Abstract:Abstract：To screen out a lactic acid bacterium producing broad-spectrum bacteriocin，traditional Chinese cabbage was used as the research object to isolate the lactic acid bacteria based on classical Lactobacillus screening method and 16S rRNA gene sequencing.Biological properties of antibacterial substance were analyzed based on protease stability，thermal stability，pH stability and inhibition spectrum.The result showed that one strain of lactic acid bacterium named SY5 was isolated from the traditional Chinese cabbage，and identified as Lactobacillus pentacose.When the supernatant of SY5 culture was treated with protease K and pepsin，its antibacterial activity was lost，indicating that the antibacterial component was a kind of protein and was identified as a bacteriocin.The analysis of biological characteristics showed that the bacteriocin remained 82.7%antibacterial activity at 120℃for 30 min，and the ranges of pH stability were from 2 to 7.The results of the bacteriostasis assay showed that the bacteriocin had a good inhibitory effect on a variety of Gram-positive bacteria and Gram-negative bacteria，indicating its broad-spectrum antibacterial activity.