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,die...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.展开更多
Positive effects of fermented foods consumption on humans have stimulated lots of research attention.The aim of this study was to determine the effect of Lactobacillus paracasei M-8R on the physicochemical and antioxi...Positive effects of fermented foods consumption on humans have stimulated lots of research attention.The aim of this study was to determine the effect of Lactobacillus paracasei M-8R on the physicochemical and antioxidant properties of mead during its fermentation.The mixed fermentation mead with Lactobacillus paracasei M-8R had an alcohol content of 17%,higher total polyphenols(107.14 mg GAE/L)and total flavonoids(74.53 mg RE/L)and the highest antioxidant capacity.The control sample(fermented only by yeast)was successive:11.2%,94 mg GAE/L and 68.74 mg RE/L.The most abundant volatile flavor compounds(80 species)were detected in the mead fermented by Saccharomyces Only.Combined with sensory evaluation,the mixed fermentation of Saccharomyces cerevisiae G10 and Lactobacillus paracasei M-8R is considered as the more promising fermentation method for mead production.展开更多
基金supported by the Plan of Science and Technology Development of Jilin Province[Grant No.20140204010NY].
文摘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This work was supported by the Plan of Science and Technology Department of Jilin Province of China[20210202057NC].
文摘Positive effects of fermented foods consumption on humans have stimulated lots of research attention.The aim of this study was to determine the effect of Lactobacillus paracasei M-8R on the physicochemical and antioxidant properties of mead during its fermentation.The mixed fermentation mead with Lactobacillus paracasei M-8R had an alcohol content of 17%,higher total polyphenols(107.14 mg GAE/L)and total flavonoids(74.53 mg RE/L)and the highest antioxidant capacity.The control sample(fermented only by yeast)was successive:11.2%,94 mg GAE/L and 68.74 mg RE/L.The most abundant volatile flavor compounds(80 species)were detected in the mead fermented by Saccharomyces Only.Combined with sensory evaluation,the mixed fermentation of Saccharomyces cerevisiae G10 and Lactobacillus paracasei M-8R is considered as the more promising fermentation method for mead production.
