The co-occurrence of cyanobacterial harmful algal blooms and contaminants is an increasing environmental concern in freshwater worldwide. Our field investigations coupled with laboratory incubations demonstrated that the microbial degradation potential of 17β-estradiol (E2) with estrone as the intermediate was primarily driven by increased dissolved organic matter (DOM) in the water column of a cyanobacterial bloom. To explain the intrinsic contribution of cyanobacterial-derived DOM (C-DOM) to estrogen biodegradation, a combination of methods including bioassay, ultrahigh-resolution mass spectrometry, and microbial ecology were applied. The results showed that preferential assimilation of highly biodegradable structures, including protein-, carbohydrate-, and unsaturated hydrocarbon-like molecules sustained bacterial growth, selected for more diverse microbes, and resulted in greater estrogen biodegradation compared to less biodegradable molecules (lignin- and tannin-like molecules). The biodegradability of C-DOM decreased from 78% to 1%, whereas the E2 biodegradation rate decreased dramatically at first, then increased with the accumulation of recalcitrant, bio-produced lipid-like molecules in C-DOM. This change was linked to alternative substrate-induced selection of the bacterial community under highly refractory conditions, as suggested by the greater biomass-normalized E2 biodegradation rate after a 24-h lag phase. In addition to the increased frequency of potential degraders, such as Sphingobacterium, the network analysis revealed that C-DOM molecules distributed in high H/C (protein- and lipid-like molecules) were the main drivers structuring the bacterial community, inducing strong deterministic selection of the community assemblage and upregulating the metabolic capacity for contaminants. These findings provide strong evidence that estrogen biodegradation in eutrophic water may be facilitated by cyanobacterial blooms and provide a theoretical basis for ecological remediation of estrogen pollution.

蓝藻有害藻华和污染物的同时发生是全球淡水中日益严重的环境问题。我们的实地调查和实验室孵化表明，以雌酮为中间体的 17β-雌二醇 (E2) 的微生物降解潜力主要是由蓝藻水华水柱中溶解有机物 (DOM) 的增加驱动的。为了解释蓝藻衍生的 DOM (C-DOM) 对雌激素生物降解的内在贡献，应用了包括生物测定、超高分辨率质谱和微生物生态学在内的方法的组合。结果表明，优先同化高度可生物降解的结构，包括蛋白质、碳水化合物和不饱和烃类分子，可维持细菌的生长，选择用于更多样化的微生物，并且与生物降解性较差的分子（木质素和单宁样分子）相比，雌激素的生物降解性更强。C-DOM 的生物降解能力从 78% 下降到 1%，而 E2 的生物降解率首先急剧下降，然后随着顽固的生物产生的类脂分子在 C-DOM 中的积累而增加。这种变化与在高度难处理的条件下细菌群落的替代底物诱导选择有关，正如在 24 小时滞后期后更高的生物量归一化 E2 生物降解率所表明的那样。除了潜在降解物的频率增加之外，例如 C-DOM 的生物降解能力从 78% 下降到 1%，而 E2 的生物降解率首先急剧下降，然后随着顽固的生物产生的类脂分子在 C-DOM 中的积累而增加。这种变化与在高度难处理的条件下细菌群落的替代底物诱导选择有关，正如在 24 小时滞后期后更高的生物量归一化 E2 生物降解率所表明的那样。除了潜在降解物的频率增加之外，例如 C-DOM 的生物降解能力从 78% 下降到 1%，而 E2 的生物降解率首先急剧下降，然后随着顽固的生物产生的类脂分子在 C-DOM 中的积累而增加。这种变化与在高度难处理的条件下细菌群落的替代底物诱导选择有关，正如在 24 小时滞后期后更高的生物量归一化 E2 生物降解率所表明的那样。除了潜在降解物的频率增加之外，例如 正如在 24 小时滞后期后更高的生物量归一化 E2 生物降解率所表明的那样。除了潜在降解物的频率增加之外，例如 正如在 24 小时滞后期后更高的生物量归一化 E2 生物降解率所表明的那样。除了潜在降解物的频率增加之外，例如鞘氨醇，网络分析表明，分布在高 H/C（蛋白质和类脂分子）中的 C-DOM 分子是构建细菌群落的主要驱动力，诱导群落组合的强确定性选择并上调污染物的代谢能力. 这些发现为富营养水中雌激素的生物降解提供了强有力的证据，蓝藻大量繁殖可能促进了雌激素的生物降解，并为雌激素污染的生态修复提供了理论基础。