Cloning, overexpression of prelac gene encoding bacteriocin production of lactobacillus plantarum in escherichia coli

Abstract

The PreLac gene encodes bacteriocin production of Lactobacillus Platarum. In this study, PreLac gene was expressed in E. coli BL21 (DE3), using pET 21 a (+). The expression of PreLac occured under 1mM IPTG within 2 to 4 hours, was detected on SDS-PAGE at 40 kDa. To confirm the expression, the protein was purified on affinity chromatography and showed the His-Tag protein corrsponding to 40 kDa. The E. coli BL21 (DE3) harboring PreLac was used to test for the antimicrobial activity, antibiotic resistance, using disc diffussion method. The results showed the resistance of E. coli BL21 (DE3) harboring PreLac to three kinds of tested antibiotics such as chloramphenicol (16 μg /ml), tetracycline (64 μg /ml), sulbactam (512μg/ml). The cell free supernatant showed antimicrobial activities on Bacillus subtilis, Salmonella typhi, Pseudomonas aeruginosa, and Staphylococcis aureus. The study reported the expression and function of the PreLac gene of Lactobacillus plantarum. PreLac could play a role in bacteriocin production. Key words: Bacteriocin, Lactobaciillus plantarum, gene expression, antimicrobial activity