Expression of antimicrobial peptide Cecropin P1 in Saccharomyces cerevisiae and its antibacterial and antiviral activity in vitro

BACKGROUND: Cecropin P1, acting as an antimicrobial, has a broad-spectrum antibacterial activity with some antiviral and antifungal properties. It is a promising natural alternative to antibiotics which is originally isolated from the pig intestinal parasitic nematode Ascaris suum. Many studies have shown that Cecropin P1 is helpful for the prevention or treatment of clinical diseases. Therefore, it is very necessary to establish a safe, nontoxic, and efficient expression method of Cecropin P1. RESULTS: The results indicated that the recombinant protein was about 5.5 kDa showed by Tricine­SDS­ PAGE and Western blot. And Cecropin P1 was efficiently secreted and expressed after 12 h of induction, with an increasing yield over the course of the induction. Its maximum concentration was 7.83 mg/L after concentration and purification. In addition, in vitro experiments demonstrated that Cecropin P1 not only exerted a strong inhibitory effect on Escherichia coli, Salmonella sp., Shigella sp., and Pasteurella sp., but also displayed an antiviral activity against PRRSV NADC30-Like strain. CONCLUSIONS: Collectively, the strategy of expressing Cecropin P1 in Saccharomyces cerevisiae is harmless, efficient, and safe for cells. In addition, the expressed Cecropin P1 has antiviral and antibacterial properties concurrently.

Effects of Yucca Extract on Feed Efficiency, Immune and Antioxidative Functions in Broilers

Effects of yucca extract (YE) on feed efficiency, immune and antioxidative function in Arbor Acres broilers were studied. One hundred and twenty-eight fourteen-day-old broiler chickens were randomly divided into four treatments with four replicates of 8 birds each. These four diets were formulated by adding 0, 100, 200 and 300 mg/kg YE to the basal diet. The results showed that: diets supplemented with 100 and 200 mg/kg YE increased average body weight gain, feed efficiency, IgG, IgM, T-AOC, CAT and SOD levels, and have positive effects on inducing immune organs' maturation. In addition, 100 mg treatment mainly improved the feed efficiency whereas 200 mg treatment mainly acted on immunity and anti-oxidation. In conclusion, YE can be used as a feed additive due to its capability to improve feed efficiency, immune and antioxidative function in broilers.