Expression and Purification of Nisin in Escherichia coli
International Journal of Life-Sciences Scientific Research
Fusion expression is a promising strategy for the production bioactive peptides in Escherichia coli to enhance either soluble protein level or purification potential. Nisin is the bacteriocin that had been extensively studied and had been widely applied in many areas such as food, pharmaceutical. However, scientific reports on recombinant nisin production in E. coli are still insufficient. In this study, we constructed a new expression plasmid containing the coding sequence of NusA,
... f NusA, hexahistidine and Lactobacillus lactic nisin coding sequence. Next, we introduced the expression plasmid into BL21 E. coli and produced the recombinant fusion nisin in E. coli. Recombinant E. coli extract was purified by nickel affinity chromatography and resulted in 77% yield with 55% purity. The bioactive nisin was successfully released from NusA-6xHis-Nisin fusion protein by the endonuclease. The nisin showed its antibacterial activity on Listeria monocytogenes with activity unit of 18.9 AU/mg. The nisin bioactivity is stable at the temperature range of 30-90 o C and in pH range of 1-12. The results showed that the new construction was appropriate for production of nisin bioactive peptides. Expression, collection and purification of nisin-E. coli BL21 (DE3) was a well-known host strain for expressing recombinant protein such as: fast high-density cultivation, inactivate protease genes and containing hsd S (rB -, mB -) which help to maintain plasmid in the E. coli cell [30, 31] . In order to express nisin peptides in E. coli, the E. coli BL21(DE3) was used as host strain. The recombinant strain E. coli BL21 (DE3)/pET43.1a-kN then Int. J. Life. Sci. Scienti. Res.