Isolation, Identification And Optimizing Fermentation Conditions Of Actinomycetes Strain ND045

At present, the plant disease prevention and treatment based mainly on chemical control, but chemical pesticides easy on the environment caused by pollution and ecological, sustainable agriculture is the biological control of plant diseases in the preferred means of prevention and treatment. In order to explore Pepper Anthracnose biocontrol agents to control disease spread in pepper production.Six antagonistic actinomycetes strains were isolated from the cultivated soil samples of Yulongxueshan and Liuyang River Scenic Belt, among which ND045 strain exhibited the highest antagonistic activity against Collectotrichum acutata after the growth confrontation test and culture filtrate inhibition test.The results indicated that ND045 showed the inhibition rate of 71.6%.Use the 16S rRNA gene universal primer 18,19 of prokaryotes for PCR amplification for sequencing, the results of the NCBI for BLAST, the results of ND045 sequence with a number of species of Streptomyces sequences are as high as 99%, combined with morphological characteristics, Biochemical and physiological characteristics of the culture characteristics of their initial judgments were Streptomyces hygroscopicus.Further antimicrobial spectrum of ND045 was tested against Magnaporlhe grisea, Phytophthora capsici, Fusarium omysporum and Sclerotium rolfsii.The result indicated that ND045 showed the inhibition rate between 40.58% and 72%.The optional fermentation conditions for antibacterial substance production of ND045 were rice flour 15.0 g, soybean flour 10g, MgSO4 0.5g, FeSO4·7H2O 0.01g, NaCl 1.5g, water 1000mL,fermentation temperature 30℃and pH at 8 through one-variable method and Uniform design. After optimization, the inhibition rate of mycelial growth was up to 82.61%, increased for 11.01% more than before.The results provide scientific evidence to Pepper Anthracnose biocontrol.