Abstract:[Background] The emergence and dissemination of new mobile antibiotic resistance genes such as ndm and mcr, poses a great threat to the treatment of infections associated with multi-drug resistant Gram-negative bacterial pathogens. [Objective] To screen new antibiotics, bacterial candidates were isolated and characterized against Gram-negative bacteria. [Methods] First, bacterial strains were isolated from soils using tryptic soy agar (TSA), and identified by 16S rRNA gene sequencing. Then, bioinformatics analysis was performed based on the whole genome. Meanwhile, the secondary metabolites of the candidate strains were predicted by antiSMASH and antibacterial activity was confirmed by the double layer agar plate assay. Finally, the crude was extracted in methanol and identified using HPLC-MS/MS. [Results] Paenibacillus pabuli CAU136 was isolated from the soil in Beijing, China. The whole genome sequence and antiSMASH analysis showed the great potential of P. pabuli CAU136 to produce secondary metabolites against bacteria. P. pabuli CAU136 showed antibacterial activity against different Gram-negative bacterial strains using the double layer agar plate method. Colistin in the crude extracts of P. pabuli CAU136 was demonstrated based on HPLC-MS/MS analysis. [Conclusion] P. pabuli CAU136 may produce colistin against diverse Gram-negative bacterial strains.
