Abstract
The gene for maltohexaose-forming amylase (G6-amylase) from alkalophilic Bacillus sp. H-167 was cloned into Escherichia coli HB101 using pBR329 as a cloning vector. Recombinant pi as mid, pSB404, containing a 3.0kb fragment derived from H-167 DNA, was shown to direct the synthesis of G6-amylase, which was partly secreted into the culture broth on the addition of a certain carbohydrate. The pH- and temperature-activity profiles of the G6-amylases from HB101 (pSB404) and H-167 were essentially the same. The G6-amylase produced by HB101 (pSB404) was observed to be multiform as well as H-167; the molecular weights were 90, 000, 73, 000 and 60, 000, respectively. Protease inhibitor experiments showed that the multiple expression was due to intracellular proteolysis of the enzyme.
