title: Sulfur compound production by Geotrichum candidum from L-methionine: importance of the transamination step.
abstract: L-methionine degradation products and catabolic enzymatic activities involved in methanethiol generation were investigated in Geotrichum candidum GcG. L-methionine was easily degraded by G. candidum and the transamination product, 4-methylthio-2-oxobutyric acid (KMBA), was found to transiently accumulate. In parallel, considerable L-methionine aminotransferase activity was found in this microorganism. L-methionine and KMBA demethiolating activities were also detected. The degradation of KMBA corresponded to an overall increase in the production of volatile sulfur compounds. These results show that the transamination pathway is of major importance in the initial breakdown of L-methionine by this cheese-ripening microorganism.
authors.affiliation: Institut National de la Recherche Agronomique, Laboratoire de Génie et Microbiologie de Procédés Alimentaires, Thiverval-Grignon, France. bonnarme@grignon.inra.fr
authors.forename: P
authors.initials: P
authors.lastname: Bonnarme
authors.forename: K
authors.initials: K
authors.lastname: Arfi
authors.forename: C
authors.initials: C
authors.lastname: Dury
authors.forename: S
authors.initials: S
authors.lastname: Helinck
authors.forename: M
authors.initials: M
authors.lastname: Yvon
authors.forename: H E
authors.initials: HE
authors.lastname: Spinnler
mesh_terms: D002087:Butyrates / Q000378:metabolism; D002611:Cheese / Q000382:microbiology; D005516:Food Microbiology; D005848:Geotrichum / Q000378:metabolism*; D008715:Methionine / Q000378:metabolism*; D013438:Sulfhydryl Compounds; D013457:Sulfur Compounds / Q000378:metabolism*; D013997:Time Factors; D000637:Transaminases / Q000378:metabolism
chemical_list: D002087:Butyrates; D013438:Sulfhydryl Compounds; D013457:Sulfur Compounds; C045636:2-keto-4-mercaptobutyric acid; D008715:Methionine; D000637:Transaminases; C020656:glutamine-pyruvate aminotransferase