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

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 SDU3-1(T), and two rose pink strains, designated SDU13 and SDU14(T), 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 SDU14(T) formed solitary sporangioles under starvation conditions, while SDU3-1(T) had no fruiting body structures. They showed 95.9-97.0% (SDU3-1(T)) or 98.7-98.9% (SDU13 and SDU14(T)) 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 (SDU3-1(T)), 13.9 Mbp (SDU13) and 13.8 Mbp (SDU14(T) ) 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 C-18(.1)omega 9C, C-16(:0) and C-18(: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 SDU3-1(T) (=CGMCC 1.16875(T) = KCTC 72136(T)) and SDU14(T) (=CCTCC AB 2021123(T) = KCTC 82625(T)), respectively. (C) 2021 Elsevier GmbH. All rights reserved.

Automated summary

The three strains of Polyangium isolated from soil samples display unique characteristics such as aerobic growth, mesophilic properties, lack of salt tolerance, and predation on living microorganisms. Their genome sequences show phylogenetic separation from traditional Polyangium species, indicating the presence of two new species within the genus.