Genome insight and description of antibiotic producing Massilia antibiotica sp. nov., isolated from oil-contaminated soil

초록

An ivory-coloured, motile, Gram-stain-negative bacterium, designated TW-1(T) was isolated from oil-contaminated experimental soil in Kyonggi University. The phylogenetic analysis based on 16S rRNA gene sequence revealed, strain TW-1(T) formed a lineage within the family Oxalobacteraceae and clustered as members of the genus Massilia. The closest members were M. pinisoli T33(T) (98.8% sequence similarity), M. putida 6NM-7(T) (98.6%), M. arvi THG-RS2O(T) (98.5%), M. phosphatilytica 12-OD1(T) (98.3%) and M. niastensis 5516S-1(T) (98.2%). The sole respiratory quinone is ubiquinone-8. The major cellular fatty acids are hexadeconic acid, cis-9, methylenehexadeconic acid, summed feature 3 and summed feature 8. The major polar lipids are phosphatidylethanolamine, diphosphatidylglycerol and phosphatidylglycerol. The DNA G+C content of the type strain is 66.3%. The average nucleotide identity (ANI) and in silico DNA-DNA hybridization (dDDH) relatedness values between strain TW-1(T) and closest members were below the threshold value for species demarcation. The genome size is 7,051,197 bp along with 46 contigs and 5,977 protein-coding genes. The genome showed 5 putative biosynthetic gene clusters (BGCs) that are responsible for different secondary metabolites. Cluster 2 showed thiopeptide BGC with no known cluster blast, indicating TW-1(T) might produce novel antimicrobial agent. The antimicrobial assessment also showed that strain TW-1(T) possessed inhibitory activity against Gram-negative pathogens (Escherichia coli and Pseudomonas aeruginosa). This is the first report of the species in the genus Massilia which produces antimicrobial compounds. Based on the polyphasic study, strain TW-1(T) represents novel species in the genus Massilia, for which the name Massilia antibiotica sp. nov. is proposed. The type strain is TW-1(T) (=KACC 21627(T)=NBRC 114363(T)).