To screen for Limosilactobacillus reuteri strains with excellent safety profiles and high antimicrobial activity, this study systematically evaluated the biosafety, carbohydrate metabolic characteristics, and antimicrobial potential of Limosilactobacillus reuteri GZMV125, a strain previously isolated and preserved in our laboratory, by integrating whole-genome analysis with multidimensional experimental validation, thereby exploring the genetic basis underlying its functional properties. Genomic analysis revealed that the strain harbors one circular chromosome and one plasmid. No critical virulence factors were identified, while a type Ⅲ polyketide synthase gene cluster was detected. Safety assessments confirmed that the strain exhibits no hemolytic activity, and its antibiotic susceptibility profile meets the safety criteria for probiotic strains, indicating favorable biosafety characteristics. Antimicrobial assays demonstrated that its cell-free fermentation supernatant exhibits significant inhibitory effects against a broad range of foodborne pathogens, with the strongest inhibition observed against Listeria monocytogenes. Carbohydrate metabolism studies showed that the strain can efficiently utilize diverse carbon sources, including glucose and xylose, and that its antimicrobial activity is regulated by carbohydrate availability. Xylose was identified as the optimal carbon source for inducing the strongest antimicrobial activity, which may be associated with increased viable cell density and enhanced acid production capacity resulting from carbohydrate utilization. These findings established a potential association among “genomic metabolic potential-carbohydrate utilization phenotype-antimicrobial function.” In conclusion, Limosilactobacillus reuteri GZMV125 exhibits excellent safety, broad-spectrum antimicrobial capability, and strong adaptability in carbohydrate utilization, demonstrating considerable potential for development as a probiotic formulation or food fermentation starter culture. This research provides a scientific basis and theoretical support for its food-grade industrial application.

This study aimed to obtain strains producing high levels of salt-tolerant protease from Aspergillus oryzae K9, isolated from high-salt liquid-state moromi, by combined mutagenesis induced by atmospheric and room temperature plasma (ARTP) and ultraviolet (UV) followed by domestication and screening using high-salt plates. The dominant mutant S-G27, whose neutral protease activity was increased by 35.82% compared with K9, was obtained after ARTP treatment of K9. The dominant mutant G-U2, whose neutral protease activity was increased by 56.81% compared with K9, was obtained after subsequent UV treatment of S-G27. In 15% NaCl solution, the residual activity of neutral protease from G-U2 was 1.94 times as high as that of K9. G-U2 exhibited good stability, and 92% of the initial enzyme activity remained after the seventh passage. Compared with the starting strain K9, G-U2 showed shorter mycelia, more spores, larger spore volume, and more surface ornaments. Mutagenesis did not induce the expression of aflatoxin-related genes, meeting production safety requirements. In simulated soy sauce fermentation experiments, the neutral protease activity, acid protease activity, and amino nitrogen content of G-U2 at the end of fermentation were 120.19%, 52.29%, and 18.37% higher than those of K9, respectively.