The potential efficacy of lemongrass (Cymbopogon citratus) in improving the overall quality and fermentative stability of corn straw silage

Abstract

Improving silage quality and inhibiting undesirable microbes are key challenges in crop straw ensiling. This study investigated the effects of lemongrass (Cymbopogon citratus) with or without lactic acid bacteria (LAB, Lactobacillus plantarum), on corn straw silage. After 60 days, fermentation parameters, protein content, antioxidant activity, and microbial communities were assessed. Lemongrass markedly enhanced silage quality (p < 0.05), especially combined with LAB additive, by lowering pH, neutral and acid detergent fibers, and ammonia nitrogen, while increasing crude protein, total phenolics, total flavonoids, and desirable microbes. Antioxidant capacity was improved, and harmful microbes, including molds, Enterobacter and Klebsiella, were suppressed. 16 S rRNA and PICRUSt2 analyses showed that lemongrass reduced bacterial richness and core OTUs, with Firmicutes dominating at 10 %, and Proteobacteria and Bacteroidetes suppressed. Functional genes for sugar transport, osmoprotection, and oxidative stress were enriched, while peptide/iron uptake and transposases were repressed. Lactobacillus abundance reached 81 % in silages with 10 % lemongrass and additional LAB inoculant, and 72 % without LAB, respectively. In conclusion, integrating appropriate lemongrass and LAB supplements in corn straw silage can be served as an alternative strategy for improving the fermentation quality and stability.