CONSTRUCTION OF PARTIAL GENOMIC LIBRARY OF Bacillus subtilis AND SCREENING FOR RECOMBINANTS PRODUCING αAMYLASE, PROTEASE AND LIPASE

Genomic libraries contain a clone of every gene and extragenic sequences found in the cells of any organism and screening of the library is done to isolate clones that contain our gene of interest. Genomic libraries can be retained for many years and propagated and therefore it is a popular method of choice for maintaining every gene sequence of the organism whose gene library is being created. Since microbial production of enzymes is preferred due to easy genetic manipulation and availability, our aim was to construct a genomic library of Bacillus subtilis and then screening the recombinants that produced amylase (starch-hydrolyzing), protease (protein-hydrolyzing) enzymes and lipase (lipid hydrolyzing) which have many industrial applications. The vector used for cloning was pUC 18 and E.coliDH5α served as host cells. The recombinant cells were identified by biochemical characterization using starch agar plate, gelatine plate and lipid agar plate. The growth of colonies on plates of M9 minimal media together with the respective compound and the zone of clearing around the colony served as confirmatory test to detect the presence of recombinant organisms.