Characterization Of Bacillus Subtilis J-5 Andanalysis For Its Ability To Inhibit Botrytis Cinerea

Gray mold is the most harmful and difficult control disease which caused by Botrytis cinerea and infected many kinds of fruits and vegetables in China.So it is important to find safe and effective biological control strains to control the disease.In this study,six bacteria with inhibitory effect on Botrytis cinerea were isolated.The J-5 strain had the highest inhibition rate to the mycelial growth of Botrytis cinerea.The strain J-5 were identified as Botrytis cinerea by the analysis of morphological and physiological and biochemical properties and 16 S rDNA coding sequence.the strain has CGMCC No.11750,the GenBank number KY357320.The optimum culture conditions and the optimal conditions for filtrate were optimized.the results revealed that the optimal culture temperature,pH,culture time and the volume of liquid was 37?,7,24 h,and 50 mL respectively.In this study,the inhibition activity of J-5 filtrate was determined by mesure the inhibition mycelial growth.It was found that the filtrate had a significant inhibitory effect on tomato gray mold in vitro and in vito.Also the volatile substances of the strain J-5 had a significant inhibitory effect on tomato gray mold.the antifungal activity of the filtrate was stable across a broad range of the temperature(37?-121?),alkaline(pH 8-11)protease(protease K,pepsin,trypsin).But it is unstable to acid(pH<4)and UV.The active ingredients were obtained by hydrochloric acid precipitation method,and then the effective substances were separated by AKTA pure.Three ingredients could inhibit the gray mold effectively.The related genes of synthetic iturin,fengycin,surfactin strain J-5 were detected by the antibiotic synthesis gene PCR.Through whole genome sequencing and comparative genomics analysis of the J-5,we found that the genome of J-5 is 4,117,900 base pairs which comprises 4312 protein-coding genes.The average GC ratio is 46.11%.It contains 87 tRNA,27 rRNA,9 sRNA.The sequencing results had been submitted to the GenBank database and recived the accession number: CP018295.Through comparative genomics analysis,we found that J-5 contains 1105 specific genes compared with other four strains in NCBI.In the COG database,there are 110 genes involved in the biosynthesis of secondary metabolites,including genes that synthesize iturin,fengycin,surfactin,and some unknown genes worthy of our study.