摘要
A new bacteriocin(Y19-2)was isolated,purified,and characterized from Nanjing Steamed Roast Duck,a traditional Chinese fermented meat product.Purification was performed via ammonium sulfate fractional precipitation,diethyl aminoethyl(DEAE)-52 cellulose ion-exchange chromatography,Sephadex G-50 chromatography,and reversed-phase high-performance liquid chromatography(RP-HPLC).SDS-PAGE analysis showed the molecular weight of Y19-2 is 20 kDa,making it fall into the third type of bacteriocin based on the classifications of bacteriocins according to their molecular weights.In addition,Y19-2 is heat-resistant as suggested by a merely 14%loss of its antibacterial activity when heated at 121°C for 30 min.In acidic conditions(pH 3–5),Y19-2 has obvious antibacterial activity against both gram-positive and gram-negative bacteria,and such an activity can be partially inactivated by pepsin and trypsin while being completely inhibited by papain.Scanning electron microscopy and differential thermal scanning analysis showed that Y19-2 could inhibit bacteria growth by destroying the bacterial cell wall and affecting the synthesis of bacteria's nucleic acids.Therefore,Y19-2 is potential as a bioprotective agent in foods.
基金
supported by the Plan of Science and Technology Development of Jilin Province[Grant No.20140204010NY].
