Gelidibacter maritimus sp. nov., isolated from marine sediment.

A Gram-stain-negative, yellow, strictly aerobic, non-flagellated, gliding, rod-shaped bacterial strain, was isolated from costal sediment, designated as F6074T. The strain F6074T grows optimally at 30 °C, pH 7.5, and 3.0% (w/v) NaCl. Cells of strain F6074T are 0.2-0.5 µm wide and 1.0-2.0 µm long. Phylogenetic analysis based on 16S rRNA gene sequence indicated that strain F6074T belonged to the genus Gelidibacter, with the highest sequence similarity to Gelidibacter japonicus JCM 31967T (98.0%), followed by G. flavus JCM 31135T (97.7%), and similarity between strain F6074T and the type species G. algens DSM 12408T was 96.0%. Genome sequencing results revealed a genome size of 47,07,621 bp. The DNA G + C content was 37.8 mol%. The ANI and dDDH values between strain F6074T and G. japonicus JCM 31967T were 83.9 and 27.8%, the values between strain F6074T and G. algens DSM 12408T were 77.5% and 31.5%, and the values between strain F6074T and G. flavus JCM 31135T were 84.3 and 27.9%, respectively. The predominant quinone was MK-6 and the major fatty acids were iso-C15:0, iso-C15:1G, iso-C17:0 3-OH, anteiso-C15:0 and summed feature 3. The polar lipids were consisted of phosphatidylethanolamine (PE), two unidentified aminolipids (AL) and three unidentified lipids (L1, L2, L3). Based on the phenotypic, phylogenetic and chemotaxonomic data, strain F6074T was considered to represent a novel species of the genus Gelidibacter, for which the name Gelidibacter maritimus sp. nov., is proposed. The type strain is F6074T (MCCC 1H00427T = KCTC 72942T).

Gelidibacter pelagius sp. nov., Isolated from Coastal Sediment.

A novel Gram-stain-negative, aerobic, rod-shaped, non-flagellated, and gliding bacterial strain, designated DF109T, was isolated from the coastal sediment of Jingzi Wharf, Weihai, China. The optimal growth occurs at 28°C, pH 7.0-7.5, and 1.0% (w/v) NaCl environment. The colony was yellow-colored, convex, non-transparent, and circular on 2216E Agar. Phylogenetic analyses of the 16S rRNA gene and genome sequence of this newly isolated strain revealed that it is a member of the genus Gelidibacter within the family Flavobacteriaceae. The phylogenetic analysis based on 16S rRNA gene sequences indicated that strain DF109T has the highest sequence similarity to Gelidibacter japonicus JCM 31967T (98.0%). The average nucleotide identity (ANI) values between genomes of DF109T and G. japonicus JCM 31967T and G. algens DSM 12408T were 86.3% and 78.7% and the digital DNA-DNA hybridization (dDDH) values were 31.4% and 22.4%, respectively. The sole isoprenoid quinone was MK-6 and the major cellular fatty acids were iso-C15:1G, iso-C17:0 3-OH, anteiso-C15:0, and iso-C16:0 3-OH. The major polar lipids of strain DF109T were an aminolipid, a phosphatidylethanolamine, and four unidentified lipids. The genomic DNA G+C content was 37.5 mol%. Strain DF109T is suggested to represent a novel species in the genus Gelidibacter, for which the name Gelidibacter pelagius sp. nov. is proposed. The type strain is DF109T (=MCCC 1H00454T=KCTC 82420T).

Tenacibaculum pelagium sp. nov., isolated from marine sediment.

A novel bright yellow pigmented, Gram-stain-negative, gliding, aerobic and rod-shaped marine bacterium, designated strain S7007T, was isolated from a marine sediment sample taken from Jingzi Wharf, Weihai, China. The bacterium was able to grow at 4-33 °C (optimum 28 °C), at pH 6.5-9.0 (optimum 7.0) and with 2.0-4.0% (w/v) NaCl (optimum 3.0%). According to the phylogenetic analysis based on the 16S rRNA gene sequences, strain S7007T was associated with the genus Tenacibaculum and showed highest similarity to Tenacibaculum adriaticum JCM 14633T (98.0%). The average nucleotide identity (ANI) scores of strain S7007T with T. adriaticum JCM 14633T and T. maritimum NBRC 110778T were 78.3% and 77.1%, respectively and the Genome-to-Genome Distance Calculator (dDDH) scores were 20.5% and 19.9%, respectively. The sole isoprenoid quinone was MK-6 and the major cellular fatty acids (> 10.0%) were iso-C15:0, iso-C15:0 3-OH, iso-C15: 1 G and summed feature 3 (comprising C16:1 ω7c and/or C16:1 ω6c). The major polar lipids of strain S7007T were phosphatidylethanolamine, phosphatidyldimethylethanolamine, one unidentified lipid and two unidentified aminolipids. The genomic DNA G + C content was 30.9 mol %. The combined phenotypic data and phylogenetic inference that strain S7007T should be classified as a novel species in the genus Tenacibaculum, for which the name Tenacibaculum pelagium sp. nov. is proposed. The type strain is S7007T (= MCCC 1H00428T = KCTC 72941T).

Chryseobacterium lacus sp. nov. Isolated From the Surface Water of Two Lakes With Light-Induced Carotenoid Production.

Two Gram-stain-negative, rod-shaped, gliding, catalase-positive, and facultative anaerobic strains, YLOS41T and XH07, were isolated from surface water of Yilong Lake and West Lake of Dali in Yunnan Province, respectively. Both strains were yellow-colored under light conditions and white-colored under dark conditions. The results of physiological and chemotaxonomic characterization, sequencing and phylogenetic analysis, and draft genome sequence comparison demonstrated that the two strains represented a single novel species within the genus Chryseobacterium, for which the name Chryseobacterium lacus sp. nov. is proposed. The type strain is YLOS41T (= KCTC 62352T = MCCC 1H00300T), and the second strain is XH07 (= KCTC 62993). During the cultivation process, we found that the colony color of the two strains changed from white to yellow with illumination. The study investigated the effects of light irradiation on the strain YLOS41T. Results showed that light irradiation did not affect the growth of cells but significantly increased carotenoid synthesis, which caused the change of colony color. In-depth metabolic analysis was conducted by transcriptome. The predominant changes were found for genes involved in carotenoid synthesis as protection from light damage. Based on the genome and transcriptome, we proved that strain YLOS41T possessed a complete synthetic pathway of carotenoid and speculated that the production was zeaxanthin. This was the first report of Chryseobacterium species with light-induced carotenoid synthesis. This study enhances our present knowledge on how Chryseobacterium species isolated from surface water responds to light damage.