摘要
In the present study, eight strains were isolated from 20 cow vagina samples and identified using phenotype, biochemical analysis, sugar fermentation tests, and 16S rRNA sequence analysis. Among eight strains, only SQ0048 was identified as Lactobacillus johnsonii based on a series of biochemical testing (including the adhesion test, catalase test, bacteriocin production test, antibacterial test, and pH value), suggesting that its biological activity was superior to the other seven strains. Furthermore, SQ0048 had the lowest pH value (4.32) and the shortest fermentation time (8 h) compared with the other strains. The adhesion rate of SQ0048 was significantly higher than that of Lactobacillus delbrueckii, with an average adhesion number of 304 ± 2.67. The hydrogen peroxide production testing in SQ0048 was positive;in addition, bacteriocin gene of SQ0048, encoding an approximately 10-kDa product, was successfully cloned, expressed, and detected using the SDS-PAGE method. Meanwhile, SQ0048 had a weak inhibitory effect on Staphylococcus aureus and Escherichia coli. However, the expression products of the bacteriocin gene of SQ0048 had a very strong inhibitory effect on S. aureus and E. coli, with inhibition zone sizes of 18 ± 0.45 mm and 15 ± 0.60 mm, respectively. These data showed that SQ0048 has excellent antibacterial properties compared with other isolated strains and is a potential probiotic candidate to improve the health of the vaginas of cows by inhibiting pathogenic microorganisms.
In the present study, eight strains were isolated from 20 cow vagina samples and identified using phenotype, biochemical analysis, sugar fermentation tests, and 16S rRNA sequence analysis. Among eight strains, only SQ0048 was identified as Lactobacillus johnsonii based on a series of biochemical testing (including the adhesion test, catalase test, bacteriocin production test, antibacterial test, and pH value), suggesting that its biological activity was superior to the other seven strains. Furthermore, SQ0048 had the lowest pH value (4.32) and the shortest fermentation time (8 h) compared with the other strains. The adhesion rate of SQ0048 was significantly higher than that of Lactobacillus delbrueckii, with an average adhesion number of 304 ± 2.67. The hydrogen peroxide production testing in SQ0048 was positive;in addition, bacteriocin gene of SQ0048, encoding an approximately 10-kDa product, was successfully cloned, expressed, and detected using the SDS-PAGE method. Meanwhile, SQ0048 had a weak inhibitory effect on Staphylococcus aureus and Escherichia coli. However, the expression products of the bacteriocin gene of SQ0048 had a very strong inhibitory effect on S. aureus and E. coli, with inhibition zone sizes of 18 ± 0.45 mm and 15 ± 0.60 mm, respectively. These data showed that SQ0048 has excellent antibacterial properties compared with other isolated strains and is a potential probiotic candidate to improve the health of the vaginas of cows by inhibiting pathogenic microorganisms.
作者
Chao Cheng
Qiaozhen Tian
Shaofeng Su
Hui Zhang
Hongjie Guo
Pengfei Gao
Songhe Xu
Zhiguo Liu
Yanfen Ma
Zhenjun Li
Chao Cheng;Qiaozhen Tian;Shaofeng Su;Hui Zhang;Hongjie Guo;Pengfei Gao;Songhe Xu;Zhiguo Liu;Yanfen Ma;Zhenjun Li(School of Sciences Life, Jining Normal University, Jining, China;Shanxi Province Datong University, Datong, China;Inner Mongolia Academy of Agriculture and Animal Husbandry Sciences, Hohhot, China;Inner Mongolia Agricultural University, Hohhot, China;Vocational and Technical College of Ulanqab, Jining, China;National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, China;School of Agriculture, Ningxia University, Yinchuan, China)
