Identifieation Of Marine Bacillus Subtilis Antagonist To Magnaporthe Grisea And The Tentative Exploration Of Its Antimicrobial Substances

Rice Blast is the most serious diseases of the main diseases of rice, all over the world.Traditional methods of controlling rice blast with hemical control and Breeding diseaseresistant varieties. However, due to the abuse of chemical pesticides causing seriousenvironmental pollution and can accumulate in plants and animals, such as harm to humansand animals. The uncity of resistant varieties that it can not create a good control of rice blast.At present, with the development and application of biological pesticide and limited landresources, more and more people choose from screening to prevent plant diseases in Marinemicrobial resources, to develop new type of biological pesticide. This study collected samplesfrom liaoning dalian bay area,221bacterial strains were screened by oxford cup method andplate confrontation. Among them,179bacteria,24fungi, actinomycetes18. And rice blastfungus to indicate strains for screening and rescreening by flat confrontation method to obtainfive strains inhibited, which strain of rice blast suppression good effect by morphological,physiological and biochemical characterization and identification of16s rDNA Bacillussubtilis is a marine named DL-006.Through the filter of DL-006for single-factor such as Carbon Source, nitrogen source,inorganic salt and culture time,culture temperature,the initial pH,rotation speeds andinoculation of such conditions for fermentation optimization. Results is that the best carbonsource is sucrose, the best nitrogen source is tryptone, inorganic salt best choice is to NaCl.The experiment of single factor optimization of fermentation, the fermentation time is72h,fermentation temperature30℃, initial pH is7, inoculation amount8%, the rotation speed is180rpm.Finally, according to the Phytophthora nicotianae、Exerohilum turcicum、Fusariumgraminearum Schw. Xanthomonas oryzae、Candidia albicans test results show that DL-006can broad-spectrum resistance to pathogens. Application of optical microscope and electronmicroscope microscopic observation was carried out on the DL-006inhibition of rice blastfungus. Results showed no inhibition of rice blast fungus hypha growth even thickness, notoutstanding, outstanding is restrained hypha after enlargement, severe deformity.Using ammonium sulfate precipitation and isoelectric point precipitation,getsantibacterial activity of protein substances, and the strain DL-006could produce extracellular protein active substances with antibacterial effect, According to this conclusion, DL-006fermentation supernatant of vacuum freeze drying of Tricine SDS-page and massspectrometry analysis, results can be seen in the fermentation broth containing a variety ofprotease substances.