Myxobacteria From Vietnam: Isolation, Phylogenetic Analysis and Bioprospection

AbstractMyxobacteria have been considered microbial factories for producing secondary metabolites that have a variety of potential biological actions for discovering and isolating new biological molecules. Forty-three myxobacterial strains were isolated and identified from 20 soil samples collected in Vietnam. The information on morphological characteristics and phylogenetic analysis inferred from 16S ribosomal gene showed that the newly isolated myxobacterial strains were classified into seven genera ofAngiococcus,Archangium,Corallococcus,Cystobacter,Melittangium, andMyxococcus. Antioxidant activity was measured with the DPPH and ABTS assays; the minimum inhibitory concentration values were determined by the microdilution method. The extract from CT21 strain had the highest total antioxidant activity (IC50= 52.34 ± 1.47 and 30.28 ± 0.74 μg/mL for the DPPH and ABTS, respectively). Interestingly, all strains isolated myxobacterial strains show inhibitory activity against at least one of the tested microorganisms. The most potent antimicrobial strain was GL41, which inhibited all tested microorganisms, and the MIC values were 1 μg/mL against MRSA, MSSA,S. faecalis,C. albicans, andA. niger. Almost all active strains were members of theMyxococcusgenus, among of which, GL41 strain was identified asMyxococcus stipitatus. Myxobacteria strains isolated from soil are a potent source of bioactive metabolite production.