Leucobacter edaphi sp. nov., a highly chromate-tolerant bacterium isolated from chromium containing chemical plant soil

Antonie Van Leeuwenhoek. 2023 Dec;116(12):1433-1445. doi: 10.1007/s10482-023-01895-0. Epub 2023 Oct 24.

Abstract

A Gram-positive, aerobic, rod-shaped non-motile, non-sporulating bacterium, designated CSA2T, was isolated from chromium-containing soils collected from a chemical plant. The 16S rRNA gene sequence of strain CSA2T showed the highest homology with Leucobacter chromiireducens subsp. solipictus (97.85%), Leucobacter chromiireducens subsp. chromiireducens (97.85%). The digital DNA-DNA hybridization (dDDH), average nucleotide identity (ANI) and the amino acid identity (AAI) values among strains CSA2T and the selected Leucobacter species were 20.6-23.4% (dDDH), 72.67-78.03% (ANI) and 66.39-76.16% (AAI), falling below the recommended thresholds for species delimitation. The principal fatty acids were anteiso-C15:0, iso-C16:0 and anteiso-C17:0. The polar lipids were phosphatidylglycerol, diphosphatidylglycerol and an unknown glycolipid. The major menaquinones detected were MK-10 and MK-11. The cell-wall amino acids included 2,4-diaminobutyric acid, threonine, glutamic acid, alanine and glycine. Based on molecular feature, phenotypic and chemotaxonomic, strain CSA2T was considered to be a novel species of the genus Leucobacter., and the name Leucobacter edaphi sp. nov. is proposed. The type strain is CSA2T (= JCM 34360T = CGMCC 1.18747T).

Keywords: Chromium resistance; Chromium soil; Leucobacter; Leucobacter edaphi; Novel species.

MeSH terms

  • Actinobacteria*
  • Actinomycetales*
  • Amino Acids
  • Bacterial Typing Techniques
  • Chromates*
  • Chromium
  • DNA
  • DNA, Bacterial / chemistry
  • DNA, Bacterial / genetics
  • Fatty Acids / analysis
  • Phospholipids / analysis
  • Phylogeny
  • RNA, Ribosomal, 16S / genetics
  • Sequence Analysis, DNA

Substances

  • Chromates
  • Chromium
  • RNA, Ribosomal, 16S
  • Fatty Acids
  • Amino Acids
  • DNA
  • DNA, Bacterial
  • Phospholipids

Supplementary concepts

  • Leucobacter chromiireducens subsp. solipictus
  • Leucobacter chromiireducens subsp. chromiireducens