Pontibacter ummariensis sp. nov., isolated from a hexachlorocyclohexane-contaminated soil

Abstract

A Gram-stain-negative, pinkish-red, rod-shaped bacterium designated strain NKM1^T was isolated from soil samples contaminated with hexachlorocyclohexane isomers, collected from Ummari village, Lucknow, Uttar Pradesh, India. The strain was characterized by a polyphasic taxonomic approach. 16S rRNA gene sequence analysis showed that strain NKM1^T clustered exclusively with members of the genus <i>Pontibacter</i> of the family <i>Cytophagaceae</i>, phylum <i>Bacteroidetes.</i> The 16S rRNA gene sequence similarity to type strains of the genus <i>Pontibacter</i> ranged from 96.7 to 93.8 %, with the highest sequence similarity found with <i>Pontibacter odishensis</i> JC130^T (96.7 %). Cells of strain NKM1^T were aerobic, non-flagellated and non-motile. Strain NKM1^T was catalase- and oxidase-positive but negative for nitrate reduction and hydrolysis of gelatin. The major fatty acids in strain NKM1^T were anteiso-C_{15 : 0}, iso-C_{15 : 0}, C_{16 : 0}, C_{18 : 1}ω9<i>c</i> and summed feature 3 (C_{16 : 1}ω7<i>c</i> and/or C_{16 : 1}ω6<i>c</i>). The polar lipid profile of strain NKM1^T showed the presence of phosphatidylethanolamine and unknown glycolipids as well as aminolipids. <i>sym-</i>Homospermidine was found to be the major polyamine and menaquinone 7 (MK-7) was the major respiratory quinone. The DNA G+C content of strain NKM1^T was determined to be 58.6 mol%. Based on phenotypic, chemotaxonomic, physiological and biochemical evidence, it is proposed that isolate NKM1^T represents a novel species that belongs to the genus <i>Pontibacter</i>, for which the name <i>Pontibacter ummariensis</i> sp. nov. is proposed. The type strain is NKM1^T ( = DSM 100161^T = KCTC 42944^T = MCC 2777^T).