Gracilibacillus eburneus sp.nov., a moderately halophilic bacterium isolated from Xinjiang province, China

Abstract

A novel Gram-staining positive, moderately halophilic, endospore-forming, motile, rod-shaped and strictly aerobic strain, designated YIM 93565, was isolated from a salt lake in Xinjiang province of China and subjected to a polyphasic taxonomic study. Strain YIM 93565 grew in the range of pH 6.0-9.0 (optimum pH 7.0), 10-45 °C (optimum 35-40 °C) and at salinities of 2-24% (w/v) NaCl (optimum 7-10%). Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain YIM 93565 clustered with members of the genera Gracilibacillus and form a clade with Gracilibacillus bigeumensis KCTC 13130 (95.6% similarity) and Gracilibacillus halophilus DSM 17856 (94.9%), which was well separated from others. The DNA G + C content of this novel strain was 36.8 mol%. The major fatty acids were anteiso-C, iso-C, C and anteiso-C and its polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol, one unidentified glycolipid and two unidentified phospholipids. The predominant menaquinone was MK-7. The cell-wall peptidoglycan was based on meso-diaminopimelic acid. Based on the results of phylogenetic, physiological and chemotaxonomic comparative analyses, the isolate is assigned to a novel species of the genus Gracilibacillus, for which the name Gracilibacillus eburneus sp. nov. is proposed, with the type strain YIM 93565 (= DSM 23710 = CCTCC AB 2013249).

Gracilibacillus suaedae sp. nov., an indole acetic acid-producing endophyte isolated from a root of Suaeda salsa

“…The assembled genome completeness and contamination of the genomes were 99.3 and 1.2%, which meets the standards of genome data [45]. The genomic DNA G+C content was 36.7 mol%, which is within the range for Gracilibacillus species (35.0–43.0%) [9]. The ANIb and dDDH values of strain LD4P30 T to its closest relatives were lower than the delineation threshold values of 95–96 and 70% for identifying strains as different species [45] ().…”

“…The major respiratory quinone is MK-7 and the DNA G+C content ranges from 35.0 to 43.0 mol% [9]. The dominant fatty acids are iso-C 15:0 , anteiso-C 15:0 and anteiso-C 17:0 [9]. Most Gracilibacillus strains were isolated from salt lake water [4,6,8,[10][11][12].…”

“…The major polar lipids of the Gracilibacillus members are diphosphatidylglycerol and phosphatidylglycerol. The major respiratory quinone is MK-7 and the DNA G+C content ranges from 35.0 to 43.0 mol% [9]. The dominant fatty acids are iso-C 15:0 , anteiso-C 15:0 and anteiso-C 17:0 [9].…”

Propionibacterium freudenreichii CIRM-BIA 129 Osmoadaptation Coupled to Acid-Adaptation Increases Its Viability During Freeze-Drying

“…Thus, P. freudenreichii CIRM-BIA 129 responded to environmental stresses by modulating its membrane fluidity via the saturated/unsaturated ratio, with a profound increase of anteiso-C15:0, the main membrane fatty acid in P. freudenreichii (Thierry et al, 2011) and known to play a key role in bacterial stress adaptation (Annous et al, 1997). Anteiso-C15, a fatty acid abundant in halophilic bacteria (Guan et al, 2018; Jang et al, 2018; Ding et al, 2019), is accordingly increased under hyperosmotic conditions in halotolerant Gram-positive bacteria such as Planococcus sp. (Miller, 1985), Staphylococcus epidermidis (Komaratat and Kates, 1975), and S. aureus (Kanemasa et al, 1972).…”