Gracilibacillus alcaliphilus sp. nov., a facultative alkaliphile isolated from indigo fermentation liquor for dyeing

Int J Syst Evol Microbiol. 2014 Sep;64(Pt 9):3174-3180. doi: 10.1099/ijs.0.060871-0. Epub 2014 Jun 24.


A facultatively alkaliphilic, lactic-acid-producing and halophilic strain, designated SG103(T), was isolated from a fermented Polygonum indigo (Polygonum tinctorium Lour.) liquor sample for dyeing prepared in a laboratory. 16S rRNA gene sequence phylogeny suggested that SG103(T) is a member of the genus Gracilibacillus with the closest relatives being 'Gracilibacillus xinjiangensis' J2 (similarity: 97.06 %), Gracilibacillus thailandensis TP2-8(T) (97.06 %) and Gracilibacillus halotolerans NN(T) (96.87 %). Cells of the isolate stained Gram-positive and were facultatively anaerobic straight rods that were motile by peritrichous flagella. The strain grew at temperatures between 13 and 48 °C with the optimum at 39 °C. It grew in the range pH 7-10 with the optimum at pH 9. The isoprenoid quinone detected was menaquinone-7 (MK-7) and the DNA G+C content was 41.3 mol%. The whole-cell fatty acid profile mainly (>10 %) consisted of iso-C15 : 0, anteiso-C15 : 0 and anteiso-C17 : 0. Unlike other reported species of the genus Gracilibacillus, the strain lacked diphosphatidylglycerol as a major polar lipid. DNA-DNA hybridization experiments with strains exhibiting greater than 96.87 % 16S rRNA gene sequence similarity, 'G. xinjiangensis' J2, G. thailandensis TP2-8(T) and G. halotolerans NN(T), revealed 2±4 %, 4±9 % and 3±2 % relatedness, respectively. On the basis of the differences in phenotypic and chemotaxonomic characteristics, and the results of phylogenetic analyses based on 16S rRNA gene sequences and DNA-DNA relatedness data from reported species of the genus Gracilibacillus, strain SG103(T) merits classification as a members of a novel species, for which the name Gracilibacillus alcaliphilus sp. nov. is proposed. The type strain is SG103(T) ( = JCM 17253(T) = NCIMB 14683(T)).

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacillaceae / classification*
  • Bacillaceae / genetics
  • Bacillaceae / isolation & purification
  • Bacterial Typing Techniques
  • Base Composition
  • Coloring Agents
  • DNA, Bacterial / genetics
  • Fatty Acids / chemistry
  • Fermentation
  • Indigo Carmine*
  • Molecular Sequence Data
  • Nucleic Acid Hybridization
  • Phylogeny*
  • Polygonum / microbiology*
  • RNA, Ribosomal, 16S / genetics
  • Sequence Analysis, DNA
  • Vitamin K 2 / analogs & derivatives
  • Vitamin K 2 / chemistry


  • Coloring Agents
  • DNA, Bacterial
  • Fatty Acids
  • RNA, Ribosomal, 16S
  • Vitamin K 2
  • menaquinone 7
  • Indigo Carmine

Associated data

  • GENBANK/AB854047