Purification of an Antiviral Substance Produced by Alteromonas sp. and Its Virucidal Activity against Fish Viruses

Abstract

An antiviral substance of a high molecular weight, low cytotoxity and potent virucidal activity was purified from the culture supernatant of a marine Alteromonas sp. 48HS-27. Maximum production of this antiviral substance by the strain in MCYG broth was attained by 72 h-incubation at. 25°C. By the purification procedure involving ultrafiltration, precipitation with ammonium sulfate and acetone, gel filtration and native-polyacrylamide gel electrophoresis (PAGE), a polypeptide (48HS-27A) with antiviral activity was obtained at a 270-fold purification with 6.20% yield from the culture supernatant. Molecular weight of the purified 48HS-27A was estimated as approximately 52 kDa by both native and sodium dodecyl sulfate (SDS) PAGE. The 50% infection inhibitory concentrations of this substance were from 0.09 to 2.51μm/ml against one herpesvirus and five rhabdoviruses, whereas the minimal cytotoxic concentration of the substance was 144μm/ml against FHM and CHSE-214 cells. The purified 48HS-27A had proteolytic activity against casein and bovine serum albumin.