title: Growth requirements of hyperthermophilic sulfur-dependent heterotrophic archaea isolated from a shallow submarine geothermal system with reference to their essential amino acids.
abstract: Three hyperthermophilic sulfur-dependent heterotrophs were isolated from a shallow submarine hydrothermal system at an inlet of Kodakara-jima island, Kagoshima, Japan. The isolates grew at 60 to 97 degrees C, with the optimum temperatures at 85 to 90 degrees C. Sensitivity to rifampin and the existence of ether lipids indicated that the isolates are hyperthermophilic archaea. Partial sequencing of the genes coding for 16S rRNA showed that the three isolates are closely related to the genus Thermococcus. They grew on proteinaceous mixtures, such as yeast extract, Casamino Acids, and purified proteins (e.g., casein and gelatin), but not on carbohydrates or organic acids as sole carbon and energy sources. Nine amino acids were essential for growth of isolate KS-1 (Thr, Leu, Ile, Val, Met, Phe, His, Tyr, and Arg). Isolate KS-2 required Lys in addition to the nine amino acids, and KS-8 required Lys instead of Tyr. In comparative studies, it was shown that Thermococcus celer DSM 2476 required 10 amino acids (Thr, Leu, Ile, Val, Met, Phe, Tyr, Trp, Lys, and Arg) while Pyrococcus furiosus DSM 3638 required only Ile and Val. The hyperthermophilic fermentative eubacterium Thermotoga neapolitana DSM 4359 did not require any amino acids for growth.
authors.affiliation: Marine Biotechnology Institute, Shimizu Laboratories, Shizuoka, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Hoaki
authors.forename: M
authors.initials: M
authors.lastname: Nishijima
authors.forename: M
authors.initials: M
authors.lastname: Kato
authors.forename: K
authors.initials: K
authors.lastname: Adachi
authors.forename: S
authors.initials: S
authors.lastname: Mizobuchi
authors.forename: N
authors.initials: N
authors.lastname: Hanzawa
authors.forename: T
authors.initials: T
authors.lastname: Maruyama
mesh_terms: D000601:Amino Acids, Essential / Q000378:metabolism*; D000693:Anaerobiosis; D001105:Archaea / Q000235:genetics / Q000254:growth & development* / Q000502:physiology / Q000648:ultrastructure; D001482:Base Composition; D001483:Base Sequence; D003470:Culture Media; D004275:DNA, Ribosomal / Q000032:analysis; D006358:Hot Temperature; D008969:Molecular Sequence Data; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012623:Seawater; D017422:Sequence Analysis, DNA; D012988:Soil Microbiology
chemical_list: D000601:Amino Acids, Essential; D003470:Culture Media; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S