Polyphasic characterization of the thermotolerant cyanobacterium Desertifilum sp. strain IPPAS B-1220

FEMS Microbiol Lett. 2017 Feb 1;364(4). doi: 10.1093/femsle/fnx027.

Abstract

A cyanobacterial strain from Lake Shar-Nuur, a freshwater lake in Mongolia, was isolated and characterized by a polyphasic approach. According to the 16S ribosomal RNA gene sequence, this strain (IPPAS B-1220) belongs to a newly described genus Desertifilum. In general, strains of Desertifilum maintain their genetic stability, as seen from the analysis of the 16S rRNA gene and 16S-23S rRNA internal transcribed spacer sequences from strains collected at distant locations. The newly discovered strain is characterized by an unusual fatty acid composition (16:1Δ7 and 16:2Δ7,10). Analysis of its draft genomic sequence reveals the presence of six genes for the acyl-lipid desaturases: two Δ9-desaturases, desC1 and desC2; two Δ12-desaturases, desA1 and desA2; one desaturase of unknown specificity, desX; and one gene for the bacillary-type desaturase, desG, which supposedly encodes an ω9-desaturase. A scheme for a fatty acid desaturation pathway that describes the biosynthesis of 16:1Δ7 and 16:2Δ7,10 fatty acids in Desertifilum is proposed.

Keywords: Desertifilum; fatty acid desaturases; fatty acids; molecular phylogeny; polyphasic approach; ultrastructure.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Typing Techniques
  • Cyanobacteria / chemistry
  • Cyanobacteria / classification
  • Cyanobacteria / genetics*
  • Cyanobacteria / physiology*
  • DNA, Bacterial / genetics
  • Fatty Acid Desaturases / genetics
  • Fatty Acids / chemistry
  • Fresh Water / microbiology
  • Lakes / microbiology
  • Phylogeny
  • RNA, Ribosomal, 16S / genetics
  • Sequence Analysis, DNA
  • Thermotolerance*

Substances

  • DNA, Bacterial
  • Fatty Acids
  • RNA, Ribosomal, 16S
  • Fatty Acid Desaturases