Isolation of methyl mercaptan-producing bacteria from porcine small intestine under storage

Methyl mercaptan (MM)-producing anaerobes in porcine small intestine (PSI) during storage were isolated and identified by enriched culture using methionine. Some facultative anaerobes were found to produce MM, among which Proteus mirabilis predominated both in the number isolated and the amount of +MM produced. Sulfur-containing amino acids, such as methionine and cystine, enhanced the production of MM by the bacterium both in situ and in vitro. These results indicate that the evolution of MM during storage of PSI is due mainly to Proteus mirabilis