Screening and identification of broad spectrum bacteriocin-producing lactic acid bacterium

Thirty six lactic acid bacteria were isolated from meat stored in low temperature,and one which showed strong inhibitory activity against the indicated bacteria were screened through agar diffusion test.The supernatant of this strain could inhibit the growth of indicator strain strongly after excluding hydrogen peroxide and organic acid.But the inhibitory activity decreased sharply after treatment with pepsin,which indicated that this inhibitory material obtained the feature of protein,it could be classified as bacteriocin.The test of bacterial inhibition spectrum proved that the supernatant of this strain could inhibit not only gram-positive bacteria but also gram-negative bacteria and yeast.Therefore,this strain produced a bacteriocin with wide inhibition spectrum.Through detection of its appearance,physiological and biochemical characteristics,it was identified as Lactobacillus mali.