Publications

4526

A highly salt-tolerant and alkaliphilic syntrophic consortium that degrades butyrate under sulfate-reducing conditions was purified from a hypersaline soda lake in southwest Siberia. Here, we present the complete genome sequence of the syntrophic primary butyrate degrader in order to understand the molecular mechanisms of interaction between consortium members.

The genus Pseudovibrio is commonly associated with marine invertebrates, which are essential for ocean health and marine nutrient cycling. Traditionally, the phylogeny of the genus has been based on 16S rRNA gene analysis. The use of the 16S rRNA gene or any other single marker gene for robust phylogenetic placement has recently been questioned. We used a large set of marker genes from all available Pseudovibrio genomes for in-depth phylogenomic analyses. We identified divergent monophyletic basal lineages within the Pseudovibrio genus, including two strains isolated from polyclad flatworms. These strains showed reduced sulfur metabolism and biosynthesis capacities. The phylogenomic analyses revealed distinct evolutionary trajectories and ecological adaptations that differentiate the divergent strains from the other Pseudovibrio members and suggest that they fall into a novel genus. Our data show the importance of widening the use of phylogenomics for better understanding bacterial physiology, phylogeny, and evolution.

A novel Gram-stain-positive, rod shaped and anaerobic bacterium, designated as W6T, was isolated from Shengli oilfield in China. Strain W6T was observed to grow from 20 to 45 °C with pH 6.5–9.0 (optimally at 40 °C and pH of 7.5) and without addition of NaCl. The major cellular fatty acids were iso-C15 : 0 (29.1%), C14 : 0 (27.0%) and C16 : 0 (12.2%), and the main polar lipids were lipids (L) and aminolipids (AL). The DNA G+C content is 42.9 mol%. Based on 16S rRNA gene sequence analysis, strain W6T showed highest similarities to Tissierella creatinini DSM 9508T (94.9%) and Soehngenia saccharolytica DSM 12858T (94.1%). The morphological, physiological, biochemical, phylogenetic and phylogenomic analyses demonstrated strain W6T (CCAM 534T=DSM 28124T=CGMCC 1.5291T) represents a novel species in a new genus, for which the name Gudongella oleilytica gen. nov. sp. nov. is proposed. The family Tissierellaceae is proposed as a new family containing the genera Anaerosalibacter , Gudongella, Keratinibaculum , Soehngenia , Sporanaerobacter , Tepidimicrobium , Tissierella , Urmitella and species Clostridium ultunense based on the phylogenetic and phylogenomic analyses.