Shotgun metagenomics of tropical stream sediments
This study examines how anthropogenic degradation affects sediment microbiomes in tropical headwater streams. Using shotgun metagenomics, the authors compare preserved and degraded environments and show that, although overall diversity remains unchanged, microbial composition and functional profiles shift substantially. Degraded sites are characterized by microorganisms associated with nutrient-rich conditions and anaerobic processes, whereas preserved streams favor taxa adapted to low-nutrient environments and oxidative metabolisms. Additionally, degradation is linked to an increased potential for greenhouse gas emissions and a higher abundance of antibiotic resistance genes. Overall, the findings indicate that human pressure profoundly alters the ecological functioning of these ecosystems, reshaping their biogeochemical roles and sanitary relevance.