1、AbstractSilkwormisan importanteconomic insect whichhasa great economic and social benefit.Microorganismsinsilkwormguthave animportantfunctionfortheirgrowthand microecologicalbalance.Mostreportsaboutsilkwormgutbacteria focused onthe structure oftheirmicroecosystemand noso
2、genesiswhile lessreportsabouttheirapplication inenzymeproducing bacteria at present.Amylase producing intestinalbacteria canhelp the host digeststarchorother nutrientsmore effectively.And these bacteria have some other probiotic functions.Inrecentyears,probioticsapplicat
3、ion inanimal microbial preparation concentratedinthe productionofaquatic and poultryproduction.Yetfew study wasaboutsilkwormprobiotics.Problemson low leave silk changing rate and high silkwormdisease incidencein Sericulture alwaysexisted,somakeresearchaboutsilkworm bacte
4、ria and theirenzyme production abilitythenmakea prokaryotic gene expression analysisaboutenzyme gene mayhave some significanceinimproving the silkwormgut microenvironmentand indevelopmentofsilkwormartificialdiet.Some culturable bacteria inlarvalgutsofthe Bombyxmoriat5thy
5、earphase were isolated and purified bytraditionalmethod.Twoamylaseproducing strainsofthem wasscreened though beefextract peptone starch medium.Enzymeproducing bacteria’s16SrDNAsequenceswere amplified and cloned withbacteria identification universal primersrespectively.Bl
6、asted these cloning sequenceswithsequencesexisted in GenBank,and the two strainsbothhave 99%homologywithBacilluscereus.Identified these strainswegot asBacilluscereuscombiningwithobservationoftheircolonyshape and observationoftheirindividual shape bymicroscope.Determining
7、 strains’amylase activitybyDNS method.Resultsshowed,enzymeproducedbythe silkwormgut bacteria had a certainactivity,and strains’16SrDNAsequenceswere alsodifferentfromsequencesexisted inGenBank,and thushassome significance. Primersofαamylase genes(Ec.3.2.1.1)weredesigned a
8、ccording to known genesafter identificationofisolated strains.Amylasegene sequenceswere amplified from
