Fig. 5

Function and validation of Acinetobacter based on metagenomic analysis during tea saponin degradation process. TE and TL refer to tea saponin treated soil for 24 h and 72 h respectively. CE and CL substituted tea saponin feed for larvae for 24h and 72h, respectively. a, b Top 20 KEGG pathways showing significant differences in abundances when comparing the beginning and end of saponin degradation experiments in soil (a) and gut (b) samples. The larger the ordinate, the smaller the p value, indicating a more significant effect. The abscissa represents the proportion of up-down normalization (the difference between the number of up-regulated and down-regulated genes among the total differential genes). The more right-shifted this value is, the greater the difference between upregulated and downregulated genes enriched within the specified pathway, and the larger the number of upregulated genes that are present within that pathway. The left value indicates the difference between downregulated genes enriched in this pathway is larger than up-regulated genes, and thus, indicates greater downregulated gene numbers. The size of the points indicates gene counts. The orange line represents the p = 0.05 threshold. The 20 most abundant pathways are shown on the right, with different colors representing different pathway classes. c Acinetobacter genomes that could be assembled with genome binning analysis of gut and soil samples and corresponding annotations. The width of the line was determined according to the proportion of read numbers. d Verification of tea saponin degradation by Acinetobacter sp. (AS23) in vitro culture. Liquid medium was prepared using 5 g/L TS and the rest as described above. Each treatment group was cultured at 37 °C by adding 20 μL of a single bacterial solution with an OD value of 2.0 into 100 ml of medium, shaking at 200 rpm. The control group (CK) was cultured with 20 μL of sterile water under the same conditions. Samples were aseptically taken every 12 h, with 1 mL of solution, from each culture for saponin detection and repeated with five samples at each time point. Samples from 12, 36, and 60 h time points were used to measure residual TS content. e Verification of tea saponin degradation by Acinetobacter sp. (AS23) within weevil guts. Thirty larvae were treated with gentamicin sulfate, tetracyclines, and rifampin. After 24 h, cultured AS23 cells were mixed with sterile honey water and fed to larvae. Thirty larvae were divided into five groups and placed in 5 sg/L of TS fodder. After feeding for 7 days, larvae were removed, and feces were used to evaluate TS content