| The results of isolation by the surface sterilized with 0.1% mercury bichloride showed that 2.83×103~1.35×104cfu/g(fw) endophytic bacteria were obtained from the plants of capsicum; 3.4x103~4.5xl04cfu/g(fw) from leaves, 0.75×10-3-1.3×103 cfu/g(fw) from roots, 0.1×103~3.25×103 cfu/g(fw) from stems and 0.3xl03~1.8xl03 cfu/g(fw) from fruits. A total of 108 endophytic bacteria isolates, 31, or 28.7%, had in vitro inhibitory activity to phytopathogens of fungi, such as Fusarium oxysporum f.sp.cubense, Fusarium oxysporum f.sp.cucumberinum, and Colletotrichum sp.,etc. The strongest inhibitory activities were produced by the BS-1 and BS-2 strains which isolated from the leaf and stem respectively. Based on the basic properties including cell shape, Gram's stain, sporulation, production of catalase and oxidase, all of the 31 antagonistic isolates were identified as Bacillus spp., BS-1 and BS-2 were further identified as B. subtilis by the Biolog analysis, and based on the colonized in the plants and signature sequences of 16S rRNA, the two strains may be belonging to the B.subtilis subsp. endophyticus.The mutanted by antagonism against the rifampicin, and inoculated by dipping seeds, daubing leaves, and watering roots, the two strains were proved to be able to colonize in the many kinds of plants, such as eggplant, cabbage, muskmelon, watermelon, loofah goard, besides that the BS-2 was able to colonize in more plants which were tomato, cucumber, cowpea, rice and wheat etc. The results also showed that the two strains were able to live and move in the plants of capsicum and the BS-2 in the cabbage plant for long time.The growth of capsicum and cabbage was significantly promoted by BS-2 and BS-1 strains with their cells suspension dipping seeds. Compare with the water control, the fresh weight of the 15d old capsicum seedling was increased 146.72% and 58.58% respectively tested in the pots; and 72.02% and 63.04% respectively tested in fields; and that of the 20d old cabbage was increased 91.20%~138.04% and 25.43%~55.43% respectively tested in fields. Inducing the change of plant hormone concentration may be one of the key mechanisms in promoting growth activities of the two strains.The anthracnoses of capsicum seedling and fruits, cabbage and banana, which were caused by Colletotrichum gloeosporioides, C. higgisianum and C. musae respectively, were found effective controlled by the BS-2 and BS-1 strains. The control effects of the BS-2 strain on the above anthracnoses were 81.49%~93.34%, 80.0%~100%> 45.12% and 71.54% respectively; and that of the BS-1 were66.13%~79.23%. 60.0%~100%?68.45% and 43.28% respectively. The results also showed that the secreting antibiotics which had strong inhibitory activity against the pathogens mycelial growth and conidia formation and germination, colonizing in the plants and promoting their growth, and inducing the plants defense responses were proposed to be the key mechanism in the disease control activity of the two strains.The BS-2 antifungal compound obtained through ammonium sulfate precipitation was primarily identified as a polypeptide (MW <=2884.39D) by SDS-PAGE and MALDI-TOF. This antifungal polypeptide of the nature of thermostable and UV-tolerant showed strong inhibitory activity against various plant pathogenic fungi and bacteria, such as Colletotrichum sp. and Ralstonia solanaceance, and had 69.79% control effect (9d after inoculating the pathogen) against the anthracnose on the capsicum postharvest fruits.Optimum fermentation conditions for BS-2 might culture for 48h at 28℃ with the medium made of soybean powder(pH6.7), and increase the oxygen supply as much as possible.
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