PDF(Pubmed)
Abstract：
Vitamin B1 (thiamin) is a vital nutrient for most cells in nature, including marine plankton. Early and recent experiments show that B1 degradation products instead of B1 can support the growth of marine bacterioplankton and phytoplankton. However, the use and occurrence of some degradation products remains uninvestigated, namely N-formyl-4-amino-5-aminomethyl-2-methylpyrimidine (FAMP), which has been a focus of plant oxidative stress research. We investigated the relevance of FAMP in the ocean. Experiments and global ocean meta-omic data indicate that eukaryotic phytoplankton, including picoeukaryotes and harmful algal bloom species, use FAMP while bacterioplankton appear more likely to use deformylated FAMP, 4-amino-5-aminomethyl-2-methylpyrimidine. Measurements of FAMP in seawater and biomass revealed that it occurs at picomolar concentrations in the surface ocean, heterotrophic bacterial cultures produce FAMP in the dark-indicating non-photodegradation of B1 by cells, and B1-requiring (auxotrophic) picoeukaryotic phytoplankton produce intracellular FAMP. Our results require an expansion of thinking about vitamin degradation in the sea, but also the marine B1 cycle where it is now crucial to consider a new B1-related compound pool (FAMP), as well as generation (dark degradation-likely via oxidation), turnover (plankton uptake), and exchange of the compound within the networks of plankton. IMPORTANCE Results of this collaborative study newly show that a vitamin B1 degradation product, N-formyl-4-amino-5-aminomethyl-2-methylpyrimidine (FAMP), can be used by diverse marine microbes (bacteria and phytoplankton) to meet their vitamin B1 demands instead of B1 and that FAMP occurs in the surface ocean. FAMP has not yet been accounted for in the ocean and its use likely enables cells to avoid B1 growth deficiency. Additionally, we show FAMP is formed in and out of cells without solar irradiance-a commonly considered route of vitamin degradation in the sea and nature. Altogether, the results expand thinking about oceanic vitamin degradation, but also the marine B1 cycle where it is now crucial to consider a new B1-related compound pool (FAMP), as well as its generation (dark degradation-likely via oxidation), turnover (plankton uptake), and exchange within networks of plankton.
摘要：
维生素B1（硫胺素）是自然界中大多数细胞的重要营养素，包括海洋浮游生物.早期和最近的实验表明，B1降解产物代替B1可以支持海洋浮游细菌和浮游植物的生长。然而,一些降解产物的使用和发生仍未调查，即N-甲酰基-4-氨基-5-氨基甲基-2-甲基嘧啶（FAMP），一直是植物氧化应激研究的热点。我们调查了FAMP在海洋中的相关性。实验和全球海洋基因组数据表明，真核浮游植物，包括真核生物和有害的藻类水华物种，使用FAMP，而浮游细菌似乎更有可能使用变形FAMP，4-氨基-5-氨基甲基-2-甲基嘧啶。对海水和生物量中的FAMP的测量表明，它发生在表层海洋中的皮摩尔浓度下，异养细菌培养物在细胞对B1的黑暗指示非光降解中产生FAMP，需要B1的（营养缺陷型）微微真核浮游植物产生细胞内FAMP。我们的结果需要扩大对海洋中维生素降解的思考，还有海洋B1循环，现在考虑新的B1相关复合池（FAMP）至关重要，以及生成（黑暗降解-可能通过氧化），营业额(浮游生物吸收)，以及浮游生物网络内化合物的交换。重要性这项合作研究的结果表明，维生素B1降解产物，N-甲酰基-4-氨基-5-氨基甲基-2-甲基嘧啶(FAMP),可以被各种海洋微生物（细菌和浮游植物）用来满足其维生素B1而不是B1的需求，并且FAMP发生在表层海洋中。FAMP尚未在海洋中得到解释，它的使用可能使细胞避免B1生长不足。此外,我们表明，FAMP是在没有太阳辐射的情况下在细胞内外形成的，这是海洋和自然界中维生素降解的一种通常被认为的途径。总之,结果扩展了人们对海洋维生素降解的思考，还有海洋B1循环，现在考虑新的B1相关复合池（FAMP）至关重要，以及它的产生（黑暗降解-可能通过氧化），营业额(浮游生物吸收)，和浮游生物网络内的交换。
