Temporal metabarcoding of a lignocellulolytic bacterial consortium unveils compositional, structural, and potential functional adaptations

Lignocellulosic biomass is a key resource for sustainable energy, but its complex structure poses challenges for degradation. Microbial consortia offer a robust solution due to their collective metabolic capabilities; however, understanding their adaptation over time is crucial for optimizing industrial processes. This study investigated the temporal dynamics of a soil-derived bacterial consortium during early (2-week) and late (20-week) stages of exposure to a lignocellulosic substrate. Using 16S rRNA gene metabarcoding, we compared community composition, diversity, and predicted functional profiles across degradation time points (days 0, 5, and 10). Results revealed significant taxonomic shifts, with adaptive stage and degradation day explaining approximately 70 % of community variance (PCoA). Although both stages began with similar ASV richness (early: 287.33 ± 15.01; late: 286.67 ± 37.29), the early stage was characterized by the dominance of a few taxa, whereas the late stage presented greater evenness and a more balanced functional profile. This compositional reorganization occurred alongside a broadly conserved predicted functional potential, with over 96 % of predicted KEGG Orthologs (KOs) shared between stages, suggesting functional redundancy. Despite this conservation, 2215 KOs were differentially abundant, primarily within carbohydrate, amino acid, and xenobiotic metabolism pathways, with nearly 65 % becoming more abundant in the late stage. Our findings demonstrate that while taxonomic composition evolves, the predicted functional potential remains relatively stable, a key trait for developing resilient biotechnological applications. • Microbial consortia adapt to lignocellulose with major taxonomic shifts over time. • Functional potential is conserved (>96 %) despite taxonomic changes, suggesting redundancy. • Late-stage adaptation favors carbohydrate and xenobiotic metabolism pathways. • Community structure changes, but functional redundancy ensures metabolic stability.