Actinophytocola gossypii sp. nov. and Streptomyces gossypii sp. nov., two novel actinomycetes isolated from rhizosphere soil of cotton

Abstract

Two Gram-positive, aerobic and non-motile actinomycetes, designated S1-96T and N2-109T, were isolated from soils collected from a cotton field. They are described as representing two novel species of genera Actinophytocola and Streptomyces through a polyphasic approach. Analysis of 16S rRNA gene sequences revealed that strains S1-96T and N2-109T showed highest similarity to Actinophytocola xinjiangensis CGMCC 4.4663T (99.10 %) and Streptomyces iconiensis BNT558T (98.21 %), respectively. Phylogenetic analyses based on 16S rRNA and core genes confirmed the close relationships of these strains. Genomic analyses further supported the novel taxonomic delimitation of these two species based on digital DNA–DNA hybridization and average nucleotide identity. Strains S1-96T and N2-109T contained MK-9(H4) and MK-9(H6) as the most abundant menaquinone, respectively. High abundances of iso-fatty acids were detected in both strains, which was similar to their close relatives. Physiological and polar lipid analyses also revealed differences between these strains and their phylogenetic neighbours, supporting their taxonomic delimitation as novel species. The names Actinophytocola gossypii sp. nov. (type strain S1-96T=JCM 34412T=CGMCC 4.7707T) and Streptomyces gossypii sp. nov. (type strain N2-109T=JCM 34628T=CGMCC 4.7717T) are proposed.