德国奥尔登堡卡尔冯奥西茨基大学Meinhard Simon和Gerrit Wienhausen共同合作，近期取得重要工作进展。他们研究提出，配体交互共生可解决细菌维生素B₁₂的缺乏症。相关研究成果2024年5月8日在线发表于《自然》杂志上。

据介绍，钴胺素（维生素B₁₂，此处简称B₁₂）是大多数海洋原核生物和真核生物的必需辅因子。由数量有限的原核生物合成，其稀缺性影响微生物的相互作用和群落动力学。

研究人员发现两种细菌B12营养缺陷型生物可以挽救不同的B₁₂构建块，并协同合成B₁₂。Colwellia sp.合成并释放活化的低配体α-ribazole，该配体被另一种B12营养缺陷型生物Roseovarius sp.用于产生corrin环并合成B₁₂。Roseovarius sp.释放B₁₂仅发生在与Colwelia sp.共培养的情况下，并且仅在Roseovarius sp.编码的噬菌体被诱导时才会发生。Colwelia sp.在这些条件下的后续生长可能是由于Roseovarius sp.裂解的细胞提供了B₁₂。

需要进一步的证据来支持原噬菌体诱导在B₁₂释放中的致病作用。配体交叉喂养和联合生物合成B₁₂的这些复杂的微生物相互作用似乎在海洋远洋生态系统中广泛存在。在热带大西洋西部和北部，预计能够回收钴酰胺并仅合成活化的低配体的细菌数量超过了B₁₂生产者数量。

总之，这些发现为人们理解海洋中以及可能的其他生态系统中营养缺陷型微生物的B12供应增加了新的参与者。

附：英文原文

Title: Ligand cross-feeding resolves bacterial vitamin B12 auxotrophies

Author: Wienhausen, Gerrit, Moraru, Cristina, Bruns, Stefan, Tran, Den Quoc, Sultana, Sabiha, Wilkes, Heinz, Dlugosch, Leon, Azam, Farooq, Simon, Meinhard

Issue&Volume: 2024-05-08

Abstract: Cobalamin (vitamin B12, herein referred to as B12) is an essential cofactor for most marine prokaryotes and eukaryotes1,2. Synthesized by a limited number of prokaryotes, its scarcity affects microbial interactions and community dynamics2,3,4. Here we show that two bacterial B12 auxotrophs can salvage different B12 building blocks and cooperate to synthesize B12. A Colwellia sp. synthesizes and releases the activated lower ligand α-ribazole, which is used by another B12 auxotroph, a Roseovarius sp., to produce the corrin ring and synthesize B12. Release of B12 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 B12 by lysed cells of Roseovarius sp. Further evidence is required to support a causative role for prophage induction in the release of B12. These complex microbial interactions of ligand cross-feeding and joint B12 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 B12 producers. These findings add new players to our understanding of B12 supply to auxotrophic microorganisms in the ocean and possibly in other ecosystems.

DOI: 10.1038/s41586-024-07396-y

Source: https://www.nature.com/articles/s41586-024-07396-y