Nocardioides jiangxiensis sp. nov., a novel actinobacterium isolated from lakeside soil, exhibiting the biosynthesis potential of mycofactocin.

A Gram-stain-positive, rod-shaped, non-spore-forming and non-motile bacterium, designated WY-20, was isolated from a lakeside soil sample collected in Jiangxi Province, PR China. Growth was observed at 20-42 °C (optimum 30 °C), pH 5.0-8.0 (optimum pH 7.0) and salinity of 0-3.0% (w/v; optimum 0.5%). Phylogenetic analysis based on the 16S rRNA gene sequences indicated that strain WY-20 belongs to the genus Nocardioides and showed the highest sequence similarity (98.1%) to N. phosphati WYH11-7, followed by N. cavernaquae K1W22B-1 (97.8%), N. marmoriterrae JOS5-1 (97.2%) and N. jensenii NBRC 14755 (97.1%). The average nucleotide identity and digital DNA-DNA hybridization values between strains WY-20 and N. phosphati WYH11-7 were 83.5% and 26.2%, respectively. The predominant fatty acids (≥ 10% of the total fatty acids) were Cω9c, C, C, summed feature 8 (Cω7c and/or Cω6c) and Cω9c. The major menaquinone was MK-8 (H4). The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol and two unidentified phospholipids. In addition, meso-diaminopimelic acid was the diagnostic diamino acid in the cell-wall peptidoglycan. Based on phenotypic, genotypic and phylogenetic pieces of evidence, strain WY-20 represents a novel species in the genus Nocardioides, for which the name Nocardioides jiangxiensis sp. nov. is proposed. The type strain is WY-20 (= GDMCC 4.317 = KACC 23379).