Abstract:The twigs of Ligustrum robustum (Rxob.) Blume are the waste generated during the production of small leaf Kuding tea. The large quantity of waste is typically incinerated, resulting in significant environmental pollution and resource waste. To promote the resource utilization of the twigs of Ligustrum robustum (Rxob.) Blume, Lactobacillus plantarum was used to ferment its water extract, and then the composition, distribution and changes of the substances before and after the fermentation were detected by LC-MS non-targeted metabolomics technology. Multivariate statistical analysis methods including PCA and PLS-DA identified 175 different metabolites that demonstrated significant changes in metabolites before and after the fermentation of Ligustrum robustum (Rxob.) Blume twigs extracts, with 100 up-regulated and 75 down-regulated. The top 25 differential metabolites in univariate statistics included 3 peptides, 1 carbohydrate, 4 nucleic acids, 1 lipid, 1 organic acid, 1 flavonoid, and 14 other metabolites, involving 11 significantly different metabolic pathways, of which 6 were amino acids metabolic pathways. The differential metabolites included 915-fold increased Nobiletin and 11-fold enhanced Anserine, both of which have physiological activities such as antioxidant, anti-inflammatory, anticancer, and hypoglycemic effects. Meanwhile, the content of antibiotics Gentamicin. C1a and Lincomycin after fermentation were increased by 22 000 times and 66 times, respectively. The results demonstrate that Lactobacillus plantarum fermentation technology for the resource utilization of Ligustrum robustum (Rxob.) Blume twigs is feasible, but further safety assessment is required.
