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.

ISOLATION OF ROSMARINIC ACID FROM CALLUS OF PERILLA FRUTESCENS AND STUDIES OF ITS INHIBITION ON THE GROWTHS OF BACTERIA AND FUNGAL / 微生物学通报

Perilla frutescens callus were induced from leave explants on MS medium suplemented with NAA and 2,4-D. The Rosmarinic acid (RosA) content of dried callus was 0.85%. The RosA was extracted from the callus with 80% alcohol and purified through extraction with ethyl acetate and a Sephadex LH-20 column chromatography. The parity of the final product was 95% as analyzed by HPLC RosA could inhibit the growths of Escherichia colt, Staphylococcus aueris and Rhizotonia with MICs of 300, 400, 800?g/mL, respectively.