Screening Of Bacteriocin-producing Lactic Acid Bacteria In Mongolian Dried Beef And Its Physicochemical Characteristics

The 28 strains of lactic acid bacteria was isolated from Mongolian dried beef.The antibacterial activity of 28 strains of lactic acid bacteria were detected by escherichia coli,staphylococcus aureus and mononuclear hyperplasia liszt as indicator bacteria.There are 2 strains of lactic acid bacteria on the strongest bacteriostasis ability of the three kinds of indicator bacteria,and after pepsin and proteinase K treatment,the 2 strains of lactic acid bacteria producted bacteriocin.The 37X-3 produced pediococcus pentosaceus,37X-13 produced acidilacticipediocin by the identification of phenotype,physiological,biochemical and genetic type.The 2 pediocin can inhibit the growth of the three kinds of indicator bacteria and have the strongest bacteriostasis of mononuclear liszt in the pH of 2?6.The bacteriostatic activity of 2 pediocin had no significant difference(p<0.05)with control group after ultraviolet ray,magnesium sulfateand organic solvent treatment,but by EDTA.The bacteriostatic activity of 2 pediocin enhanced obviously(p>0.05).The bacteriostatic activity of pentosaceus pediocin(37X-3)appeared the highest peak at 24h,the bacteriostatic circle diameter of escherichia coli,staphylococcus aureus and mononuclear hyperplasia liszt were respectively 13.42 mm,14.49 mm and 15.34 mm.The bacteriostatic activity of acidilactici pediocin(37X-13)appear at 6h,the bacteriostatic circle diameter of escherichia coli and staphylococcus aureus were respectively 8.31 mm and 8.34mm,and was the highest peak at 24h,the bacteriostatic circle diameter of escherichia coli,staphylococcus aureus and mononuclear hyperplasia liszt were respectively 14.22 mm,14.19 mm and 16.27 mm.The 2 pediocin can sterilize mononuclear hyperplasia liszt and inhibit the growth of the escherichia coli and staphylococcus aureus.The protein content of pentosaceus pediocin(37X-3)and acidilactici pediocin(37X-13)were respectively 107.02 mg/mL and 139.59 mg/mL.byBCA kit determination.The 2 pediocin is small molecular peptides because the protein molecular weight of pentosaceus pediocin(37X-3)isless than 5KDa,and the protein molecular weight of acidilactici pediocin(37X-13)is less than 10KDa by Tris-Trince-SDS-PAGE.