鱼虾中乳酸菌细菌素的筛选、鉴定及其特性研究OA

Objective To screen and identify bacteriocins produced by lactic acid bacteria(LAB)from fish and shrimp,and to analyze their biological characteristics.Methods In January 2024,a total of 100 samples of fish and shrimp feces or intestinal contents were randomly collected from various markets in Ganzhou City.Lactic acid bacteria were isolated and purified,and bacteriocin-producing strains were screened and identified by 16S rDNA sequencing.Subsequently,temperature tolerance and pH tolerance tests were performed to analyze the biological characteristics of the bacteriocins produced by the target strains.Results A total of 53 LAB strains(designated GZJKQCDC-1 to GZJKQCDC-53)were isolated from the 100 samples.Using Escherichia coli and Staphylococcus aureus as indicator organisms,four bacteriocin-producing LAB strains(GZJKQCDC-4,GZJKQCDC-15,GZJKQCDC-21,and GZJKQCDC-36)were screened.The strain exhibiting the most pronounced antibacterial activity,GZJKQCDC-21,was selected as the target strain and identified as Lactobacillus pentosus by 16S rDNA sequencing.Regarding biological characteristics,compared with the blank control group,the GZJKQCDC-21 strain retained relatively high antibacterial activity after treatment at 60 °C and 80 °C,with no statistically significant differences among the three groups(P>0.05).After treatment at 100 °C and 121 °C,the antibacterial activity of the GZJKQCDC-21 strain decreased,and the differences compared with the blank control group were statistically significant(P<0.05).Compared with the blank control group,the GZJKQCDC-21 strain retained relatively high antibacterial activity after exposure to pH 2.0,4.0,and 6.0 environments,with no statistically significant differences among the three groups(P>0.05).After exposure to pH 8.0 and 10.0 environments,the antibacterial activity of the GZJKQCDC-21 strain decreased,and the differences compared with the blank control group were statistically significant(P<0.05).Conclusion The bacteriocins produced by LAB isolated from fish and shrimp exhibit strong antibacterial activity,and their biological characteristics demonstrate potent thermal stability and pH tolerance.