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

Abstract

A Gram-stain-positive, rod-shaped, non-spore-forming and non-motile bacterium, designated WY-20^T, 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^T belongs to the genus Nocardioides and showed the highest sequence similarity (98.1%) to N. phosphati WYH11-7^T, followed by N. cavernaquae K1W22B-1^T (97.8%), N. marmoriterrae JOS5-1^T (97.2%) and N. jensenii NBRC 14755^T (97.1%). The average nucleotide identity and digital DNA–DNA hybridization values between strains WY-20^T and N. phosphati WYH11-7^T were 83.5% and 26.2%, respectively. The predominant fatty acids (≥ 10% of the total fatty acids) were C_18:1ω9c, C_17:0, C_16:0, summed feature 8 (C_18:1ω7c and/or C_18: 1ω6c) and C_17:1ω9c. 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^T represents a novel species in the genus Nocardioides, for which the name Nocardioides jiangxiensis sp. nov. is proposed. The type strain is WY-20^T (= GDMCC 4.317^T = KACC 23379^T).