Comprehensive profiling of the metabolome in corn silage inoculated with or without Lactiplantibacillus plantarum using different untargeted metabolomics analyses

ABSTRACTSilage fermentation is a complicated biochemical process involving interactions between microbes and metabolites. However, the overall metabolome feature of ensiled forage and its response to lactic acid bacteria inoculation is poorly understood. Hence, in this study metabolome profiles of whole-plant corn silage inoculated with or without Lactiplantibacillus plantarum were characterised via solid-phase microextraction/gas chromatography/mass spectrometry (SPME-GC-MS), gas chromatography/time-of-flight mass spectrometry (GC-TOF-MS), and Liquid chromatography/Q Exactive HFX mass spectrometry (LC-QE-MS/MS) analysis. There were 2087 identified metabolites including 1143 reliably identified metabolites in fresh and ensiled whole-plant corn. After ensiling, the increased metabolites in whole-plant corn were mainly composed of organic acids, volatile organic compounds (VOC), benzene and substituted derivatives, carboxylic acids and derivatives, fatty acyls, flavonoids, indoles and derivatives, organooxygen compounds (including amines and amides), phenols, pyridines and derivatives, and steroids and steroid derivatives, which includes neurotransmitters and metabolites with aromatic, antioxidant, anti-inflammatory, and antimicrobial activities. Phenylacetaldehyde was the most abundant aromatic metabolite after ensiling. L-isoleucine and oxoproline were the major free amino acids in silage. Ensiling markedly increased the relative abundances of 3-phenyllactic acid, chrysoeriol, 6-O-acetylaustroinulin, acetylcholine, γ-aminobutyric acid, pyridoxine, and alpha-linoleic acid. Inoculation with L. plantarum remarkably changed silage VOC composition, and essential amino acids, 3-phenyllactic acid, and cinnamaldehyde compared with untreated silage. The present study does not only provide a deeper insight into metabolites of the ensiled whole-plant corn but also reveals metabolites with specific biological functions that could be much helpful in screening novel lactic acid bacteria to well ensile forages. Inoculation with L. plantarum significantly affects the metabolome in ensiled whole-plant corn.KEYWORDS: Untargeted metabolomicsLactiplantibacillus plantarumcorn silagemetabolome AcknowledgmentsWe thank the assistance for untargeted metabolomic analysis from Shanghai BIOTREE Biological Technology Co., Ltd., Shanghai, China.Disclosure statementNo potential conflict of interest was reported by the author(s).Authors on contributorRina Su: Methodology; software; validation; formal analysis; investigation; data curation; writing – original draft preparation; writing – review and editing. Wencan Ke: Methodology; investigation; data curation. Jie Bai: Investigation; writing – review and editing. Musen Wang: Resources; investigation. Samaila Usman: writing – review and editing. Dongmei Xie: Investigation; writing – review and editing. Dongmei Xu: Writing – review and editing. Mengyan Chen: Investigation. Xusheng Guo: Conceptualisation; resources; writing – review and editing; supervision; administration; funding acquisition.Supplementary materialSupplementary data for this article can be accessed at https://doi.org/10.1080/1745039X.2023.2247824Data availability statementThe data related to the result of this study are available from the corresponding author upon reasonable request.Additional informationFundingThis work was supported by the Joint Funds of the National Natural Science Foundation of China (U20A2002).