Screening and Safety Study of Antimicrobial Substance Producing Strains in Traditional Soybean Paste in Northeast China

The objective of this study was to isolate and identify microorganisms capable of producing antimicrobial compounds from Northeast China soybean paste and to analyse their antimicrobial capacity. The results showed that a total of 44 strains with antibacterial activity were isolated, mainly Bacillus spp. Of these, Bacillus velezensis R2 was identified as capable of inhibiting the growth of six foodborne pathogenic bacteria, with a broad spectrum of bacterial inhibition. Additionally, non-ribosomal lipopeptides encoding bacillomycin D, fengycin, flagellin, iturin A, bacilysin, surfactin, and the protein class TasA were amplified from B. velezensis R2. The functional, phenotypic and safety-related characterization of B. velezensis R2 revealed that it was non-hemolytic, sensitive to 10 antibiotics, and possessed protease amylase, cellulase, and pectinase activities. This study aims to provide a reference for the high-value utilization of low-salt fermentation microbial resources of sauces. © 2024 Chinese Institute of Food Science and Technology. All rights reserved.