[Expression of Paenibacillus macerans cyclodextrin glycosyltransferase in Pichia pastoris and Bacillus subtilis]

The cgt gene was isolated from Paenibacillus macerans by PCR amplification and was inserted into vectors of pPIC9K and pMAS. The recombinant vectors were transformed to Pichia pastoris KM71 and Bacillus subtilis WB600, respectively. The results showed that alpha-CGTase activity in the culture media of recombinant P pastoris was only 0.2 U/mL, while it was 1.9 U/mL in recombinant B. subtilis. In addition, we optimized the culture conditions of the recombinant B. subtilis strain. After cultivation at 37 degrees C for 24 h with shake flask, the CGTase forming activity in culture media reached to 4.5 U/mL (hydrolysis activity was 3200 IU/mL), which is 9.8-fold to that of the original strain P. macerans.