Kushneria pakistanensis sp. nov., a novel moderately halophilic bacterium isolated from rhizosphere of a plant (Saccharum spontaneum) growing in salt mines of the Karak area in Pakistan.

Abstract

The taxonomic position of a Gram-stain negative, moderately halophilic bacterium, designated NCCP-934(T), was investigated using polyphasic taxonomic approach. The strain NCCP-934(T) was isolated from rhizosphere of a plant (Saccharum spontaneum, family Poaceae) growing in salt mines area in the Karak district of Khyber Pakhtunkhwa Province, Pakistan. Cells of strain NCCP-934(T) are rod shaped and motile. The bacterium is strictly aerobic, can grow at a temperature range of 10-40°C (optimum at 30-33°C) and in a pH range of 6.0-10.5 (optimum pH 7.0-9.0). The strain can tolerate 1-30% (w/v) NaCl (optimal growth occurs in the presence of approximately 3-9% NaCl). The phylogenetic analysis based on the 16S rRNA gene sequence, showed that strain NCCP-934(T) belongs to the genus Kushneria with the highest sequence similarity to K. marisflavi SW32(T) (98.9%), K. indalinina CG2.1(T) (98.7%), K. avicenniae MW2a(T) (98.4%) and less than 97% similarity with other related species (94.7% with the type species of the genus, K. aurantia A10(T)). DNA-DNA relatedness between strain NCCP-934(T) and the type strains of the closely related species was lower than 18%. The chemotaxonomic data (major respiratory quinone, Q9; predominant fatty acids, C18:1 ω7c and C16:0 followed by C12:0 3-OH and Summed features 3 (C16:1 ω7c/iso-C15:0 2-OH); major polar lipids, diphosphatidylglycerol, phosphatidylglycerol, phosphatidylmonomethylethanol, phosphatidylserine, phosphatidylinositol and three polar lipid of unknown structure) supported the affiliation of strain NCCP-934(T) within the genus Kushneria. The DNA G+C content of strain NCCP-934(T) was 59.2mol%. On the basis of phenotypic, chemotaxonomic and phylogenetic data, strain NCCP-934(T) can be distinguished from the closely related taxa and thus represents a novel species in the genus Kushneria, for which the name Kushneria pakistanensis sp. nov. is proposed, with the type strain NCCP-934(T) (=LMG 28525(T)=KCTC 42082(T)=JCM 18802(T)).