The Isolation,Identification,Fermentation Condition And The Fermented Liquid Antibacterial Material Research Of The Biological Control Agents Endophyte MG-3 In Mango

There is a kind of microorganism which can restrain Lasiodiplodia in mango.After being isolated and identified,it belongs to Bacillus amyloliquefaciens ascertainly..In this paper,firstly,we used the methods of molecular biology to identify the microorgansm.Then researched its biological characteristics.At last,we discussed the isolating and purifying methods,physio-biochemical characteristics and its Preservation mechanism.The main results were summarized as follows:(1)Mango endophytes MG-3 thallus presented the shape of rhabditiform,its ha d rough opaque surface,it had irregular edge,the result of bacterium of color react ion was masculine,its spore presented the shape of ellipse.The 16s DNA series of mango endophytes MG-3 had the homology of 100%with bacillus amyloliquefacie ns.From the angle of the DNA amplification to explain,belonged to bacillus amyl oliquefaciens.Moreover,And results of Contact enzyme reaction,Anaerobic growth tests,V-P measure,nitrate reduction test were all masculine.While the result of the oxidase test was negative.The result of the starch hydrolysis test,gelatin liquefy action test,2%-7%salt resistance test,pH6.8 and pH5.7 nutrient broth test,30℃,40℃ and 50℃ growth temperature test,dairy grain hydrolysis test were-all masculin e.The result of the sugar alcohol fermentation tests,phenylalanine to take off the ammonia enzyme test,10%salt resistance test,nagler’s reaction,indole test,tyrosin e hydrolysis test,60 ℃ growth temperature test,propionic acid salt test were negative.By the result of berger bacteria appraisal manual and common system identificatio n manual,mango endophytes MG-3 was coinside with bacillus amyloliquefaciens.(2)With the single factor experiment,we have researched the conditions which could influence growth situation of bacillus amyloliquefaciens MG-3,then by the re sult of the experiment,we designed the orthogonal test to confirm the best foster c onditions of it.The resules showed that the best foster conditions of bacillus amylo liquefaciens MG-3 were:used the concentration of 3%corn starch as carbon source,used the concentration of 3‰ ammonium acetate as nitrogen source,the culture te mperature was 32 ℃,used 150mL taper to put 100mL culture medium as its throug hput,inoculum concentration was 3%,the initiative pH was 7.5.In this best condi tion,the antibacterial rate of the secondary metabolite was 81.63%.(3)Firstly,ammonium sulfate precipitation method was used to obtain the activ e material which bacillus amyloliquefaciens MG-3 produced.Then macroporous abs orption resin was used to isolate small molecules with the active material.And afte r that,activated carbon was used to wipe out pigment kind material.At last,sepha dex was used to purify the active material to get the higher purified material.By t hen,impurities kind materials were almost wiped out,and the antibacterial rate of t he active material was 65.47%.(4)Use the purified material as the research object,physio-biochemical character istics were researched.The experimental results show that,active material which pr oduced by bacillus amyloliquefaciens MG-3 was in the conditions of hested by the temperature of 100℃ in three to twenty minutes,the pH scope was two to twelve and the Lamp uv irradiation time was ten to sixty minutes,the bacteriostatic activit y of the active material was not influenced.Incubated in proteinase and trypsin by five hours,the bacteriostatic activity of the active material was slightly decreased.T he bacteriostatic mechanism of the active material which produced by Bacillus amyl oliquefaciens MG-3 was it leaded pathogenic bacteria growth deformitied.Pathogeni c bacteria couldn’t grow or reproduce normally.