Isolation and Screening of Broad-spectrum Antibacterial Substance-producing Lactobacillus Strains.

[Objective]This study aimed to screen broad-spectrum antibacterial substance-producing Lactobacillus strains and provide scientific reference for food preservation. [Method] Using homemade pickles as experimental materials, Lactobacillus strains were preliminarily isolated with BCP culture medium containing bromocresol purple; Lactobacillus supernatant was prepared using MRS medium containing CaCO3; subsequently, Lactobacillus strains with antibacterial activity against four indicator bacteria were obtained; after eliminating the interference of acid and hydrogen peroxide, antibacterial active strains were re-screened by thermal stability test and activity persistence test. [Result] After preliminary screening and re-screening, five Lactobacillus strains with antibacterial effects against Escherichia coli, Bacillus subtilis, Staphyloccocus aureus and Saccharomyces cerevisiae were obtained. To be specific,LP-6 strain exhibited significant antibacterial activity after eliminating the interference of acid and hydrogen peroxide. Results of thermal stability test and activity persistence test indicates that the fermentation supernatant of LP-6 strain still had significant antibacterial activity after heating at 121 °C for 15 min and after preservation for three months. [Conclusion] LP-6strain can produce bacteriocin-like antibacterial substances with wide application value in food industry. [ABSTRACT FROM AUTHOR]