Lake microbiome composition determines community adaptability to warming perturbations

Microbial communities are crucial for ecosystems. A central goal of microbial ecological research is to simplify the biodiversity in natural environments and quantify the functional roles to explore how the ecosystems respond under different environmental conditions. However, the research on the stability and dynamics of lake microbes in response to repeated warming stress is limited. To exclude confounding environmental factors, we conducted a 20-day repeated warming simulation experiment to examine the composition and function dynamics of lake microbial communities. Experimental warming significantly altered the community structure of bacteria instead of fungi. Microbial community structure, together with microbial biomass, jointly regulated the function of microbial communities. The plummeting of aerobic denitrifiers Pseudomonadaceae decreased by 99% (P < 0.001) after high temperature, leading to reduced microbial nitrogen metabolism on nitrogen respiration and nitrate respiration. Under warming conditions, the microbial community with higher adaptability showed more positive correlations and less competitive relationships in co-occurrence networks to acclimate to warming. Microbiome composition controlled carbon and nitrogen metabolism, thus determining lake microbial communities’ adaptability to heat stress. This study extended our insights on the lake microbial community response and adaptability under warming drivers.