title: Alkalispirochaeta cellulosivorans gen. nov., sp. nov., a cellulose-hydrolysing, alkaliphilic, halotolerant bacterium isolated from the gut of a wood-eating cockroach (Cryptocercus punctulatus), and reclassification of four species of Spirochaeta as new combinations within Alkalispirochaeta gen. nov.
abstract: An obligately anaerobic spirochaete designated strain JC227T was isolated from the gut of a wood-eating cockroach, Cryptocercus punctulatus (Scudder), from the Rann of Kutch, Gujarat, India. Strain JC227T was Gram-stain-negative, mesophilic, halotolerant and alkaliphilic. Based on 16S rRNA gene sequence analysis, strain JC227T belongs to the genus Spirochaeta, with Spirochaeta sphaeroplastigenens JC133T (99.51%), S. odontotermitis JC202T (99.30%), S. alkalica Z-7491T (99.10%), S. americana (98.54%) and other members of the genus Spirochaeta (<92.7%) as its closest phylogenetic neighbours. However, DNA-DNA hybridization between strain JC227T and S. sphaeroplastigenens JC133T, S. odontotermitis JC202T, S. alkalica DSM 8900T and S. americana DSM 14872T was 62±2, 63, 58±2 and 48±4 %, respectively. Strain JC227T contained phosphatidylglycerol, diphosphatidylglycerol, an unidentified glycolipid and six unidentified lipids. Summed feature C18:1ω7c/C18:1ω6c was the predominant cellular fatty acid, with significant proportions of C16:0, C14:0, C12:0, C15:1ω6c, C16:1ω5c, C16:1ω6c/C16:1ω7c and C17:0 2-OH. The DNA G+C content of strain JC227T was 55.5 mol%. On the basis of physiological, biochemical, chemotaxonomic (including metabolomic) and genomic differences from previously described taxa, strain JC227T can be differentiated from members of the genus Spirochaeta and represents a novel species of a new genus, for which the name Alkalispirochaeta cellulosivorans gen. nov., sp. nov. is proposed. The type strain of Alkalispirochaeta cellulosivorans is JC227T (=KCTC 15343T=NBRC 110105T). We also propose the reclassification of Spirochaeta sphaeroplastigenens, Spirochaeta odontotermitis, Spirochaeta alkalica and Spirochaeta americana as Alkalispirochaeta sphaeroplastigenens comb. nov. (type strain JC133T=KCTC 15220T=NBRC 109056T), Alkalispirochaeta odontotermitis comb. nov. (type strain JC202T=KCTC 15324T=NBRC 110104T), Alkalispirochaeta alkalica comb. nov. (type strain Z-7491T=DSM 8900T=ATCC 700262T) and Alkalispirochaeta americana comb. nov. (type strain ASpG1T=ATCC BAA-392T=DSM 14872T). The type species of Alkalispirochaeta gen. nov. is Alkalispirochaeta alkalica comb. nov.
authors.affiliation: Bacterial Discovery Laboratory, Centre for Environment, Institute of Science and Technology, J. N. T. University Hyderabad, Kukatpally, Hyderabad 500 085, India.
authors.forename: T
authors.initials: T
authors.lastname: Sravanthi
authors.affiliation: Department of Plant Sciences, School of Life Sciences, University of Hyderabad, P.O. Central University, Hyderabad 500 046, India.
authors.forename: L
authors.initials: L
authors.lastname: Tushar
authors.affiliation: Bacterial Discovery Laboratory, Centre for Environment, Institute of Science and Technology, J. N. T. University Hyderabad, Kukatpally, Hyderabad 500 085, India.
authors.forename: Ch
authors.initials: C
authors.lastname: Sasikala
authors.affiliation: Department of Plant Sciences, School of Life Sciences, University of Hyderabad, P.O. Central University, Hyderabad 500 046, India.
authors.forename: Ch V
authors.initials: CV
authors.lastname: Ramana
mesh_terms: D000818:Animals; D015373:Bacterial Typing Techniques; D001482:Base Composition; D002482:Cellulose / Q000378:metabolism; D003058:Cockroaches / Q000382:microbiology*; D004269:DNA, Bacterial / Q000235:genetics; D005227:Fatty Acids / Q000737:chemistry; D007194:India; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D010743:Phospholipids / Q000737:chemistry; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D013142:Spirochaeta / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D014934:Wood
chemical_list: D004269:DNA, Bacterial; D005227:Fatty Acids; D010743:Phospholipids; D012336:RNA, Ribosomal, 16S; D002482:Cellulose