北部湾徐闻海域红树内生细菌物种多样性及其杀线虫活性研究.

In order to find endophytie bacteria resources and search for new microbial insecticides from mangrove plants, the bacteria were isolated from sixteen samples of seven mangrove plants which collected from Beibu Gulf coast at Xuwen with designed ten kinds of isolation media. The 16S rRNA molecular biology method, dilution coating method and Caenorhabditis elegans screening model were used to explore the diversity and nematicidal activity of endophytic bacteria isolated from mangrove plants. The results were as follows:(1)A total of 33 endophytic bacteria were isolated by 16 organs and tissues which could be classified into 19 families and 23 genera and the dominant genus were Bacillus, and ten potential new species or genera were obtained.(2)Through the nematicidal activity test, two kinds of bacteria with nematicidal activity were obtained. Two endophytic bacteria IMDGX 4725 and IMDGX 4744 had the extremely significant nematicidal activities and the lethal concentrations of 50% were 61.58 and 100.89 mg·mL-1, respectively. The research confirm that mangrove plants collected from Xuwen are rich in endophytic bacteria. At the same time, parts of the bacteria have strong nematicidal activity, which could be a potential source for the discovery of the new microbial insecticides. [ABSTRACT FROM AUTHOR]