Isolation And Identification Pepper Bacterium JMY-3 And The Research Of Antibiotic Activity

In this study,endophytic bacteria was isolated and screened from pepper,obtained a strain JMY-3 which had antibacterial activity against many pathogenic fungi.This study focused on the taxonomical,the fermentation conditions,inhibitory effect,growth-promoting and pot control effect,the results were as follows:1.Isolated 35 strains of endophytic bacteria from the different tissure of pepper with tissue isolation method,than used plate confrontation method to determine its bacteriostatic activity,the antagonistic effects showed that 3 of them expressed strong antibiotic activity on Alternaria alternata.Through the study of the strain and its fermentation broth,finded that the JMY-3 performed high antagonist activity to Alternaria solani and Botrytis cinerea.2.1n the experiment,the antagonistic strain JMY-3 was identified by morphology?physiological and biochemical characteristics as well as the 16SrDNA.In the end,the strain was identified as Bacillus amyloliquefaciens.3.In the experiment,single factor tested and orthogonal experiments were adopted to optimize the fermentation conditions of the JMY-3.We analyzed the growth of bacteria and the activity of metabolites by spectrophotometer,and obtained the optimum fermentation conditions:basic medium is NYBD medium,the best carbon source was maltose,the best nitrogen source was beef extract and tryptone,ph was 9,liquid volume in flask 150 mL,bacterial load 5%,fermentation time 24 h,and rotational speed 130 r·min-1.4.Extraction of fermentation broth with 5 kinds of organic solvents,we found that all of them had no antimicrobial activity.But it showed bacteriostatic activity by way of fractional salting out,and combination with the characteristics that under the condition of high temperature,the fermented liquid was easy to lose activity,speculating its antimicrobial components was protein.5.Salt fractionation with ammonium sulfate to fermentation broth and detect its activity,it showed that the best salted saturation was 20~40%.Through study of stabilization of the crude protein by different temperature?different pH and ultraviolet light,we can saw that the protein was found to be thermostable under 100?,the antifungal activity was best under 9.0 the rough proteins were unsensitive to ultraviolet light.6.In this article,growth-promoting ability of JMY-3 were researched,the growth-promoting effect showed that JMY-3 fermentation broth had significant promoting effect to seed germination rate,In the aspect of buds length,seeds that treated by the dilution of fermentation broth at 100 times were longer than control group and other treatment groups,the growth rate reached 24%.JMY-3 fermentation broth had no significant promoting effect to seeding growth,the test showed:the strains had good development and potential applications.7.Potted control effect ressult showed that:when spraied fermented and vaccination of plant pathogenic bacteria at firstly,control effect respectively were 55.12%?44.61%,control effect was in general,when both these two liquid spraied,the control effect was best and it was 70.13%.