title: Influence of Oxygen and pH on Methanethiol Production from l-Methionine by Brevibacterium linens CNRZ 918.
abstract: The effects of dissolved oxygen concentration and pH on the growth of Brevibacterium linens CNRZ 918 and its production of methanethiol from l-methionine were investigated. Optimal specific methanethiol production was obtained at 25% saturation of dissolved oxygen and at a pH between 8 and 9, whereas optimal cell growth occurred at 50% oxygen saturation and when the pH was maintained constantly at 7. Methanethiol production by nonproliferating bacteria required the presence of l-methionine (7 mM) in the culture medium. This was probably due to the induction of enzyme systems involved in the process. The intracellular concentration of l-methionine seemed to play a key role in this process. B. linens CNRZ 918 tolerated alkaline pHs with a maximal growth pH of approximately 9. Its orange pigmentation seemed to depend on the presence of l-methionine in the culture medium and on the concentration of dissolved oxygen.
authors.affiliation: Laboratoire de Microbiologie Laitière, Institut National de la Recherche Agronomique, Centre National de Recherches Zootechniques, 78350 Jouy-en-Josas, France.
authors.forename: M
authors.initials: M
authors.lastname: Ferchichi
authors.forename: D
authors.initials: D
authors.lastname: Hemme
authors.forename: C
authors.initials: C
authors.lastname: Bouillanne