title: Separation of a phenol carboxylating organism from a two-member, strict anaerobic co-culture.
abstract: In a culture converting phenol to benzoic acid under anaerobic conditions and previously described as being constituted of only a Clostridium-like strain 6, another bacterium (strain 7) was observed. Each organism was enriched by centrifugation on a Percoll gradient. Strain 6 was purified by dilution and plating. Strain 7 did not grow on solid media, but a strain 7 culture, cleared of strain 6, was obtained by subculturing in the presence of ampicillin and by dilution. In fresh medium, phenol was transformed by the reconstituted co-culture but not by each strain alone. In a supernatant from a co-culture or from a strain 6 culture, strain 7 alone transformed phenol but not strain 6. Maintenance of an active strain 7 in fresh medium instead of co-culture supernatant became possible when phenol was replaced by 4-hydroxybenzoate (4-OHB), which is decarboxylated to phenol before being transformed to benzoate. Even with 4-OHB, the use of co-culture (or strain 6 culture) supernatant resulted in faster transformation activity and growth rate. A phylogenetic analysis placed strain 7 in a cluster of uncultivated or nonisolated bacteria (92-96% homology). Strain 7 is also related to Desulfotomaculum, Desulfitobacterium, Desulfosporosinus, Moorella, and Sporotomaculum genera (87-92% homology).
authors.affiliation: Institut national de la recherche scientifique (INRS), Institut Armand-Frappier, Microbiologie et biotechnologie, Université du Québec, Laval, Canada.
authors.forename: J
authors.initials: J
authors.lastname: Letowski
authors.forename: P
authors.initials: P
authors.lastname: Juteau
authors.forename: R
authors.initials: R
authors.lastname: Villemur
authors.forename: M F
authors.initials: MF
authors.lastname: Duckett
authors.forename: R
authors.initials: R
authors.lastname: Beaudet
authors.forename: F
authors.initials: F
authors.lastname: Lépine
authors.forename: J G
authors.initials: JG
authors.lastname: Bisaillon
mesh_terms: D001421:Bacteria, Anaerobic / Q000145:classification / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism*; D015373:Bacterial Typing Techniques; D001431:Bacteriological Techniques; D001673:Biodegradation, Environmental; D004275:DNA, Ribosomal / Q000235:genetics; D003653:Decarboxylation; D008969:Molecular Sequence Data; D010226:Parabens / Q000378:metabolism; D019800:Phenol / Q000378:metabolism*; D012150:Polymorphism, Restriction Fragment Length; D012336:RNA, Ribosomal, 16S / Q000235:genetics
chemical_list: D004275:DNA, Ribosomal; D010226:Parabens; D012336:RNA, Ribosomal, 16S; D019800:Phenol; C038193:4-hydroxybenzoic acid