Diversity of L-methionine catabolism pathways in cheese-ripening bacteria

Enzymatic activities that could be involved in methanethiol generation in f ive cheese-ripening bacteria were assayed, and the major sulfur compounds p roduced were identified. L-Methionine and alpha -keto-gamma -methyl-thiobut yric acid demethiolating activities were detected in whole cells and cell e xtracts (CFEs) of all the bacteria tested. No L-methionine deaminase activi ty could be detected in any of the ripening bacteria and L-methionine amino transferase was detected in CFEs of Brevibacterium linens, Micrococcus lute us, and Corynebacterium glutamicum, The results suggest that several pathwa ys for L-methionine catabolism probably coexist in these ripening bacteria.