Microbacterium stercoris sp. nov., an indole acetic acid-producing actinobacterium isolated from cow dung

Int J Syst Evol Microbiol. 2021 Nov;71(11). doi: 10.1099/ijsem.0.005099.


A novel growth-promoting and indole acetic acid-producing strain, designated NEAU-LLBT, was isolated from cow dung collected from Shangzhi, Heilongjiang Province, PR China. Cells of strain NEAU-LLBT were Gram-stain-positive, non-motile, aerobic and non-spore-forming. Phylogenetic analysis based on 16S rRNA gene sequence indicated that strain NEAU-LLBT belonged to the genus Microbacterium. Strain NEAU-LLBT had high 16S rRNA sequence similarities of 98.81 and 98.41 % to Microbacterium paludicola DSM 16915T and Microbacterium marinilacus DSM 18904T, and less than 98 % to other members of the genus Microbacterium. Chemotaxonomic characteristics showed that MK-11 and MK-12 were detected as the predominant menaquinones. The peptidoglycan contained glutamic acid, aspartic acid, glycine, ornithine and a small amount of alanine, with ornithine as the diagnostic diamino acid. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol and an unidentified glycolipid. The major fatty acids were identified as anteiso-C15 : 0, iso-C16 : 0 and iso-C17 : 0. The genomic DNA G+C content of strain NEAU-LLBT was 70.2 mol%. In addition, the average nucleotide identity values between strain NEAU-LLBT and its reference strains, M. paludicola DSM 16915T, M. marinilacus DSM 18904T and M. album SYSU D8007T, were found to be 81.1, 79.4 and 78.7 %, respectively, and the level of digital DNA-DNA hybridization between them were 23.8, 22.6 and 21.8 %, respectively. Based on the phenotypic, phylogenetic and genotypic data, strain NEAU-LLBT is considered to represent a novel species of the genus Microbacterium, for which the name Microbacterium stercoris sp. nov is proposed, with NEAU-LLBT (=CCTCC AA 2018028T=JCM 32660T) as the type strain.

Keywords: Microbacterium stercoris sp. nov.; cow dung; indole acetic acid; polyphasic approach; whole genome.

MeSH terms

  • Animals
  • Bacterial Typing Techniques
  • Base Composition
  • Cattle / microbiology*
  • China
  • DNA, Bacterial / genetics
  • Fatty Acids* / chemistry
  • Feces / microbiology*
  • Indoleacetic Acids / metabolism*
  • Microbacterium* / classification
  • Microbacterium* / isolation & purification
  • Nucleic Acid Hybridization
  • Peptidoglycan / chemistry
  • Phospholipids / chemistry
  • Phylogeny*
  • RNA, Ribosomal, 16S / genetics
  • Sequence Analysis, DNA


  • DNA, Bacterial
  • Fatty Acids
  • Indoleacetic Acids
  • Peptidoglycan
  • Phospholipids
  • RNA, Ribosomal, 16S
  • indoleacetic acid