Deefgea salmonis sp. nov., isolated from gills of rainbow trout (Oncorhynchus mykiss)

Abstract

A Gram-stain-negative, milky white, aerobic, rod-shaped bacterium named strain H3-26^T was isolated from gills of Oncorhynchus mykiss in Lhasa, Tibet Autonomous Region, PR China. Strain H3-26^T grew at 4-30 °C and pH 5.0-11.0 (optimum, 25 °C and pH 7.0) with 0-1% (w/v) NaCl (optimum, 0%). The 16S rRNA gene sequence of strain H3-26^T showed the highest similarity to Deefgea rivuli WB 3.4-79^T (98.42%), followed by Deefgea chitinilytica Nsw-4^T (96.91%). Phylogenetic analysis based on 16S rRNA genes indicated that strain H3-26^T was a new member of the genus Deefgea. The digital DNA-DNA hybridization and average nucleotide identity values between the genome sequence of strain H3-26^T and Deefgea spp. were 21.2-21.9% and 76.3-77.4%, respectively. The genomic DNA G+C content of strain H3-26^T was 48.74%. The predominant fatty acids were C_12:0, C_14:0, C_16:0 and C_16:1 ω7c. Based on phenotypic, phylogenetic, and genotypic data, strain H3-26^T is considered to represent a novel species of the genus Deefgea, for which the name Deefgea salmonis sp. nov. is proposed. The type strain is H3-26^T (= JCM 35050^T = CICC 25103^T).

Keywords: Comparative genomics; Deefgea; Oncorhynchus mykiss; Tibet.