Cloning and expression of thermostable β-amylase gene of thermoanaerobacterium thermosulfurogenes in Escherichia coli and Bacillus subtilis BR151 [Thermoanaerobacterium thermosulfurogenes'e ait si{dotless}cakli{dotless}ǧa dirençli β-amilaz geninin Escherichia coli ve Bacillus subtilis BR151'de klonlanmasi{dotless} ve ekspresyonu]

Dna fragment encoding thermostable β-amylase gene from thermoanaerobacterium thermosulfurogenes was amplified by pcr and then cloned into pbluescript ii ks/sk,pbt10,pnw33n and pub110 plasmids. recombinant plasmids were designated as pbluescriptβ,pbt10β,pnw33nβ and pub110β respectively. pbluescriptβ,pbt10β and pnw33nβ recombinant plasmids were transferred into escherichia coli,and pub110β was electrotransformed into bacillus subtilis br151. insert and pcr analysis of recombinant plasmids from e. coli and b. subtilis confirmed the 1935 bp β-amylase gene fragment on agarose gel electrophoresis. on lb-starch-agar plates,all recombinant e. coli colonies showed positive zones with i2 staining. although thermostable β-amylase gene was cloned in b. subtilis br151,the enzyme activity was not detected on lb-starch-agar plate. but after renaturation of extracellular proteins from b. subtilis on sds-starch-page,β-amylase enzyme regained enzymatic activity by zymogram technique and thereby confirmed that enzyme was not folding properly in b. subtilis host.