@article{mbs:/content/journal/ijsem/10.1099/ijs.0.023887-0, author = "Gridneva, Elena and Chernousova, Elena and Dubinina, Galina and Akimov, Vladimir and Kuever, Jan and Detkova, Ekaterina and Grabovich, Margarita", 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", journal= "International Journal of Systematic and Evolutionary Microbiology", year = "2011", volume = "61", number = "4", pages = "916-925", doi = "https://doi.org/10.1099/ijs.0.023887-0", url = "https://www.microbiologyresearch.org/content/journal/ijsem/10.1099/ijs.0.023887-0", publisher = "Microbiology Society", issn = "1466-5034", type = "Journal Article", abstract = "Seven strains of the genus Sphaerotilus were obtained from natural thermal sulfide (strains D-501T, D-502, D-504, D-505 and D-507) and low-temperature ferrous (strain HST) springs and from an activated sludge system (strain D-380). These Sphaerotilus isolates and strainsof Sphaerotilus natans obtained from the DSMZ (S. natans DSM 6575T, DSM 565 and DSM 566) were studied using a polyphasic taxonomic approach. All strains had Q-8 as the major quinone and C16 : 1ω7, C16 : 0 and C18 : 1ω7 as the major fatty acids. The DNA–DNA hybridization results and 16S rRNA, hsp60 and gyrB gene sequencing experiments showed that isolates D-501T, D-502, D-504, D-505, D-507 and D-380 were closely related to the type strain of S. natans DSM 6575T. However, strains D-501T, D-502, D-504, D-505 and D-507 significantly differed from the heterotrophic strain S. natans DSM 6575T 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-501T, 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-501T = DSM 22545T = VKM B-2573T) 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 6575T. Strains D-380 and S. natans DSM 6575T were assigned to the subspecies Sphaerotilus natans subsp. natans subsp. nov. (type strain DSM 6575T = ATCC 13338T). The 16S rRNA, hsp60 and gyrB gene sequences obtained for strains HST and DSM 565 showed very low sequence similarity values of 97.3 %, 89.7 % and 88.4 %, respectively, with S. natans DSM 6575T. Strain HST shared 99 % DNA–DNA relatedness with strain DSM 565 and 48 % with S. natans DSM 6575T. The 16S rRNA, hsp60 and gyrB gene sequence similarities between strain DSM 566T and S. natans DSM 6575T were 97.5 %, 91.5 % and 87.0 %, respectively. Strain DSM 566T had 52 % DNA–DNA relatedness to S. natans DSM 6575T and shared 44 % DNA–DNA similarity with strain HST. The creation of two novel species is proposed, Sphaerotilus montanus sp. nov. for strains HST and DSM 565 (type strain HST = DSM 21226T = VKM B-2519T) and Sphaerotilus hippei sp. nov. for strain DSM 566T (type strain DSM 566T = ATCC 29330T). Emended descriptions of the genus Sphaerotilus and of Sphaerotilus natans are presented. ", }