Paenibacillus selenitireducens sp. nov., a selenite-reducing bacterium isolated from a selenium mineral soil

Abstract

A Gram-stain-positive, rod-shaped, facultatively anaerobic bacterium, designated strain ES3-24(T), was isolated from a selenium mineral soil. The isolate was endospore-forming, nitrate-reducing and motile by means of peritrichous flagella. The major menaquinone was menaquinone 7 (MK-7) and the predominant fatty acids (>5%) were anteiso-C15:0, iso-C16:0, C16:0 and anteiso-C17:0. The major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine and two unknown aminophospholipids. Strain ES3-24(T) contained meso-diaminopimelic acid in the cell-wall peptidoglycan and the DNA G+C content was 49.6 mol%. According to phylogenetic analysis based on the 16S rRNA gene sequence, strain ES3-24(T) was most closely related to Paenibacillus terrigena A35(T), with 16S rRNA gene sequence identity of 98.3%, while the other members of the genus Paenibacillus had 16S rRNA gene sequence identities of less than 95.0%. DNA-DNA relatedness between strain ES3-24(T) and P. terrigena CCTCC AB206026(T) was 39.3 %. In addition, strain ES3-24(T) showed obvious differences from closely related species in major polar lipids, nitrate reduction and other physiological and biochemical characteristics. The data from our polyphasic taxonomic study reveal that strain ES3-24(T) represents a novel species of the genus Paenibacillus, for which the name Paenibacillus selenitireducens sp. nov. is proposed. The type strain is ES3-24(T) ( = KCTC 33157(T) = CCTCC AB2013097(T)).