Distribution patterns and community assembly processes of generalists and specialists in river affected by wastewater discharge from distilleries in typical Chinese spirits production area in China

Introduction: Understanding how bacterial communities respond to distillery wastewater discharge into rivers is crucial for restoring and maintaining aquatic ecosystem functions. However, feedback mechanisms involving bacterial generalists and specialists under distillery wastewater disturbance remain unexplored. Methods: This study employs high-throughput sequencing, neutral community models, and null models to analyze, for the first time, the distribution patterns, environmental adaptations, assembly processes, and driving factors of generalists and specialists upstream and downstream of a spirits wastewater discharge site in the Chishui River. Specialists exhibited more complex and compact co-occurrence networks than generalists, and specialist networks demonstrated greater stability. Differences in species formation rates, extinction rates, and diversification rates were observed between generalists and specialists across different river sections. Specialists exhibited stronger environmental adaptability than generalists under high disturbances from spirits wastewater, whereas generalists showed greater resilience under low disturbance conditions. Stochastic processes dominated community assembly, contributing more significantly to the formation of generalists than specialists. Conclusion: Our findings enhance the understanding of bacterial responses to spirits wastewater and provide valuable insights for the ecological restoration of polluted rivers.