Paenibacillus caui sp. nov., a nitrogen-fixing species isolated from the rhizosphere soil of a peach tree

Abstract

A nitrogen-fixing, endospore-forming, motile, rod-shaped, facultative aerobic bacterium, designated 81-11^T, was isolated from rhizosphere soil of a peach tree collected from Handan, Hebei, PR China. From the comparison of 16S rRNA gene sequence, the strain is most closely related to Paenibacillus phoenicis DSM 27463^T (96.9 %) and Paenibacillus faecis DSM 23593^T (96.7 %). The genome size of strain 81-11^T was 4.4 Mb, comprising 4879 predicted genes with a DNA G+C content of 50.0 mol%. The average nucleotide identity values of genome sequences between the novel isolate and the type strains of related species P. phoenicis DSM 27463^T and P. faecis DSM 23593^T were 71.8 and 72.1 %, respectively. The major cellular fatty acids were anteiso-C_{15 : 0}(47.8 %), iso-C_{16 : 0} (15.5 %) and iso-C_{15 : 0} (13.0 %). Menaquinone-7 was the major respiratory quinone. The polar lipids contained phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, aminophospholipid, aminoglycopid, unknown polar lipids and unidentified aminophosphoglycolipid. Based on phylogenetic, genomic and phenotypic characteristics, strain 81-11^T was classified as a novel species within the genus Paenibacillus, for which the name Paenibacillus caui sp. nov. is proposed. The type strain of Paenibacillus caui is 81-11^T (=JCM 34618^T=CGMCC 1.18907^T).

Keywords: 16SrRNA phylogeny; Paenibacillus caui; nitrogen-fixing bacteria; rhizospheres.