title: The effect of cysteine on production of volatile sulphur compounds by cheese-ripening bacteria.
abstract: The effect of cysteine on the ability of smear cheese-ripening bacteria (Brevibacterium linens and Arthrobacter spp) to produce volatile sulphur compounds (VSC) from methionine was studied. These bacteria were cultivated in a synthetic medium supplemented with various cysteine concentrations with or without methionine. Cultures with only cysteine showed slightly lower levels of VSC produced and an unpleasant odour like rotten eggs, resulting from hydrogen sulphide production. The levels and profiles of VSC produced with supplemented methionine-cysteine mixtures had strain-dependant behaviours. However, the highest levels of dimethyl disulfide, dimethyl trisulfide and dimethyl tetrasulfide were observed when increasing the cysteine concentration from 0.2 to 1.0 gl(-1) at the same methionine concentration (1.0 gl(-1)). In contrast, production levels of thioesters, especially S-methylthio acetate, were reduced by 50 and 80% under such conditions. An initial sensory approach showed that such an effect could have a strong impact on the global odour of ripened cheeses.
authors.affiliation: UMR 782, AgroParisTech, Laboratoire de Génie et Microbiologie des Procédés Alimentaires, Centre de Biotechnologies Agro-Industrielles, 78850 Thiverval Grignon, France.
authors.forename: M López
authors.initials: ML
authors.lastname: del Castillo-Lozano
authors.forename: S
authors.initials: S
authors.lastname: Mansour
authors.forename: R
authors.initials: R
authors.lastname: Tâche
authors.forename: P
authors.initials: P
authors.lastname: Bonnarme
authors.forename: S
authors.initials: S
authors.lastname: Landaud
mesh_terms: D001173:Arthrobacter / Q000378:metabolism*; D001951:Brevibacterium / Q000378:metabolism*; D002611:Cheese / Q000382:microbiology*; D015169:Colony Count, Microbial; D003545:Cysteine / Q000378:metabolism* / Q000494:pharmacology; D004220:Disulfides / Q000032:analysis / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D005516:Food Microbiology; D008715:Methionine / Q000378:metabolism*; D009812:Odorants / Q000032:analysis; D013440:Sulfides / Q000032:analysis / Q000378:metabolism; D013457:Sulfur Compounds / Q000032:analysis / Q000378:metabolism*; D014835:Volatilization
chemical_list: D004220:Disulfides; D013440:Sulfides; D013457:Sulfur Compounds; C054170:dimethyl trisulfide; C021181:dimethyl disulfide; D008715:Methionine; D003545:Cysteine