Two new Polyangium species, P. aurulentum sp. nov. and P. jinanense sp. nov., isolated from a soil sample

Abstract

Polyangium belongs to Polyangiaceae family of Myxococcales, a taxonomic group well-known for their extraordinary social lifestyle and diverse novel gene clusters of secondary metabolites. A yellow-golden strain, designated SDU3-1T, and two rose pink strains, designated SDU13 and SDU14T, were isolated from a soil sample. These three strains were aerobic, mesophilic, not salt-tolerant and were able to prey on living microorganisms. SDU13 and SDU14T formed solitary sporangioles under starvation conditions, while SDU3-1T had no fruiting body structures. They showed 95.9–97.0% (SDU3-1T) or 98.7–98.9% (SDU13 and SDU14T) 16S rRNA gene similarity with the type strains of Polyangium, but were phylogenetically separate from them based on the 16S rRNA gene and genome sequences. Their genomes were 12.3 Mbp (SDU3-1T), 13.9 Mbp (SDU13) and 13.8 Mbp (SDU14T) with the G + C content range of 68.3–69.4 mol%. The average nucleotide identity and DNA-DNA hybridization analyses of genomes further indicated that these three strains belonged to two new species in Polyangium. Their major fatty acids were C18:1ω9c, C16:0 and C18:0. The polyphasic taxonomic characterization suggest that the three strains represent two novel species in the genus Polyangium, for which the names Polyangium aurulentum sp. nov. and Polyangium jinanense sp. nov. are proposed, and the type strains are SDU3-1T (=CGMCC 1.16875T = KCTC 72136T) and SDU14T (=CCTCC AB 2021123T = KCTC 82625T), respectively.