2026年8月26日，瑞士苏黎世联邦理工学院分子系统生物学研究所Uwe Sauer等科学家在《自然》发表研究，揭示了海洋中岩藻聚糖通过功能互补的细菌群协同降解的机制。

岩藻聚糖是一类由褐藻和硅藻产生的复杂多糖，由于其抵抗微生物降解的能力，对长期碳封存具有贡献。尽管单个微生物可以分解这些多糖的一部分，但完全分解在自然界中是否可能发生，以及如果可能，通过何种机制实现，仍不清楚。在此，研究人员表明，岩藻聚糖通过具有互补代谢功能的特化细菌之间的协同相互作用被降解。通过对一个重构的海洋联合体的代谢组学分析，研究人员揭示了细菌的代谢功能群，它们分别优先降解硫酸化岩藻糖骨架或稀有单糖的侧枝。这种功能分工导致了不同降解菌之间数量出乎意料多的协同相互作用，将降解效率提高了高达97.1%。尽管不同藻类来源的岩藻聚糖结构各异，但降解菌的代谢功能保持一致，从而能够基于群落和底物组成定量预测降解结果。功能互补的岩藻聚糖降解菌在海洋宏基因组中频繁共现，表明协同降解是一种全球相关的策略。研究人员的发现表明，复杂生物聚合物的环境周转不仅取决于降解菌个体的代谢能力，还取决于由底物结构塑造的生态相互作用。这项工作为理解海洋碳循环以及工程化合成微生物联合体以降解顽固多糖提供了机制框架。岩藻聚糖的高效降解依赖于功能互补的细菌群，它们协同分解骨架糖和侧链糖，揭示了一个保守的、全球相关的塑造海洋碳循环的机制。

附：英文原文

Title: Synergistic degradation of fucoidans in the ocean

Author: Sichert, Andreas, Pollak, Shaul, Priest, Taylor, Goyal, Akshit, Miravet-Verde, Samuel, Sunagawa, Shinichi, Cordero, Otto X., Sauer, Uwe

Issue&Volume: 2026-08-26

Abstract: Fucoidans, a class of complex polysaccharides produced by brown algae and diatoms, contribute to long-term carbon sequestration owing to their resistance to microbial degradation. Although individual microorganisms can break down portions of these polysaccharides, it remains unclear whether complete breakdown is possible in nature and, if so, by what mechanisms. Here we show that fucoidans are degraded through synergistic interactions between specialized bacteria with complementary metabolic functions. Using metabolomic analysis of a reconstructed marine consortium, we uncovered metabolic guilds of bacteria that preferentially degrade either the sulfated fucose backbone or the side branches of rare monomers. This functional division of labour leads to an unexpectedly high number of synergistic interactions between different degraders that enhanced degradation efficiency up to 97.1%. Despite varying fucoidan structures across different types of algae, the metabolic functions of degraders remained conserved, enabling quantitative prediction of degradation outcomes based on community and substrate composition. The frequent co-occurrence of functionally complementary fucoidan degraders in ocean metagenomes suggests that synergistic degradation is a globally relevant strategy. Our findings suggest that the environmental turnover of complex biopolymers depends not only on individual metabolic capabilities of degraders but also on ecological interactions shaped by substrate architecture. This work provides a mechanistic framework for understanding carbon cycling in the ocean and for engineering synthetic microbial consortia to degrade recalcitrant polysaccharides. Efficient degradation of fucoidans depends on complementary bacterial guilds that cooperatively break backbone and side-chain sugars, revealing a conserved, globally relevant mechanism that shapes marine carbon cycling.

DOI: 10.1038/s41586-026-10980-z

Source: https://www.nature.com/articles/s41586-026-10980-z