Optimization Of Fermentation Technology Of Bacillus Spp. AMCC100150 And Its Control Effect In Root-Knot Nematodes Of Cucumber

Root-knot nematodes are very damaging soilborne pathogens that hurt root growth and development and subsequently block utilization of nutrients and water.Several chemical nematicides can effectively control root-knot nematode,but their use is strictly limited and even banned in the world for they cause serious pollution of environments and greatly damage to human health.Therefore,exploration of new and environment-friendly biocontrol alternatives is very urgently needed.The Bacillus sp.has gradually became a hot research in biocontrol applications and Bacillus belongs to the Bacillus sp.which has the ability to inhibit fungi and bacteria,thereby it has high research values and potentional for development,which was widely used in industries of preservation.This study starch Bacillus spp.from the solution of the root knot nematodes of cucumber and optimize the fermentation conditions were studied in two aspects,the results are as follows:(1)This paper reports firstly the nematicidal activity of Bacillus spp.on Meloidogyne spp.Juveniles,individual egg and eggs in masses hatching in vitro.The mortality ratio of the second-stage juveniles of Meloidogyne spp.was over 85% and the inhibition of individual egg and eggs in masses hatching was above 100% when they treated by 12 h fermentation broth.And that the fermented production of nematicides pH1.0-13.0,and wide range tempreture are still stability for its activity respectively.(2)The control effect of the fermentation supernatant of the Bacillus spp.to Meloidogyne spp.in greenhouse was studied.The results showed that the biological control efficiency of Bacillus spp.was 70%.So Bacillus amyloliqefaciens is a potential strain for biological control.(3)Optimization of fermentation technology of Bacillus spp..About 16 fermentation culture media,which are suitable for Bacillus,were compared on the basis of endospore yield.The medium which brings the highest spore quantities was chose as the basic medium for fermentation of Bacillus spp..Plackett-Burman(PB)was used to find the main factors to influence the quantities of spore among the components of basic medium.Fermentation medium for Bacillus were selected by PB design and Response Surface Analysis in shake-flask.Results showed that optimum fermentation medium component for Bacillus spp.was corn flour 2.88%,glucose 0.5%,bean flour 1.68%,CaCO3 0.7%,K2HPO4 0.03%,MgSO4·7H2O 0.02%,MnSO4·H2O 0.02%.The final optimized system allowed the spore quantities of Bacillus to 3.35×109CFU/mL in flask.To enhance by 27.86%.