一株烟草青枯病生防菌的筛选鉴定及其发酵优化.pdf

一株烟草青枯病生防菌的筛选鉴定及其发酵优化ScreeningandFermentationOptimizationofAntagonisticBacillusagainstTobaccoBacterialWiltZHAOXiao-yan1YANGHuan2CHENJian-gang1WANGChang-jun3JIZhi-xia1CHENShou-wen1(1.StateKeyLaboratoryofAgriculturalMicrobiologyHuazhongAgriculturalUniversityWuhan430070China;2.WuhanLeyangBiotechnologyCo.Ltd.Wuhan430071China;3.HubeiTobaccoResearchInstituteWuhan430030China):OnebacterialstrainwasscreenedforitsantagonisticactivityagainstRalstoniasolanacearumbasedonthesizeofthebacteriostaticcircleinvitrobythedualcultureandculturefiltratetestsandnamedasXLA03.Itsbacteriostaticcirclecouldreach13mm.Accordingtodeterminationandanalysisof16SrDNAthestrainXLA03wasidentifiedasBacillusamyloliquefaciens.Basedonthesinglefactorexperimentsandorthogonalermentationmediumforitsbiexperimentsanoptimalfomass—productioninflaskswascomposedofmaizestarch15.0g/Lsoybeanmeal50.0g/LK2HPO4?3H2O1.0g/LMgSO4?7H2O0.75g/LMnSO4?H2O0.01g/L.TheoptimalfermentationconditionwasinitialpHof7.0inoculumsizeof1％loadedliquidof20mL/250mL.Keywords：tobaccobacterialwilt；Bacillusamyloliquefaciens；screening；fermentationoptimization烟草青枯病［病原物为茄科雷尔氏菌(Ralstoniasolanacearum)］是一种典型的维管束病害最显著的发病症状是烟草植株出现枯萎现象危害期大多出现在烟草旺长期或者旺长期以后根、茎、叶部均会受害［12］。经常发病产烟区的老病田或旱地烟田几乎每年都会发生形成绝产无收和全田发病的现象造成大面积烟草产量、品质下降制约着烟草产业的发展［3］。目前防治烟草青枯病的方法主要包括化学防治、生物防治、加强栽培管理和选用优质的抗病品种［4-7］但这些方法均无法杜绝该病的发生。生产过程中一般以种植抗性烟草品种和轮作为基础同时加强大田栽培管理通过化学药物辅助保护的综合防治技术控制病害发生。由于消费者对烟草品质的要求逐步提高对烟草成熟期病害的防治不宜采用有残留的化学药剂而使用拮抗细菌防治植物病害能达到无公害防治的目的［89］国内外关于拮抗细菌防治植物青枯病的报道涉及的生防细菌主要有芽孢杆菌、假单胞菌、链霉菌等。其中芽孢杆菌是一类