The Polyphasic Taxonomic Identification Of Cytophagaceae Bacteria Fibrisoma Montanum HYT19~T

Microorganisms are widely spread in the earth's environment,most of which are not recognized and utilized by humans.In order to exploit the microbial resources of nature,we isolated,purified and identified 29 bacterial strains belonging to 18 genera from the soil of Danxia Mountain,Guangdong province in China.The 16S rRNA gene sequence of strain HYT19^T had the greatest similarity of 96.99%with that of the sole strain Fibrisoma limi BUZ 3^T in the genus Fibrisoma.In three phylogenetic trees constructed from 16S rRNA gene sequences,strain HYT19^T and strain BUZ 3^T always clustered into a clade.Cells of strain HYT19^T were Gram-stain-negative,aerobic,non-motile and rod-shaped.It grew at16oC-37oC?optimum 28oC-30oC?and at pH 6-7.The draft genome size of strain HYT19^T was 7.8 Mb with a DNA G+C content of 53.99 mol%.The digital DDH?dDDH?and average nucleotide identity?ANI?between strain HYT19^T and F.limi BUZ 3^T were 28.80%and 85.10%,respectively.MK-7 was the sole respiratory quinone.The major polar lipids were phosphatidylethanolamine,three unidentified aminophospholipids,three unidentified aminolipids and two unidentified lipids.The strain contained C_16:1?5c,iso-C_15:0,summed feature 3(C_16:1?6c and/or C_16:1?7c),C_16:0,iso-C_17:0 3-OH and anteiso-C_15:0 as the major fatty acids?>5%?.On the basis of phylogenetic,genomic,phenotypic and chemotaxonomic analysis,we propose a new species Fibrisoma montanum sp.nov.of genus Fibrisoma.The type strain is HYT19 ^T.In addition,the molecular mechanism of selenate transportation was investigated in Comamonas testosteroni S44.The phenotype of selenate reduction was disappeared when gene cysA coding ATPase responsible for sulfate transportation into cytoplasm was disrupted.This result showed that selenate was transported into cytoplasm through sulfate transporter in cell membrane and then selenate was reduced to selenium nanoparticles in cytoplasm.