Abstract:

【Objective】 The biological property of the recombinant antibacterial peptides Fowlicidin-3 and its application in animal husbandry were studied. 【Method】 According to the amino acid sequences of Fowlicidin-3 as described in the antibacterial peptide database, using the preferential condon of P. pastoris, the antibacterial peptide Fowlicidin-3 gene 114 bp in length was designed and synthesized by SOE PCR. The antibacterial peptide gene was cloned into the pPICZα-A vector to construct the recombinant expression vector pPICZα-A-F. The linearized plasmid pPICZα-A-F was transformed into P. pastoris X-33 by electroporation to construct the recombinant expression yeast strain. 【Result】 Fowlicidin-3 was successfully expressed and the concentration of the secreted antibacterial peptides reached up to 170 mg?L-1. Agrose diffusion assay showed that antibacterial peptide Fowlicidin-3 exhibited strong antibacterial abilities to E. coli K99 and Salmonella pullorum, the diameter of inhibition zone to E. coli K99 and Salmonella pullorum were 1.9 cm and 2.2 cm, respectively. The result also showed that the recombinant antibacterial peptides Fowlicidin-3 could be expressed and obtained with high level while the pH of the culturing BMMY medium was 6.0, the yeast was cultured under 29℃ for 72 hours and 2% methanol was supplemented into the medium. 【Conclusion】 The high level expression of antibacterial peptide Fowlicidin-3 with great biological activities was successfully constructed in yeast strain P. pastoris in this research.

Key words: fowlicidin-3')">fowlicidin-3, antibacterial peptide, SOE, Pichia pastoris, bacteriostasis experiment