A novel α amylase gene was amplified from Sulfolobus shibatae by using PCR technique. The amplified 1.7kb DNA fragment was inserted into an expression vector pBV220 to yield the recombinant plasmid pSBAM. The novel α amylase gene in pSBAM was expressed in E. coli . The production of the novel α amylase activity reached over 8 units/100mL of the culture. The molecular weight of this enzyme was about 61kD by SDS PAGE. The expressed novel α amylase protein in E.coli DH5α accounted for about 20% of the total protein in the recombinant cell. The cooperative action of the novel α amylase and the maltooligosyltrehalose synthase from Sulfolobus shibatae was investigated and trehalose was detected by using HPLC analysis when using amylose and partial starch hydrolysates as substrates.
