Elucidation of catabolic processes of chlorophylls in marine and lacustrine environments

叶绿素是光合作用必不可少的生物分子，但也具有光毒性，可以产生单线态氧，这是一种对生物体具有剧毒的活性氧。目前的研究表明，水生原生生物以微藻为食，将叶绿素降解为解毒分解产物“环烯醇”。这种环烯醇分解代谢在不同的原生生物群体中是常见的，并且在任何水生环境中都普遍存在，这表明这些原生生物在水生物质和能量流动中做出了重要贡献。分解代谢对藻类的内共生进化过程也起着至关重要的作用。

Chlorophylls are essential biomolecules for photosynthesis yet also phototoxic to generate singlet oxygen, a highly toxic reactive oxygen for organisms. The present research elucidated that aquatic protists feeding on microalgae degradate chlorophylls into detoxified catabolites “cyclo-enols”. This cyclo-enol catabolism is common among diverse groups of protists and also ubiquitously generated in any aquatic environments, suggesting significant contributions of such protists in aquatic material and energy flows. The catabolism has also been critical for the endosymbiotic evolutionary processes of algae.