Study on isolation and identification of a strain of Enterococcus faecium producing L-lactic acid,optimization of culture conditions and probiotic properties
CHEN Lingyu
CHENG Yuan
DIAO Wentao
LI Zhijian
LIU Dehai
Abstract：The study aimed to screen probiotic strains with high L-lactic acid production.A strain of Enterococcus faecium producing L-lactic acid was isolated from the fresh feces of piglets.It was identified through morphological observation,physiological and biochemical characteristic analysis,and 16S rDNA sequencing.The culture conditions were optimized,and tests such as acid resistance,bile salt resistance,and antibacterial properties were used to determine the probiotic characteristics of the strain.The results showed that through morphological observation,analysis of physiological and biochemical characteristics,and 16S rDNA sequencing,the strain was identified as Enterococcus faecium and named HKS023.Under the conditions of an inoculation amount of 3%,a culture temperature of 37℃,an initial pH value of the culture medium of 6.3,a loading amount of 80 mL,and a shaker speed of 200 r/min,the viable bacterial count of the HKS023 strain was the highest after 24 hours of culture.The results of the antibacterial test showed that the HKS023 strain had inhibitory effects on Salmonella,Escherichia coli and Staphylococcus aureus.The results of the stress resistance test show that the HKS023 strain has a strong ability to tolerate acid and bile salts.The study indicates that the Enterococcus faecium strains isolated in the experiment have good probiotic properties such as acid resistance,bile salt resistance and antibacterial properties,and can be used as candidate strains for microbial feed additives.
Keywords：L-lactic acidbacteriaEnterococcus faeciumisolationidentificationantibacterial properties
Publication Date：2025-05-28
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：6( 74-79 )