible low activity of aminotransferase and lacked completely benzene ring cleavage enzymes.