title: Taxonomic investigation of representatives of the genus Sphaerotilus: descriptions of Sphaerotilus montanus sp. nov., Sphaerotilus hippei sp. nov., Sphaerotilus natans subsp. natans subsp. nov. and Sphaerotilus natans subsp. sulfidivorans subsp. nov., and an emended description of the genus Sphaerotilus.
abstract: Seven strains of the genus Sphaerotilus were obtained from natural thermal sulfide (strains D-501(T), D-502, D-504, D-505 and D-507) and low-temperature ferrous (strain HS(T)) springs and from an activated sludge system (strain D-380). These Sphaerotilus isolates and strains of Sphaerotilus natans obtained from the DSMZ (S. natans DSM 6575(T), DSM 565 and DSM 566) were studied using a polyphasic taxonomic approach. All strains had Q-8 as the major quinone and C(16 : 1)ω7, C(16 : 0) and C(18 : 1)ω7 as the major fatty acids. The DNA-DNA hybridization results and 16S rRNA, hsp60 and gyrB gene sequencing experiments showed that isolates D-501(T), D-502, D-504, D-505, D-507 and D-380 were closely related to the type strain of S. natans DSM 6575(T). However, strains D-501(T), D-502, D-504, D-505 and D-507 significantly differed from the heterotrophic strain S. natans DSM 6575(T) by their capability for lithotrophic growth with reduced sulfur compounds as an electron donor for energy conservation and some other phenotypic features. For this reason, strains D-501(T), D-502, D-504, D-505 and D-507 merit a separate taxonomic classification at the subspecies level. The name Sphaerotilus natans subsp. sulfidivorans subsp. nov. (type strain D-501(T) = DSM 22545(T) = VKM B-2573(T)) is proposed. The subspecies Sphaerotilus natans subsp. natans subsp. nov. is automatically created as a result of this proposal. Strain D-380 was phenotypically closely related to S. natans DSM 6575(T). Strains D-380 and S. natans DSM 6575(T) were assigned to the subspecies Sphaerotilus natans subsp. natans subsp. nov. (type strain DSM 6575(T) = ATCC 13338(T)). The 16S rRNA, hsp60 and gyrB gene sequences obtained for strains HS(T) and DSM 565 showed very low sequence similarity values of 97.3 %, 89.7 % and 88.4 %, respectively, with S. natans DSM 6575(T). Strain HS(T) shared 99 % DNA-DNA relatedness with strain.
authors.affiliation: Department of Biology, University of Voronezh, Universitetskaya pl. 1, 394006 Voronezh, Russia.
authors.forename: Elena
authors.initials: E
authors.lastname: Gridneva
authors.affiliation: G. K. Skryabin Institute of Biochemistry and Physiology of Microorganisms, Russian Academy of Sciences, Prospect Nauki 5, 142290 Pushchino, Russia.|Department of Biology, University of Voronezh, Universitetskaya pl. 1, 394006 Voronezh, Russia.
authors.forename: Elena
authors.initials: E
authors.lastname: Chernousova
authors.affiliation: S. N. Winogradsky Institute of Microbiology, Russian Academy of Sciences, Prospect 60-letiya Oktyabrya 7/2, 117312 Moscow, Russia.
authors.forename: Galina
authors.initials: G
authors.lastname: Dubinina
authors.affiliation: G. K. Skryabin Institute of Biochemistry and Physiology of Microorganisms, Russian Academy of Sciences, Prospect Nauki 5, 142290 Pushchino, Russia.
authors.forename: Vladimir
authors.initials: V
authors.lastname: Akimov
authors.affiliation: Department of Microbiology, Bremen Institute for Materials Testing, Paul-Feller Str. 1, D-28199 Bremen, Germany.
authors.forename: Jan
authors.initials: J
authors.lastname: Kuever
authors.affiliation: S. N. Winogradsky Institute of Microbiology, Russian Academy of Sciences, Prospect 60-letiya Oktyabrya 7/2, 117312 Moscow, Russia.
authors.forename: Ekaterina
authors.initials: E
authors.lastname: Detkova
authors.affiliation: Department of Biology, University of Voronezh, Universitetskaya pl. 1, 394006 Voronezh, Russia.
authors.forename: Margarita
authors.initials: M
authors.lastname: Grabovich
mesh_terms: D015373:Bacterial Typing Techniques; D018834:Chaperonin 60 / Q000235:genetics; D016000:Cluster Analysis; D027081:DNA Gyrase / Q000235:genetics; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D005227:Fatty Acids / Q000032:analysis; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D010802:Phylogeny; D011809:Quinones / Q000032:analysis; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D012722:Sewage / Q000382:microbiology*; D042744:Sphaerotilus / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D013457:Sulfur Compounds / Q000378:metabolism; D014871:Water Microbiology
chemical_list: D018834:Chaperonin 60; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D005227:Fatty Acids; D011809:Quinones; D012336:RNA, Ribosomal, 16S; D012722:Sewage; D013457:Sulfur Compounds; D027081:DNA Gyrase