Arvimicrobium flavum gen. nov., sp. nov., A Novel Genus in the Family Phyllobacteriaceae Isolated From Forest Soil.

During the study of microbial diversity of forest soil in the Republic of Korea, a yellow pigment-producing, Gram-stain-negative, rod-shaped, motile bacterium was isolated and designated as strain 1W2. This strain grew at temperature of 10-37 °C, at pH of 5.0-9.0, and at NaCl concentration of 0-3.0% (w/v). The 16S rRNA gene sequencing and genome sequencing revealed that strain 1W2 is a member of the family Phyllobacteriaceae but exhibits low similarity with known genera, suggesting that this strain is a new genus within the family. This strain showed the closest similarity to the genera Mesorhizobium (96.6-96.9%), Aminobacter (96.4 -96.6%), Aquamicrobium (96.5-96.7%), and Pseudaminobacter (96.6-96.7%). The nearest relative of 1W2 was Mesorhizobium shangrilense CCBAU 65327 with the 16S rRNA gene sequence similarity of 96.9%. The genome size was 5,545,526 bp with DNA G + C content of 64.7%. The values of overall genomic relatedness indices between strain 1W2 and the reference members were 20.4-21.3% for digital DNA-DNA hybridization, 74.0-76.6% for average nucleotide identity, and 68.1-61.2% for amino acids identity. Chemotaxonomic profiling revealed that Q-10 was the sole ubiquinone; summed feature 8 (Cω7c and/or Cω6c), iso-C, and C cyclo ω8c were the predominant fatty acids; and diphosphatidylglycerol, phosphatidylglycerol, phosphatidylmethylethanolamine, phosphatidylcholine, and phosphatidylethanolamine were the major polar lipids. Based on these data, strain 1W2 represents a novel species of a new genus in the family Phyllobacteriaceae. Accordingly, we proposed the name Arvimicrobium flavum gen. nov., sp. nov., with the type strain 1W2 (= KCTC 92441 = NBRC 116019).