Planctomonas psychrotolerans sp. nov., isolated from rhizosphere soil of Suaeda salsa

Abstract

A psychrotolerant actinobacterium, designated strain J5903T, was isolated from an alkaline soil sample from the rhizosphere of Suaeda salsa collected in desertification land surrounding Jiuliancheng Nur in Hebei Province, PR China. Cells of the isolate were Gram-stain-positive, aerobic, non-motile and non-spore-forming cocci. Strain J5903T grew optimally at 20‒25 °C, at pH 7.0‒7.5 and with <1 % (w/v) NaCl. The cell-wall peptidoglycan type was B2γ with d-2,4-diaminobutyric acid and l-2,4-diaminobutyric acid as diagnostic amino acids. The muramyl residue was acetyl type. The menaquinones were MK-11, MK-12, MK-10 and MK-13. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol and one unidentified glycolipid. The major whole-cell fatty acids were anteiso-C15 : 0, iso-C16 : 0 and anteiso-C17 : 0. The genomic DNA G+C content was 69.1 mol%. It shared the highest average nucleotide identity and digital DNA-DNA hybridization values with Planctomonas deserti 13S1-3T. Phylogenies based on genome sequence showed that strain J5903T and P. deserti 13S1-3T formed a robust cluster with high bootstrap support. Strain J5903T shared typical chemotaxonomic characteristics with P. deserti 13S1-3T. Combining the polyphasic taxonomic evidence, strain J5903T represents a novel species of the genus Planctomonas, for which the name Planctomonas psychrotolerans sp. nov. is proposed. The type strain is J5903T (=DSM 101894T=CGMCC 1.15523T).