Metabacillus sediminilitoris sp. nov., a marine bacterium isolated from a tidal sediment

Metabacillus rhizolycopersici sp. nov., Isolated from the Rhizosphere Soil of Tomato Plants

A Gram-positive, endospore-forming, rod-shaped and aerobic bacterium, with swarming and swimming motility, designated strain DBTR6^T, was isolated from the rhizosphere soil of tomato plants. Strain DBTR6^T grew at 20-45 ℃ (optimum 30-37℃), pH 4-9 (optimum 7-8) and at salinities from 0 to 5% (optimum 1%). Phylogenetic analysis using 16S rRNA gene sequences showed this strain belonged to the genus Metabacillus and was most closely related to Metabacillus litoralis DSM 16303 ^T (98.3%) and Metabacillus sediminilitoris MCCC 1K03777^T (98.3%). The DNA G + C content of the genomic DNA was 36.4%. The digital DNA-DNA hybridization value between strain DBTR6^T and reference strains M. sediminilitoris MCCC 1K03777^T and "M. bambusae" BG109^T were less than 70% (26.7% and 26.0%), and the average nucleotide identity score were less than 95% (78.55% and 78.38%), and the Amino Acid Identity values calculated were less than 96% (79.99% and 80.18%), respectively, suggesting that strain DBTR6^T represented a novel species in the genus Metabacillus. Chemotaxonomic analysis showed that strain DBTR6^T contained MK-7 as the major respiratory quinone. The predominant fatty acids (> 10.0%) were iso-C_15:0, anteiso-C_15:0 and C_16:0. The major polar lipids were diphosphatidylglycerol (DPG), phosphatidylethanolamine (PE), phosphatidylglycerol (PG), glycolipids (GL) and three unidentified lipids (L). Based on the differential physiological properties, biochemical characteristics and genotypic data, strain DBTR6^T represents a novel species of the genus Metabacillus, for which the name Metabacillus rhizolycopersici sp. nov. is proposed. The type strain is DBTR6^T (= ACCC 61900 ^T = JCM 35080 ^T).

Metabacillus kandeliae sp. nov., isolated from the rhizosphere soil of a decayed mangrove plant Kandelia candel

In this study, we isolated a novel Gram-stain-positive, aerobic, motile, rod-shaped bacterium, named GX 13764T, from the rhizosphere soil of a decayed mangrove plant Kandelia candel collected from Beihai, Guangxi, PR China, and characterized using a polyphasic taxonomic approach. The strain exhibited yellow-orange, round, convex, shiny, smooth, opaque and 2–3 mm diameter colonies on marine agar 2216 media after 3 days of incubation at 30 °C and was capable of growth at 4–45 °C (optimum, 30 °C), pH 5.0–9.0 (optimum, pH 7.0) and 0–4 % NaCl (w/v; optimum, 2 %). The strain was positive for catalase and negative for the oxidase. The main cellular fatty acid was anteiso-C15:0, iso-C15:0, iso-C16:0 and iso-C14:0. The cell-wall peptidoglycan comprised meso-diaminopimelic acid and the main menaquinone was MK-7. The polar lipids included one diphosphatidylglycerol, one phosphatidylglycerol, two glycolipids, two unidentified phospholipids and three unidentified lipids. Based on 16S rRNA gene analysis, GX 13764T presented the highest sequence similarity to Metabacillus mangrovi KCTC 33872T (97.04 %). The DNA G+C content of the type strain was 44.2 mol%. The average nucleotide identity values between GX 13764T and M. mangrovi KCTC 33872T, Metabacillus idriensis DSM 19097T and Metabacillus indicus LMG 22858T were 69.39, 68.87 and 68.95 %, respectively, with digital DNA–DNA hybridization values of 19.9, 19.5 and 19.5 %, respectively. Based on the polyphasic data, strain GX 13764T should be nominated as a novel species of the genus Metabacillus , for which the name Metabacillus kandeliae sp. nov. is proposed. The type strain is GX 13764T (=MCCC 1K06654T=KCTC 43366T).

Genomic and Physiological Characterization of Metabacillus flavus sp. nov., a Novel Carotenoid-Producing Bacilli Isolated from Korean Marine Mud

The newly isolated strain KIGAM252^T was found to be facultatively anaerobic, Gram-stain-positive, spore-forming, and rod-shaped. They grew at 10–45 °C, pH 6.0–10.0, and were able to tolerate up to 6% NaCl in the growth medium. Phylogenetic analysis indicated that the KIGAM252^T strain was related to the genus Metabacillus. The cell membrane fatty acid composition of strain KIGAM252^T included C_15:0 anteiso and C_15:0 iso (25.6%) as the major fatty acids, and menaquinone 7 was the predominant isoprenoid quinone. The major polar lipids were diphosphatidylglycerol and phosphatidylglycerol. The size of the whole genome was 4.30 Mbp, and the G + C content of the DNA was 43.8%. Average nucleotide and amino acid identity and in silico DNA-DNA hybridization values were below the species delineation threshold. Pan-genomic analysis revealed that 15.8% of all genes present in strain KIGAM252^T was unique to the strain. The analysis of the secondary biosynthetic pathway predicted the carotenoid synthetic gene cluster in the strain KIGAM252^T. Based on these current polyphasic taxonomic data, strain KIGAM252^T represents a novel species of the genus Metabacillus that produces carotenoids, for which we propose the name Metabacillus flavus sp. nov. The type of strain was KIGAM252^T (=KCTC 43261^T = JCM 34406^T).

Metabacillus bambusae sp. nov., isolated from bamboo grove soil

A bacterial strain designated BG109T was isolated from bamboo grove soil, and subjected to polyphasic taxonomic characterization. BG109T is an aerobic, non-motile, Gram-stain-positive and endospore-forming bacterium. BG109T showed growth at 10–40 °C (optimum, 37 °C), at pH 4–10 (optimum, 8), and in the presence of 0–7 % NaCl concentration (optimum, 0–1 %). The predominant menaquinone of BG109T was MK-7, and the cell wall peptidoglycan contained major amounts of meso–diaminopimelic acid as the diagnostic diamino acid. The diagnostic polar lipids were diphosphatidylglycerol and phosphatidylglycerol, and unidentified phospholipids and glycolipids were also present. The major fatty acids were anteiso-C15 : 0, iso-C15 : 0, iso-C14 : 0, iso-C16 : 0 and C16 : 0. The chemotaxonomic properties of BG109T were generally consistent with those of members of the genus Metabacillus . BG109T shared highest 16S rRNA gene sequence similarities with ‘Metabacillus elymi’ KUDC1714 (99.26 %), Metabacillus sediminilitoris DSL-17T (98.17 %), Metabacillus litoralis SW-211T (98.16 %) and Metabacillus crassostreae JSM 100118T (97.13 %), all of which were well below the suggested cutoff level for species distinction. The genome level relatedness also confirmed the separation of BG109T from other species of the genus Metabacillus . Thus, it is evident that BG109T merits recognition as representing a novel species of the genus Metabacillus , for which the name Metabacillus bambusae sp. nov. is proposed. The type strain is BG109T (=KCTC 43190T=JCM 34515T).

Metabacillus elymi sp. nov., isolated from the Rhizosphere of Elymus tsukushiensis, a plant native to the Dokdo Islands, Republic of Korea

Dokdo islands in Republic of Korea, is not suited to survive plant because strong wind, low organic content and high salinity. Nevertheless, 64 taxa of plants have a symbiotic relationship with microbe. The Metabacillus elymi KUDC1714^T was isolated from the rhizosphere of Elymus tsukushiensis collected from Dokdo Islands. This bacterial strain was Gram-stain positive, non-motile, non-spore forming, aerobic and rod-shape bacteria with 0.4-0.5 × 2.5-3.0 μm in size. Colonies were smooth, yellowish-white circular and 2.0-3.0 mm in diameter. KUDC1714^T was capable of growing at 10-45 °C (optimum, 30 °C), pH 7-11 (optimum, pH 8) and 0-8.0% (w/v) NaCl (optimum, 1.0-2.0%). Flagella were not observed by transmission electron microscopy. Phylogenetic analyses, based on 16S rRNA gene sequences, showed that KUDC1714^T belonged to the genus Metabacillus formed a phyletic lineage within the genus Metabacillus of the family Bacillaceae. The strain KUDC1714^T was most closely related to Metabacillus sediminilitoris DSL-17 ^T (98.2%), Metabacillus litoralis SW-211 ^T (98.2%) and Metabacillus halosaccharovorans E33^T (97.7%) based on 16S rRNA gene sequence. In silico DNA-DNA hybridization using genome-to-genome distance calculator were analysed at 25.8% and 23.5% in strain KUDC1714^T and Metabacillus sediminilitoris DSL-17 ^T, and strain KUDC1714^T and Metabacillus litoralis SW-211 ^T, respectively. Strain KUDC1714^T and its closet type strain were all below cut-off point of the average nucleotide identity and average amino acid identity values. The genome contains 5197 CDSs, 3 rRNAs, 118 tRNAs, 5 ncRNAs. The genomic DNA G + C content was 34.8 mol%. Its polar lipids were diphosphatidylglycerol, phosphatidylglycerol and its major fatty acids were anteiso-C_15:0 and iso-C_15:0. The strain KUDC1714^T contained menaquinone-7 as major isoprenoid quinone. Based on its genetic data, physiological and biochemical characteristics, strain KUDC1714^T should be considered a novel species of the genus Metabacillus, for which we propose the name Metabacillus elymi sp. nov. the type strain is KUDC1714^T (= KCTC 33222 ^T, = DSM 27608 ^T).