The Diversity And Antimicrobial Activity Of Endophytic Bacteria Isolated From Sophora Alopecuroides

Because of antimicrobial activity and plant growth-promoting effect, endophytic bacteria become an important source of biocontrol agents and new drug for people, plants and animal disease treatment. This paper isolated and purified endophytic bacteria lived in different tissues of Sophora alopecuroides at Xinjiang province, screened antagonistic endophytic bacteria against the cotton pathogens such as Verticillium dahliae and Fusarium oxysporum, studied the diversity and phylogenetic position of the antagonistic strains, researched antagonistic pot experiment and mechanism of bial-control disease, screened antagonistic strain against the MRSA and its active components. The main conclusions are following.1. 202 endophytic bactria strains were isolated from different organization of Sophora alopecuroides at Xinjiang province. The species of endophytic bacteria in difference organization of Sophora alopecuroides were obviously difference, which distributed rule was decreasing progressively in nodule, leaf, seed, root, stem and flower.2. All of 202 endophytic bacteria had antagonist activity against to Verticillium alboatrum and Fusarium oxysporum and inhibition rate of 125 strains against to Verticillium alboatrum and Fusarium oxysporum was more than 50%. Extracellular secretion of 48 antagonistic endophytic bacteria had the inhibitory action against to Verticillium alboatrum and Fusarium oxysporum.3. Phynotype of 48 antagonistic endophytic bacteria was divided into 7 cluster apparently and 12 independence strains at 0.23 of Waston distance. The ERIC-PCR fingerprint analysis of 48 antagonistic endophytic bacteria was indicated into 6 ERIC groups and two independence strain at 0.31 of Watson distance. The result of two kind of analysis method was consistent. Ten type strains belong to Bacillus atrophaeus, Bacillus subtilis, Bacillus cereus, Bacillus megaterium, Bacillus pumilus, Serratia marcescens.4 Five antagonistic endophytic bacteria had the control effects of against to Verticillium alboatrum and Fusarium oxysporum in pot tests. The control effects of KDRE51 and KDEB30 against to Verticillium alboatrum and KDRE51 and KDRE01 against to Fusarium oxysporum was rather better than ningnanmycin.5 KDRE51 had antagonistic action against to Verticillium alboatrum and Fusarium oxysporum by producing the active chemical substance, iron siderophore and the induce system resistant. Producing the active chemical substance was main oppresses mechanism.6 KDRE51 has strongly antagonistic activity against to MRSA. The inhibitary circle diameter of compound ZSC-6 proceded by KDRE51 achieved 22 mm to the MRSA. Compound ZSC-6 was determined as 1-(5-chlorine-5-methoxyn-pentane base)the tetrahydropyrrole-2-alkone by comparison of the GC-MS total ionic chromatographic, infrared absorption spectrum, 1H- NMR and 13C-NMR spectral data.