Variable phosphorus uptake rates and allocation across microbial groups in the oligotrophic Gulf of Mexico: Variable microbial phosphorus uptake rate and allocation
Variable phosphorus uptake rates and allocation across microbial groups in the oligotrophic Gulf of Mexico: Variable microbial phosphorus uptake rate and allocation
复制标题
贫营养墨西哥湾微生物群体的可变磷吸收率和分配：可变微生物磷吸收率和分配
DOI：
10.1111/1462-2920.12932
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发表时间：
2015
影响因子：
5.1
通讯作者：
Duhamel, Solange
中科院分区：
文献类型：
--
作者：
Popendorf, Kimberly J.;Duhamel, Solange
微生物对溶解磷（P）的吸收是控制微生物生产和海洋P的命运和循环的重要杠杆。我们通过测量单个微生物群体（异养细菌和浮游植物群体Synechococcus，Prochlorococcus和picoeukaryotic phytoplankton）的P吸收速率来研究异养细菌和浮游植物在P循环中的相对作用。磷摄取率测定使用孵育与放射性标记的磷酸盐和腺苷三磷酸细胞分选流式细胞术耦合。我们发现，异养细菌是占主导地位的消费者的P生物量的基础上，人口的基础上。生物体积标准化的异养细菌每细胞的磷吸收速率（阿莫尔m− 3 h −1）大约比浮游植物的吸收速率大一个数量级，而异养细菌通常占总超微型浮游生物磷吸收的50%以上。我们假设，这种吸收率的变化反映了细胞磷分配策略的变化，并发现，事实上，利用磷脂生产的细胞磷吸收的分数显着高于异养细菌相比，蓝藻浮游植物。这些发现表明，异养细菌具有独特的P-导向生理学，并在溶解P循环中发挥主导作用。
Microbial uptake of dissolved phosphorus (P) is an important lever in controlling both microbial production and the fate and cycling of marine P. We investigated the relative role of heterotrophic bacteria and phytoplankton in P cycling by measuring the P uptake rates of individual microbial groups (heterotrophic bacteria and the phytoplankton groupsSynechococcus,Prochlorococcusand picoeukaryotic phytoplankton) in the P‐depleted Gulf of Mexico. Phosphorus uptake rates were measured using incubations with radiolabelled phosphate and adenosine triphosphate coupled with cell sorting flow cytometry. We found that heterotrophic bacteria were the dominant consumers of P on both a biomass basis and a population basis. Biovolume normalized heterotrophic bacteria P uptake rate per cell (amol P μm−3h−1) was roughly an order of magnitude greater than phytoplankton uptake rates, and heterotrophic bacteria were responsible for generally greater than 50% of total picoplankton P uptake. We hypothesized that this variation in uptake rates reflects variation in cellular P allocation strategies, and found that, indeed, the fraction of cellular P uptake utilized for phospholipid production was significantly higher in heterotrophic bacteria compared with cyanobacterial phytoplankton. These findings indicate that heterotrophic bacteria have a uniquely P‐oriented physiology and play a dominant role in cycling dissolved P.