Whole genome analysis of sp. RerS4, a rhizosphere microbe producing a new lipopeptide.

, a valuable medicinal plant, is threatened by ring rot, a condition that greatly affects its yield and quality. Interactions between plant and the rhizosphere soil microbiome in the context of pathogen invasion are generally more specific, with recruitment of specialized microbes potentially antagonistic to a certain pathogen. Isolation of microorganisms from rhizosphere soil of healthy and ring rot-infected was carried out to screen antifungal microbes. A strain designated RerS4 isolated from ring rot-infected rhizosphere soil with strong antifungal activities was selected for further study. RerS4 was taxonomically characterized as the genus according to its morphology and 16S rRNA sequences that were most closely related to NRRL B-5430 (99.72%) and NBRC 13072 (99.72%). A new lipopeptide isolated from RerS4 showed restrained proliferation, but was devoid of significant antibacterial and antioxidant activity with minimum inhibitory concentration (MIC) values of 20.3 ± 2.5 and 70.8 ± 3.7 μg/mL and half-maximal inhibitory concentration (IC) values of 23.3 ± 0.8 and 58.8 ± 2.9 μg/mL, respectively. In addition, we report the complete genome sequence of sp. RerS4, which consists of a 7,301,482 bp linear chromosome and a 242,139 bp plasmid. Genome analysis revealed that sp. RerS4 contained 25 biosynthetic gene clusters (BGCs) for secondary metabolites, among which 68% had low similarities with known BGCs, leading us to believe that sp. RerS4 could produce valuable bioactive compounds.