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).

Current Topics in Lactic Acid Bacteria and Probiotics, 한국유산균프로바이오틱스학회 학술지

The novel bacterial strain MBLB1776^T was isolated from marine mud in Uljin, the Republic of Korea. Cells were Gram-positive, spore-forming, non-motile, and non-flagellated rods. Growth was observed at a temperature range of 10–45 °C, pH range of 6.0–8.0, and NaCl concentrations of 0–4% (w/v). Phylogenetic analysis of the 16S rRNA gene sequence revealed that MBLB1776^T belonged to the genus Paenibacillus and was closely related to Paenibacillus cavernae C4-5^T (94.83% similarity). Anteiso-C_15:0, iso-C_16:0, C_16:0, and iso-C_15:0 were the predominant fatty acids. Menaquinone 7 was identified as the major isoprenoid quinone. The major polar lipids included diphosphatidylglycerol, phosphatidylglycerol, and phosphatidylethanolamine. Its whole genome was 6.3 Mb in size, with a G+C content of 55.8 mol%. Average nucleotide identity and in silico DNA–DNA hybridization values were below the species delineation threshold. Gene function analysis revealed the presence of a complete C₃₀ carotenoid biosynthetic pathway. Intriguingly, MBLB1776^T harbored carotenoid pigments, imparting an orange color to whole cells. Based on this comprehensive polyphasic taxonomy, the MBLB1776^T strain represents a novel species within the genus Paenibacillus, for which the name Paenibacillus aurantius sp. nov is proposed. The type strain was MBLB1776^T (=KCTC 43279^T = JCM 34220^T). This is the first report of a carotenoid-producing Paenibacillus sp.