Draft genome sequence of Halomonas lutea strain YIM 91125(T) (DSM 23508(T)) isolated from the alkaline Lake Ebinur in Northwest China

Abstract

Species of the genus Halomonas are halophilic and their flexible adaption to changes of salinity and temperature brings considerable potential biotechnology applications, such as degradation of organic pollutants and enzyme production. The type strain Halomonas lutea YIM 91125(T) was isolated from a hypersaline lake in China. The genome of strain YIM 91125(T) becomes the twelfth species sequenced in Halomonas, and the thirteenth species sequenced in Halomonadaceae. We described the features of H. lutea YIM 91125(T), together with the high quality draft genome sequence and annotation of its type strain. The 4,533,090 bp long genome of strain YIM 91125(T) with its 4,284 protein-coding and 84 RNA genes is a part of Genomic Encyclopedia of Type Strains, Phase I: the one thousand microbial genomes (KMG-I) project. From the viewpoint of comparative genomics, H. lutea has a larger genome size and more specific genes, which indicated acquisition of function bringing better adaption to its environment. DDH analysis demonstrated that H. lutea is a distinctive species, and halophilic features and nitrogen metabolism related genes were discovered in its genome.

Keywords: Aerobic; Chemoorganotrophic; Gram-negative; Halomonas lutea; Lake Ebinur; Moderately halophilic.

Figure 1

Transmission electron micrograph of H. lutea YIM 91125 ^T .

Figure 2

Phylogenetic tree highlighting the position of H. lutea relative to the type strains of the other species within Halomonas. According to the most recent release of the EzTaxon-e database, all the 16S rRNA gene sequences of the type strains within genus Halomonas were retained. The tree was inferred from 1,383 aligned bases [29] under the neighbor-joining (NJ) [30] and maximum-likelihood (ML) [31] methods with 1,000 randomly selected bootstrap replicates using MEGA version 5.2 [32]. The branches are scaled in terms of the expected number of substitutions per site. Numbers adjacent to the branches are support values from 1,000 NJ bootstrap (left) and from 1,000 ML bootstrap (right) replicates [33] if they are larger than 50%. Lineages with type strain genome sequencing projects registered in Genomes OnLine Database (GOLD) [34] are labeled with one asterisk, and those have available genomic data are labeled with two asterisks. Non-type strain LS21of H. campaniensis and H. elongata DSM 2581^T listed ‘Complete and Published’ are also labeled with two asterisks.

Figure 3

Graphical map of the largest scaffold in Halomonas lutea YIM 91125^T. From bottom to the top: Genes on forward strand (colored by COG categories), Genes on reverse strand (colored by COG catergories), RNA genes (tRNA green, rRNA red, other RNAs black), GC content, GC skew (purpele/olive).

Figure 4

Distribution of functional classes of predicted genes in Halomonas species chromosomes according to the clusters of orthologous groups of proteins.