Abstract
To compare the gene expression of the alkalophilic Bacillus penicillinase in Escherichia coli and Bacillus subtilis, we constructed a shuttle plasmid, pSAP21, from PUBHOand pEAPl containing pMB9and the penicillinase gene of alkalophilic Bacillus No. 170. When pSAP21 was transformed in E. coli, ampicillin resistant transformants (20μg/ml) could be obtained by direct selection. The penicillinase gene was also expressed in B. subtilis carrying pSAP21. Although an ampicillin resistant transformant could not be obtained directly in B. subtilis, kanamycin resistant transformants carrying pSAP21 exhibited ampicillin resistance (10μg/ml) with the replica method. Most of the penicillinase produced was found in the culture media of E. coli and B. subtilis. The penicillinase produced by E. coli carrying pSAP21 did not decrease on prolonged cultivation. On the other hand, the penicillinase produced by B. subtilis carrying pSAP21 became maximumafter 20 hours cultivation and then decreased rapidly.
