Microbial mediators of environmental change in the Yellow River basin: Flavobacterium and pollution dynamics during...

The Yellow River basin, densely populated and characterized by intensive industrial and agricultural activities, faces significant water quality concerns. However, the impact of different pollution sources (e.g., industrial, domestic, and mixed wastewater) on the microbial spectrum in sections of the Yellow River during the dry season remains unclear. This research seeks to address this knowledge gap by examining the variations of microbial community structure and ecology influenced by different pollution sources. Our results showed that pH, NO₃-N, TP and turbidity differed significantly among the different pollution groups. Industrial pollution increased species richness, while domestic wastewater reduced microbial diversity. Flavobacterium abundance increased significantly with domestic pollution but decreased dramatically with industrial pollution. Specific genera linked to domestic pollution included Pseudarcicella and Denitratisoma, while industrial pollution was associated with Sulfurimonas Trichococcus, Halomonas, and fungal genera such as Fusarium. Network analysis revealed the pollutants disrupted the community structure and dissolved symbiotic interactions, thereby promoting the emergence of new dominant microorganisms. KEGG analysis found that domestic sources were associated with amino acid metabolism and secondary metabolite biosynthesis, while industrial sources enhanced activity in isoflavonoid biosynthesis and carbohydrate metabolism. Our findings provide a comprehensive microbial ecological analysis of the sediment-rich core industrial area of the Yellow River, shedding light on the impacts of different pollution sources and river section locations on microbial networks, offering valuable insights for ecological safety and protection.