title: Geobacillus jurassicus sp. nov., a new thermophilic bacterium isolated from a high-temperature petroleum reservoir, and the validation of the Geobacillus species.
abstract: Four thermophilic, spore-forming bacterial strains, DS1(T), DS2, 46 and 49, were isolated from the high-temperature Dagang oilfield, located in China. The strains were identified by using the polyphasic taxonomy approach. These were aerobic, gram-positive, rod-shaped, moderately thermophilic (with an optimum growth temperature of 60-65 degrees C), chemoorganotrophic bacteria capable of growing on various sugars, carboxylic acids and crude oil. Two strains, DS1(T) and DS2, were capable of growing on individual saturated hydrocarbons. The G + C content of the DNA of strains DS1(T) and DS2 was 54.5 and 53.8 mol%, respectively. The phylogenetic analysis of the 16S rDNA of strains DS1(T) and DS2 showed that they form a separate cluster within the genus Geobacillus. The cellular fatty acids of the isolates were dominated by iso-15:0, iso-16:0 and iso-17:0 acids, which are the typical fatty acids of bacteria from the genus Geobacillus. The DNA-DNA hybridization study and the comparative analysis of the morphological and chemotaxonomic characteristics of strains DS1(T) and DS2 showed that they differ from the previously described Geobacillus species and belong to a new species, which was called Geobacillus jurassicus. DS1(T) (=VKM B2301(T), = DSM 15726(T)) is the type strain of this species. According to both DNA-DNA reassociation studies and 16S rDNA sequence analysis, two other strains, 46 and 49, were assigned to the species G. stearothermophilus. In this paper, we provide evidence that the new combinations G. stearothermophilus, G. thermoleovorans, G. kaustophilus, G. thermoglucosidasius and G. thermodenitrificans may be considered to be valid.
authors.affiliation: Winogradsky Institute of Microbiology, Russian Academy of Sciences, pr. 60-letiya Oktyabrya 7/2, Moscow 117312, Russian Federation. nazina@inmi.host.ru
authors.forename: Tamara N
authors.initials: TN
authors.lastname: Nazina
authors.forename: Diana Sh
authors.initials: DSh
authors.lastname: Sokolova
authors.forename: Alexander A
authors.initials: AA
authors.lastname: Grigoryan
authors.forename: Nataliya M
authors.initials: NM
authors.lastname: Shestakova
authors.forename: Ekaterina M
authors.initials: EM
authors.lastname: Mikhailova
authors.forename: Andrei B
authors.initials: AB
authors.lastname: Poltaraus
authors.forename: Tatiyana P
authors.initials: TP
authors.lastname: Tourova
authors.forename: Anatolii M
authors.initials: AM
authors.lastname: Lysenko
authors.forename: George A
authors.initials: GA
authors.lastname: Osipov
authors.forename: Sergey S
authors.initials: SS
authors.lastname: Belyaev
mesh_terms: D000332:Aerobiosis; D001406:Bacillaceae / Q000145:classification* / Q000166:cytology / Q000302:isolation & purification* / Q000502:physiology; D015373:Bacterial Typing Techniques; D001482:Base Composition; D050260:Carbohydrate Metabolism; D002264:Carboxylic Acids / Q000378:metabolism; D002681:China; D004269:DNA, Bacterial / Q000737:chemistry / Q000302:isolation & purification; D004275:DNA, Ribosomal / Q000737:chemistry / Q000302:isolation & purification; D004783:Environmental Microbiology; D005227:Fatty Acids / Q000032:analysis / Q000302:isolation & purification; D020459:Genes, rRNA; D005840:Gentian Violet; D006838:Hydrocarbons / Q000378:metabolism; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D010578:Petroleum / Q000378:metabolism / Q000382:microbiology*; D010619:Phenazines; D010802:Phylogeny; D012329:RNA, Bacterial / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D013171:Spores, Bacterial / Q000166:cytology; D013696:Temperature
chemical_list: D002264:Carboxylic Acids; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D005227:Fatty Acids; C035863:Gram's stain; D006838:Hydrocarbons; D010578:Petroleum; D010619:Phenazines; D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S; D005840:Gentian Violet