Downloaded from www.microbiologyresearch.org by IP: 54.70.40.11 On: Sun, 16 Dec 2018 01:38:16 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. T. Sravanthi, 1 3 L. Tushar, 2 3 Ch. Sasikala 1 and Ch. V. Ramana 2 Correspondence Ch. Sasikala sasi449@yahoo.ie Ch. V. Ramana cvr449@gmail.com 1 Bacterial Discovery Laboratory, Centre for Environment, Institute of Science and Technology, J. N. T. University Hyderabad, Kukatpally, Hyderabad 500 085, India 2 Department of Plant Sciences, School of Life Sciences, University of Hyderabad, P.O. Central University, Hyderabad 500 046, India An obligately anaerobic spirochaete designated strain JC227 T was isolated from the gut of a wood-eating cockroach, Cryptocercus punctulatus (Scudder), from the Rann of Kutch, Gujarat, India. Strain JC227 T was Gram-stain-negative, mesophilic, halotolerant and alkaliphilic. Based on 16S rRNA gene sequence analysis, strain JC227 T belongs to the genus Spirochaeta, with Spirochaeta sphaeroplastigenens JC133 T (99.51 %), S. odontotermitis JC202 T (99.30 %), S. alkalica Z-7491 T (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 JC227 T and S. sphaeroplastigenens JC133 T , S. odontotermitis JC202 T , S. alkalica DSM 8900 T and S. americana DSM 14872 T was 62¡2, 63, 58¡2 and 48¡4 %, respectively. Strain JC227 T contained phosphatidylglycerol, diphosphatidylglycerol, an unidentified glycolipid and six unidentified lipids. Summed feature C 18 : 1 v7c/C 18 : 1 v6c was the predominant cellular fatty acid, with significant proportions of C 16 : 0 ,C 14 : 0 ,C 12 : 0 ,C 15 : 1 v6c,C 16 : 1 v5c, C 16 : 1 v6c/C 16 : 1 v7c and C 17 : 0 2-OH. The DNA G+C content of strain JC227 T was 55.5 mol%. On the basis of physiological, biochemical, chemotaxonomic (including metabolomic) and genomic differences from previously described taxa, strain JC227 T 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 JC227 T (5KCTC 15343 T 5NBRC 110105 T ). We also propose the reclassification of Spirochaeta sphaeroplastigenens, Spirochaeta odontotermitis, Spirochaeta alkalica and Spirochaeta americana as Alkalispirochaeta sphaeroplastigenens comb. nov. (type strain JC133 T 5KCTC 15220 T 5NBRC 109056 T ), Alkalispirochaeta odontotermitis comb. nov. (type strain JC202 T 5KCTC 15324 T 5NBRC 110104 T ), Alkalispirochaeta alkalica comb. nov. (type strain Z-7491 T 5DSM 8900 T 5ATCC 700262 T ) and Alkalispirochaeta americana comb. nov. (type strain ASpG1 T 5ATCC BAA-392 T 5DSM 14872 T ). The type species of Alkalispirochaeta gen. nov. is Alkalispirochaeta alkalica comb. nov. Symbiotic spirochaetes are interesting for two major reasons. First, they are key players in carbon recycling, par- ticularly in the degradation of lignocellulose along with other gut micro-organisms (Berlanga et al., 2007), and second, they are not well characterized taxonomically, since the majority are putative taxa identified through metagenomics (Ohkuma et al., 1999; Shivani et al., 2015; 3These authors contributed equally to this work. The GenBank/EMBL/DDBJ accession number for the 16S rRNA gene sequence of strain JC227 T is HG531387. Four supplementary figures and a supplementary table are available with the online Supplementary Material. International Journal of Systematic and Evolutionary Microbiology (2016), 66, 1612–1619 DOI 10.1099/ijsem.0.000865 000865 G 2016 IUMS Printed in Great Britain 1612