海洋氨氧化古菌合成维生素B12的生态意义

Ecological significance of vitamin B12 synthesis by ammonia-oxidizing archaea

摘要:

维生素B₁₂ (vitamin B₁₂, VB₁₂)是大部分生物的必需营养素和生长辅助因子，它不仅影响微生物群落结构和海洋初级生产力，还对全球生物地球化学循环过程也具有重要影响，被称为海洋生态系统中的“硬通货”。氨氧化古菌(ammonia-oxidizing archaea, AOA)首次在2005年从海洋中分离得到，具有化能自养的特点。基因组、代谢组和培养实验均表明，AOA是海洋中为数不多的具备生物合成VB₁₂能力的微生物类群，这对于维持微生物群落的稳定性和生物地球化学功能具有重要意义。本文综述了海洋中VB₁₂的测定方法、分布特征，以及AOA产生VB₁₂的途径特点，论述了AOA在海洋VB₁₂供应方面的重要性，并展望了海洋AOA产生VB₁₂研究的未来重点方向。

Abstract:

Vitamin B₁₂ (VB₁₂) is an essential nutrient and growth cofactor for the majority of organisms. It exerts influence not only on the structure of microbial communities and marine primary productivity but also on the global biogeochemical cycles, thus justifying its designation as a “hard currency” in marine ecosystems. Ammonia-oxidizing archaea (AOA), initially isolated from the ocean in 2005, are distinguished by their chemolithoautotrophic characteristics. Genomic, metabolomic, and culture studies have demonstrated that AOA are among the few microbial groups capable of synthesizing VB₁₂ in the ocean. This capability is crucial for maintaining microbial community stability and biogeochemical functions. This review summarizes the measurement methods and distribution characteristics of VB₁₂ in the ocean and the pathways through which AOA produce VB₁₂. It discusses the importance of AOA in marine VB₁₂ supply and outlines the future research directions for VB₁₂ production by AOA.