Diversity of l -Methionine Catabolism Pathways in Cheese-Ripening Bacteria

Enzymatic activities that could be involved in methanethiol generation in five cheese-ripening bacteria were assayed, and the major sulfur compounds produced were identified. l -Methionine and α-keto-γ-methyl-thio-butyric acid demethiolating activities were detected in whole cells and cell extracts (CFEs) of all the bacteria tested. No l -methionine deaminase activity could be detected in any of the ripening bacteria and l -methionine aminotransferase was detected in CFEs of Brevibacterium linens , Micrococcus luteus , and Corynebacterium glutamicum . The results suggest that several pathways for l -methionine catabolism probably coexist in these ripening bacteria.