Isolation,identification and growth characteristics of lactic acid bacteria with antibacterial activity
Using Bacillus subtilis,Escherichia coli and Proteus vulgaris as indicator bacteria,lactic acid bacteria with antibacterial activity were screened from traditional fermented food by traditional culture separation method combined with Oxford cup method.The stability of the fermentation super-natant and growth characteristics of screened strain were studied,and identified by molecular biology technology.The results showed that 4 strains of lactic acid bacteria with good antibacterial activity were obtained,which were numbered as Y1,Y4,Y14 and Y15.The fermentation supernatant of the 4 strains could inhibit the growth of the 3 indicator bacteria.Among them,the antibacterial activity of strain Y1 was better,the antibacterial circle diameter of the 3 indicator bacteria was＞13 mm,and the antibacterial activity of the fermentation supernatant was＞69％after treatment at 60 ℃ and 100 ℃.The antibacterial activity of the supernatant of strains Y1,Y14 and Y15 was still＞67％after acid alkali treatment.The growth curves of the 4 strains were correlated with acid-producing characteristics and antibacterial activities.The diameter of antibacterial zone tended to be stable after entering the stable period,and fermentation could be stopped at 12-18 h.The 4 strains all grew well at pH 5.0-7.0,and the optimal pH was 6.0.Among them,the strain Y15 had better acid and permeability tolerance,the strain Y1 had better alkali tolerance.Strains Y1 and Y4 were identified as Lacto-bacillus fermentum,and strains Y14 and Y15 were Lactiplantibacillus plantarum.
traditional fermented foodlactic acid bacteriaantibacterial activityisolationscreeninggrowth characteristicidentification
万方数据
维普
