The Biological Characteristics And Fermentation Process Of Streptomyces Lavendulae Var. Streptinus Antagonistic Strain T0907-15

The antibacterial activity and related biological characteristics of Streptomyces lavendulae var.streptinus antagonistic strain T0907-15were studied by using methods of plat streaking, rubbing,plate confrontation, cylinder-plate and pot test. Its fermentation conditions were optimized byusing single factor method and orthogonal test, and pilot test was done in10L fermentor. Themain results were as follows:1. Growth characteristics of strain T0907-15: Its growth characteristics was tested by usingmethods of streaking, rubbing and cylinder-plate. The results showed that its colonies were in amature state after growing in Gause I medium for7d⁸d; strain T0907-15colony growth,morphology of substrate mycelium and aerial mycelium, size and number of mycelia wereinfluenced by lack of the different elements. It was more sensitive to high concentration potessiumdichromate(>400μg·mL^-1), and it can alse be tolerated low concentration potessium dichromate.2. Antibacterial activity of strain T0907-15: Its antibacterial activity toward plant pathogenswas tested by using methods of plate confrontation, cylinder-plate and pot test. The results showedthat it had wide bitory spectra on plate vivo antibacterial activity, it had certain inhibition effecttoward Botrytis cinerea Pers., Colletotrichum nicotianae Av.Sacca, Phytophthora infestans (Mont.)De Bary., Alternaria alternata (Fries)Keissler, Colletotrichum higginsianum Sacc.,Helminthosporium sigmoideum Cav., Sclerotium oryzae-sativae Saw., Fusarium oxysproumSchlecht, Fusarium solani var. coeruleum (Sacc.) Booth; its seed broth in different growth periodsshowed different antibacterial activity, its antibacterial activity was strongest when it hadfermented for3days, its antibacterial activity of seed broth was stronger than supernatant, andstrength of broth antibacterial activity after organic solvent extraction respectively: acetone>ethanol> methanol> n-hexane underlayer> ethyl acetate underlayer, its organic solventextraction which had antibacterial activity was got the whole wavelength scanning map byultraviolet spectrophotometer; its broth of different concentration treatment against Botrytiscinerea Pers showed certain protection and treatment effect, its protection effect was stronger thantreatment effect.3. Fermentation conditions optimization of strain T0907-15: its fermentation optimization wastested by using single factor method and orthogonal test. The results showed that its bestcarbon/nitrogen-ratio was10, its best shrimp shells powder concentration was15g·L^-1, its bestcarbon source was glucose, and its best seed medium was every1L medium containing15gshrimp shells powder and9.00g glucose; the results of fermentation medium optimization werethat corn flour8.75g· L^-1, peptone2.5g·L^-1, K₂HPO₄·3H₂O1.25g·L^-1, MgSO₄·7H₂O2.0g·L^-1,NaCl1.0g·L^-1, CaCO33.0g·L^-1; on the basis of fermentation medium optimization, the results of fermentation conditions optimization were that seed age was4d, fermentation temperature was30℃, inoculation volume was12.5%, initial pH was7.20, liquid volume in flask was150mL,shaking speed was200r·min^-1; according to optimization results of its fermentation conditions,antagonistic actinomycetes T0907-15did expand culture in10L fermentor, its fermentationconditions were that fermentation temperature30℃, inoculated quantity12.5%, initial rotationspeed150r·min^-1, initial dissolved oxygen100%, initial ventilation ratio6vvm, fermentation time2d, addition of defoamer0.1%(w/v), ventilation volume was adjusted acconding to real-timedissolved oxygen in fermentation process.