Screening of Lactic Acid Bacteria Tolerant to Antimicrobial Substances and Their Effects on the Quality of Cyperus esculentus Silage

Abstract

This study investigated the inhibitory effects of endogenous compounds from Cyperus esculentus on lactic acid bacteria and examined whether inoculation with selected strains could enhance silage fermentation quality. Lactic acid bacteria were isolated and identified from C. esculentus silage, and antibacterial assays were performed to screen strains suitable for inoculation. Results indicated that the endogenous compounds inhibited lactic acid bacteria, with sensitivity ranked as Lentilactobacillus buchneri > Lactiplantibacillus plantarum > Lacticaseibacillus rhamnosus. Scanning electron microscopy revealed no significant structural damage to bacterial cells caused by the inhibitory compounds. Metabolomic analysis suggested that these compounds may alter lactic acid bacterial metabolism by modulating key pathways, including amino acid and energy metabolism. Among the tested strains, Lcb. rhamnosus exhibited the highest tolerance to the endogenous compounds. Inoculation experiments demonstrated that the addition of Lcb. rhamnosus significantly enhanced the fermentation quality of C. esculentus silage.