Steptomyces fagopyri sp. nov., a novel actinomycete isolated from rhizospheric soil of Fagopyrum dibotrys

Int J Syst Evol Microbiol. 2020 Dec;70(12):6437-6443. doi: 10.1099/ijsem.0.004555.

Abstract

A novel actinomycete, designated strain QMT-28T, was isolated from rhizosphere soil of Fagopyrum dibotrys collected from Shuangfeng, Hunan Province, PR China. Strain QMT-28T grew well on International Streptomyces Project series media and formed well-developed, branched substrate hyphae and aerial mycelium that differentiated into loose spiral spore chains consisting of cylindrical spores with smooth surfaces. The diagnostic diamino acid was ll-diaminopimelic acid and the whole-cell sugars were galactose and glucose. The predominant fatty acids were C18 : 1 cis9, summed feature 6 (C18 : 2 cis 9,12/C18 : 0 a) and C16 : 0. The polar lipids included diphosphatidylglycerol, hydroxy phospatidylethanolamine, phosphatidylethanolamine, phosphatidylinositol, phosphatidylinositol mannosides, phospholipids of unknown structure containing glucosamine and several unidentified phospholipids. The major menaquinones were MK-9, MK-9(H2), MK-9(H4), MK-9(H6) and MK-9(H8). The genome size of strain QMT-28T was about 8.7 Mbp with a G+C content of 71.2 mol%. Phylogenetic analysis showed that the novel strain was closely related to Streptomyces olivochromogenes DSM 40451T (99.5 % similarity), Streptomyces mirabilis NBRC 13450T (98.9 %), Streptomyces kanamyceticus NBRC 13414T (98.9 %), Streptomyces kaempferi I37T (98.9 %) and Streptomyces arcticus ZLN234T (98.8 %). However, the average nucleotide identity values, the digital DNA-DNA hybridization values and the multilocus sequence analysis evolutionary distances between this strain and closely related strains showed that it belonged to a distinct species. In addition, these results were also supported by differences in the phenotypic characteristics between QMT-28T and five closely related type strains. Consequently, strain QMT-28T should represent a novel species of the genus Streptomyces, with the suggested name Streptomyces fagopyri sp. nov. The type strain is QMT-28T (=CICC 24808T=JCM 33796T).

Keywords: Streptomyces fagopyri sp. nov.; polyphasic taxonomy; rhizosphere soil.

MeSH terms

  • Bacterial Typing Techniques
  • Base Composition
  • China
  • DNA, Bacterial / genetics
  • Fagopyrum / microbiology*
  • Fatty Acids / chemistry
  • Genome Size
  • Nucleic Acid Hybridization
  • Phospholipids / chemistry
  • Phylogeny*
  • RNA, Ribosomal, 16S / genetics
  • Rhizosphere
  • Sequence Analysis, DNA
  • Soil Microbiology*
  • Streptomyces / classification*
  • Streptomyces / isolation & purification
  • Vitamin K 2 / analogs & derivatives
  • Vitamin K 2 / chemistry

Substances

  • DNA, Bacterial
  • Fatty Acids
  • Phospholipids
  • RNA, Ribosomal, 16S
  • Vitamin K 2
  • menaquinone 9