Bacillusthuringiensisandmodernbio-pesticidesOnPaperKeywordsBacillusthuringiensis;Research;problems;Solutions;prospectsAbstractsummarizesthediscoveryofBacillusthuringiensisandinsecticidalmechanismofBacillusthuringiensisResearch,researchproblemsandsolutionideasaredescribed,andtheapplicationofBacillusthuringiensisprospect.Newmicrobialpesticideproductionasapollution-freeagriculture,forestry,croppestanddiseasecontrolinthefuturetherewillbehugeinmarketdemand,furtheracceleratethedevelopmentofmicrobialpesticides,industrialandapplicationprocess,reducepesticideresiduesinagriculturalandagro-ecologicalenvironmentalpollutionandachievesustainablecontrolofpestsanddiseasesofmajorcrops,willhavehugesocial,economicandecologicalbenefits.ABacillusthuringiensis(Bt)insecticidalmechanismofthediscoveryand1.1Bacillus1thuringiensis(Bt)discoveryDegreein1901,Japanesescholarcomplexstonediseasefromtheriskofdamping-offisolatedlarvaetoproducecrystalsof1.10yearsofBacillusthuringiensisBerlinerfromGermanywhereadiseaseoftheMediterraneanflourmothflourinasimilarisolatedstrains,andofficiallynamedasBacillusthuringiensis(Bt).4yearslater,amannamedKeLinnuoscientistsfoundthatthebacteriacellscanformasquareordiamond-shapedcrystals,butunfortunatelythishasnotbeenfoundattentionuntil40yearslater,in1953,abiologistnamedHannahprovedthatthecrystalsaretoxicproteincrystals,itrevealsthepinkborercauseofdeath.In1920-1930,Btasamicrobialinsecticidemainlyusedtocontrolcornborer.1938No.1productsinFrancepreparationSporeineadventofbio-pesticidesfrombeginningtheprelude.HavebeenfoundlateronColeoptera,mites,Homoptera,Hymenoptera,Orthopterainsects,animalandplantparasiticnematodes,flagellates,amoebae,flukes,tapewormshavetoxiceffectofBtstrains.Afurtherstudyfound,BtisaGram-positive2bacteria,inaddition,itcaninsomeparasiticlarvaeofmothsandbutterflies,andeventheplantsurface.SecretedbyBacillusthuringiensisCrygenesencodedby,hasinsecticidalactivityofδ-toxin(orso-calledinsecticidalcrystalprotein)ofproteincrystalsforminsidethespores.CryproteinsofLepidoptera(mothsandsuchbutterflies),Diptera(suchasflies,mosquitoes)andColeoptera(beetles)areverydestructive,soBacillusthuringiensiscanbemadeefficientfermentationproductionofbio-pesticides,orusemadeofanti-Crygenegeneticallymodifiedpests.1.2Bacillusthuringiensis(Bt)insecticidalmechanismBacillusthuringiensis(Bt)hasbeenabletoinsecticide,isduetotheircellmemoryinatoxicprotein,calledparasporalcrystals,insectswillbeswallowedpoisonanddied,whilethelivingcellsandparasporalenvironmentallyfriendlynon-toxiccrystals,becausetheanimal’sgastrointestinaltract,theacidicenvironmentoftheproteincrystalcannotbedissolved,andthusharmlesstohumansandanimals,soitisasafeand3efficientbiologicalinsecticidesusedtokillavarietyofcropspest.Bacillusthuringiensis(Bt)insecticidalmechanismis:Bacillusthuringiensisinsectfeeding,thebacteriaintheirgastrointestinaltractproduceaproteincrystalendotoxin(δ-endotoxin),heat-stabletoxin(β-exotoxin),sawflytoxins(@-exotoxin)andBt-γexotoxinThesetoxinscanbeerosionofinsectintestinalcellstodestroytheintestinalliningandintotheblood,lymphtissue,sothatpestsbecauseofhungerandsepsisdied.BacillusthuringiensisisacontrolobjectLepidoptera,Hymenoptera,Diptera,Coleopteraandotherinsects,thepersistenceofitspotencyuptoabout7~10d.Requirespecialattentionare:Bacillusthuringiensis(Bt)anditspreparationforthehighlytoxicsilkworm,mu...