Key Laboratory of Coastal Environment and Resources of Zhejiang Province, School of Engineering, Westlake University, 18 Shilongshan Road, Hangzhou 310024, China; Institute of Advanced Technology, Westlake Institute for Advanced Study, 18 Shilongshan Road, Hangzhou 310024, China.
Key Laboratory of Coastal Environment and Resources of Zhejiang Province, School of Engineering, Westlake University, 18 Shilongshan Road, Hangzhou 310024, China; Institute of Advanced Technology, Westlake Institute for Advanced Study, 18 Shilongshan Road, Hangzhou 310024, China; Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, China.
Water Res. 2022 Jul 15;220:118674. doi: 10.1016/j.watres.2022.118674. Epub 2022 May 25.
Cyanobacterial harmful algal blooms (CyanoHABs) are globally intensifying and exacerbated by climate change and eutrophication. However, microbiota assembly mechanisms underlying CyanoHABs remain elusive. Especially, cyanopeptides, as a group of bioactive secondary metabolites of cyanobacteria, could affect microbiota assembly and ecosystem function. Here, the trajectory of cyanopeptides was followed and linked to microbiota during Microcystis-dominated CyanoHABs in Lake Taihu, China. The most abundant cyanopeptide classes detected included microginin, spumigin, microcystin, nodularin and cyanopeptolin with total MC-LR-equivalent concentrations between 0.23 and 2051.54 ppb, of which cyanotoxins beyond microcystins (e.g., cyanostatin B and nodularin_R) far exceeded reported organismal IC and negatively correlated with microbiota diversity, exerting potential collective eco-toxicities stronger than microcystins alone. The microbial communities were differentiated by size fraction and sampling date throughout CyanoHABs, and surprisingly, their variances were better explained by cyanopeptides (19-38%) than nutrients (0-16%). Cyanopeptides restriction (e.g., inhibition) and degradation were first quantitatively verified as the deterministic drivers governing community assembly, with stochastic processes being associated with the interplay between cyanopeptide dynamics and lake microbiota. This study presents an emerging paradigm in which cyanopeptides restriction and degradation co-mediate lake water microbiota assembly, unveiling new insights into the ecotoxicological significance of CyanoHABs to freshwater ecosystems.
蓝藻有害藻华（CyanoHABs）在全球范围内加剧，并受到气候变化和富营养化的加剧。然而，CyanoHABs 下的微生物组组装机制仍然难以捉摸。特别是，作为蓝藻生物活性次生代谢物的一组氰肽，可以影响微生物组的组装和生态系统功能。在这里，跟踪了中国太湖蓝藻为主的 CyanoHABs 中氰肽的轨迹，并将其与微生物组联系起来。检测到的最丰富的氰肽类包括微囊藻素、海绵肽、微囊藻毒素、节球藻毒素和氰肽菌素，总 MC-LR 当量浓度在 0.23 到 2051.54 ppb 之间，其中超出微囊藻毒素的蓝藻毒素（例如，蓝藻抑素 B 和节球藻毒素_R）远远超过报道的生物体 IC，并与微生物组多样性呈负相关，产生的潜在集体生态毒性强于单独的微囊藻毒素。微生物群落通过大小分数和采样日期在 CyanoHABs 期间进行了区分，令人惊讶的是，它们的方差通过氰肽（19-38%）比养分（0-16%）更好地解释。首次定量验证了氰肽的限制（例如抑制）和降解作为决定群落组装的确定性驱动因素，随机过程与氰肽动力学和湖泊微生物组之间的相互作用有关。这项研究提出了一个新兴的范例，即氰肽的限制和降解共同介导了湖泊水微生物组的组装，揭示了 CyanoHABs 对淡水生态系统的生态毒理学意义的新见解。
