Diversity of rhizospheric bacteria and its inhibition activity from Sonneratia apetala in Maowei Sea

ObjectiveDiversity and inhibition activity of rhizospheric bacteria which came from Sonneratia apetala in Maowei Sea were studied to find out more potential new species and high-efficiency active materials,and provided re-ference for the further research on secondary metabolites of the rhizospheric bacteria of mangrove plant and the further de-velopment of new and efficient biological pesticides.MethodThe rhizosphere soil of S. apetala were collected from Maowei Sea mangrove reserve in Qinzhou,Guangxi. Six different media were employed to isolate the cultured bacteria. The species diversity was revealed through phylogenetic analysis of the 16S rRNA gene sequence,and Oxford cup method was used to investigate the inhibitory activity of the rhizosphere bacteria against Sporisorium scitamineum.ResultThe 97 strains of culturable bacteria were isolated from the rhizosphere of S. apetala.After comparing the 16S rRNA sequence alignments,57 different strains of bacteria were obtained,which could be classified into 21 genera,15 families,9 or-ders,5 classes and 4 phyla. There was also a potential new species of Cellvibrio sp. The 29 strains could inhibit the activi-ty of S. scitamineum. That there were 12,14 and 14 strains of bacteria exhibited inhibitory activity against mycelium growth,proliferation of"+"spores,and proliferation of"-"spores of S. scitamineum respectively. The diameter of inhibi-tion zone was between 7.54 and 21.81,and 9 strains of which could inhibit the morphology of 2 to 3 species of S. scitamin-eum .ConclusionThe rhizospheric bacteria of S. apetala which come from Maowei Sea mangrove reserve in Qinzhou, Guangxi have high species diversity,contain potential new species resources,and are rich in antibacterial activity strains.