Wienhausen Gerrit, Moraru Cristina, Bruns Stefan, Tran Den Quoc, Sultana Sabiha, Wilkes Heinz, Dlugosch Leon, Azam Farooq, Simon Meinhard
Institute for Chemistry and Biology of the Marine Environment (ICBM), School of Mathematics and Science, Carl von Ossietzky Universität Oldenburg, Oldenburg, Germany.
Scripps Institution of Oceanography, Marine Biology Research Division, University of California San Diego, La Jolla, CA, USA.
Nature. 2024 May;629(8013):886-892. doi: 10.1038/s41586-024-07396-y. Epub 2024 May 8.
Cobalamin (vitamin B, herein referred to as B) is an essential cofactor for most marine prokaryotes and eukaryotes. Synthesized by a limited number of prokaryotes, its scarcity affects microbial interactions and community dynamics. Here we show that two bacterial B auxotrophs can salvage different B building blocks and cooperate to synthesize B. A Colwellia sp. synthesizes and releases the activated lower ligand α-ribazole, which is used by another B auxotroph, a Roseovarius sp., to produce the corrin ring and synthesize B. Release of B by Roseovarius sp. happens only in co-culture with Colwellia sp. and only coincidently with the induction of a prophage encoded in Roseovarius sp. Subsequent growth of Colwellia sp. in these conditions may be due to the provision of B by lysed cells of Roseovarius sp. Further evidence is required to support a causative role for prophage induction in the release of B. These complex microbial interactions of ligand cross-feeding and joint B biosynthesis seem to be widespread in marine pelagic ecosystems. In the western and northern tropical Atlantic Ocean, bacteria predicted to be capable of salvaging cobinamide and synthesizing only the activated lower ligand outnumber B producers. These findings add new players to our understanding of B supply to auxotrophic microorganisms in the ocean and possibly in other ecosystems.
钴胺素（维生素B，本文简称为B）是大多数海洋原核生物和真核生物必需的辅因子。由于只有少数原核生物能够合成钴胺素，其稀缺性影响着微生物间的相互作用和群落动态。在此，我们发现两种细菌钴胺素营养缺陷型能够挽救不同的钴胺素组成成分，并合作合成钴胺素。一种科尔韦氏菌属（Colwellia sp.）细菌合成并释放出活化的低级配体α-核黄素，另一种钴胺素营养缺陷型细菌——玫瑰色杆菌属（Roseovarius sp.）细菌利用该配体生成咕啉环并合成钴胺素。玫瑰色杆菌属细菌只有在与科尔韦氏菌属细菌共培养时，且仅在诱导出玫瑰色杆菌属细菌中编码的原噬菌体时才会释放钴胺素。在这些条件下，科尔韦氏菌属细菌随后的生长可能是由于玫瑰色杆菌属细菌裂解细胞提供了钴胺素。需要更多证据来支持原噬菌体诱导在钴胺素释放过程中的因果作用。这种配体交叉喂养和联合钴胺素生物合成的复杂微生物相互作用似乎在海洋浮游生态系统中广泛存在。在热带大西洋西部和北部，预计能够挽救钴胺酰胺并仅合成活化低级配体的细菌数量超过了钴胺素生产者。这些发现为我们理解海洋乃至其他生态系统中营养缺陷型微生物的钴胺素供应增加了新的因素。
