A 4.6-kb HindIII fragment encompassing the complete 140-kDa ${alpha}$-amylase gene of Lactobacillus amylovorus B 4540 was cloned into pBR322 by the shot gun method. Southern blotting and restriction mapping for the insert were performed. The recombinant 9.0-kb plasmid, pFML1, conferred ${alpha}$-amylase activity to E. coli and Lactococcus lactis hosts when introduced by electroporation. SDS-PAGE and zymography confirmed the production of 140-kDa ${alpha}$-amylase and its proteolytic degradation products with enzyme activity in transformants. Total ${alpha}$-amylase activity of E. coli $DH5{alpha}$ cells harboring pFML1 was 1.8 units and most activity was detected from cell pellets. Total enzyme activity of L. lactis subsp. lactis MG1363 transformant was five to ten-fold lower than that of E. coli cell but more than half of the activity was detected in the culture supernatant.