Egicoccus halophilus gen. nov., sp. nov., a halophilic, alkalitolerant actinobacterium and proposal of Egicoccaceae fam. nov. and Egicoccales ord. nov

Int J Syst Evol Microbiol. 2016 Feb;66(2):530-535. doi: 10.1099/ijsem.0.000749. Epub 2015 Nov 6.

Abstract

A novel Gram-stain-positive, non-motile, moderately halophilic and alkalitolerant actinobacterium, designated EGI 80432T, was isolated from a saline-alkaline soil of Xinjiang province, north-west China. Cells were non-endospore-forming cocci with a diameter of 0.5-0.8 μm. Strain EGI 80432T grew in the presence of 0-9 % (w/v) NaCl (optimum at 3-5 %), and also grew within the pH range 6.0-10.0 (optimum at pH 8.0-9.0) on marine 2216E medium. The peptidoglycan type was A1γ. The whole-cell hydrolysates contained glucose, galactose, mannose and three unknown sugars as major sugars. The predominant menaquinone was MK-9(H4). The major fatty acids were C17 : 1ω8c, summed feature 3 (C16 : 1ω7c/C16 : 1ω6c), C18 : 1ω9c and iso-C15 : 0 The polar lipids comprised diphosphatidylglycerol, phosphatidylglycerol, one unknown phosphoglycolipid, three unknown phospholipids and four unknown polar lipids. The genomic DNA G+C content was 75.2 mol%. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain EGI 80432T clustered within the radius of the class Nitriliruptoria. Levels of sequence similarity between strain EGI 80432T and its phylogenetic neighbours Nitriliruptor alkaliphilus ANL-iso2T and Euzebya tangerina F10T were 94.1 and 88.1 %, respectively. Based on morphological, physiological and chemotaxonomic characteristics and phylogenetic analysis, a novel species of a new genus, Egicoccus halophilus gen. nov., sp. nov., is proposed, within the new family and new order Egicoccaceae fam. nov. and Egicoccales ord. nov. in the class Nitriliruptoria. The type strain of Egicoccus halophilus is EGI 80432T ( = CGMCC 1.14988T = KCTC 33612T).

MeSH terms

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

Substances

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