Draft Genome Sequences of Tersicoccus phoenicis DSM 30849T, Isolated from a Cleanroom for Spacecraft Assembly, and Tersicoccus sp. Strain Bi-70, Isolated from a Freshwater Lake.

Here, we report the draft genome sequences of Tersicoccus phoenicis DSM 30849T, isolated from a spacecraft assembly cleanroom at the National Aeronautics and Space Administration (NASA), and Tersicoccus sp. strain Bi-70, isolated from Lake Biwa, the largest lake in Japan. These genome sequences facilitate our understanding of the adaptation of these closely related strains to different habitats.

GENOME ANNOUNCEMENT

Tersicoccus phoenicis DSM 30849T is an aerobic Gram-positive bacterium belonging to the phylum Actinobacteria. It was first isolated from a National Aeronautics and Space Administration (NASA) spacecraft cleanroom which was thought to be biologically contaminant free (1). On the other hand, Tersicoccus sp. strain Bi-70 NBRC 112423 was isolated from Lake Biwa, the largest lake in Japan. Currently, the genus Tersicoccus includes two described species, T. phoenicis (type strain, DSM 30849T) and Tersicoccus solisilvae (KCTC 33776T), which was isolated from forest soil (2).

The genomic DNA of both strains was extracted using phenol-chloroform and ethanol precipitation (3). The Kapa HyperPlus kit (Kapa Biosystems) was used for library preparation, and paired-end sequences (300 bp of each end) were obtained on the MiSeq instrument with the MiSeq reagent kit version 3 (Illumina). Genome assembly was performed using Platanus version 1.2.4 (4). The assembled sequences were annotated using the NCBI Prokaryotic Genome Annotation Pipeline (PGAP) (5) and reviewed with the RAST version 2.0 (http://rast.nmpdr.org). The 16S rRNA gene sequence taxonomic identification using EzTaxon (6) confirmed that strain Bi-70 is most closely related to Tersicoccus phoenicis DSM 30849T (98.8% identity). The genome sequences of T. phoenicis DSM 30849T and Tersicoccus sp. Bi-70 consist of 132 and 19 scaffolds (total length, 3,210,299 bp and 3,479,893 bp; and N50, 108,378 bp and 556,029 bp, respectively) with median read coverages of 49.1 and 118.0×, respectively. The estimated genome sizes of both strains were smaller than those of sequenced strains belonging to the genus Arthrobacter, which is the closest relative of the genus Tersicoccus (e.g., 5.20 Mbp for A. crystallopoietes DSM 20117T [accession no. GCA_900100805.1] and 4.95 Mbp for A. globiformis NBRC 12137T [GCA_000238915.2]), and the G+C contents (DSM 30849T, 70.7%; Bi-70, 71.8%) were significantly higher than those of the Arthrobacter strains (DSM 20117T, 64.4%; NBRC 12137T, 66.2%).

For Tersicoccus sp. Bi-70, the PGAP identified 3,185 genes, including 3,128 protein-coding sequences (CDSs), 46 tRNA and three noncoding RNA genes, and 104 pseudogenes. The RAST annotation also identified a similar number of CDSs (3,204 CDSs). For T. phoenicis DSM 30849T, and the PGAP identified 3,088 genes, including 3,025 CDSs (2,991 CDSs by RAST), 46 tRNA and three noncoding RNA genes, and 152 pseudogenes.

The results of the RAST annotation showed that strains DSM 30849T and Bi-70 possess only four and three ion acquisition and metabolism-related genes, respectively. The numbers of genes for these categories are much lower than those in the members of the genus Arthrobacter (26 in A. crystallopoietes DSM 20117T and 22 in A. globiformis NBRC 12137T). However, despite the smaller genome size, the genus Tersicoccus has a nearly equivalent number of genes for other categories, e.g., 83 (DSM 30849T) and 91 (Bi-70) genes for the category of cell wall and capsule were identified in the Tersicoccus strains, while 104 (DSM 20117T) and 92 (NBRC 12137T) genes were identified in the Arthrobacter strains. The smaller genome sizes, the higher G+C contents, and the reduced numbers of ion acquisition and metabolism-related genes are the most characteristic features between members of the genera Tersicoccus and Arthrobacter. More detailed comparative analysis of the two Tersicoccus genomes will provide insights into the physiology and mechanisms of the adaptation to different environments.

Accession number(s).

The whole-genome shotgun projects of Tersicoccus phoenicis DSM 30849T and Tersicoccus sp. Bi-70 NBRC 112423 have been deposited in DDBJ/EMBL/GenBank under the accession numbers MRDE00000000 and MIEU00000000, respectively. The versions described in this paper are the first versions, MRDE01000000 and MIEU01000000.