Bacteriocin From Leuconostoc Lactis(9)

Bacteriocins produced by lactic acid bacteria (LAB) as biological preservation have received more attention in recent years. As food-graded microorganisms, Leuconostoc sp. and Pediococcus sp. strains play an important role in modern food production. This paper investigates the ability of some strains from these two LAB to produce bacteriocins to be used potentially as biological agent according to recommended methods.1.Screening of High Bacteriocin-producing StrainThough the selection of indicative bacteria, primary screening and secondary screening of the Bacteriocin-producing Strain, we get L .lactis (9), Pediococcus acidilactici, L. mesenteroides subsp. dextranicum WZ30-2 and L. pseudomesenteroides WZ-9-2. Then, we choose L .lactis (9) as the continul use one.2.Optimization culture condition of L .lactis (9)After single factor test , we get the best culture condition of L .lactis (9). soya peptone was 1.5%, glucose was 2.0%, temperature 37℃; initial pH6.0-6.5 for 18h.3.Purification of the Bacteriocin product by L .lactis (9).Seek the technology of purification of the Bacteriocin product by L .lactis (9).And the bacteriocin's possible molecular weight no more than 14.2 kD,with likely 8kD according to SDS-PAGE analysis.4.Application Research of bacteriocin product by L .lactis (9) compare to Nisin.