Seasonal dynamics of bacterial growth efficiencies in relation to phytoplankton in the southern North Sea
Seasonal dynamics of bacterial growth efficiencies in relation to phytoplankton in the southern North Sea
复制标题
北海南部细菌生长效率与浮游植物相关的季节动态
DOI：
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发表时间：
2005
期刊：
影响因子：
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通讯作者：
G. Herndl
中科院分区：
文献类型：
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作者：
Thomas Reinthaler;G. Herndl
摘要：异养浮游细菌在海洋碳循环中的主要功能是将溶解有机碳（DOC）转化为生物量和CO2。用细菌生长效率（BGE = BP/（BP + BR）×100）表示细菌生物量生产（BP）与呼吸（BR）的相对重要性。对天然DOC上生长的浮游细菌的BGE动态的研究覆盖了整个季节周期，目前还很少。我们在北海南部的一个季节性周期内测量了BP和BR，共150个站，以确定BGE的季节性变化。虽然BP变化超过1个数量级的季节性周期，BR变化只有2倍。细胞特异性BP与初级生产有关，而BR与初级生产无关。平均BGE从冬季的6 ± 3%增加到春季和夏季的25 ± 9%。深度集成BR是相当稳定的季节性周期，平均57%的颗粒初级生产。根据浮游细菌的呼吸作用和20%的年平均BGE，北海南部浮游细菌对有机碳的需求量占颗粒初级生产力的70%左右，表明原生有机物生产足以满足浮游细菌对有机碳的需求.关键词：浮游细菌·细菌生产力·细菌呼吸·细菌生长效率·初级生产力·北海
ABSTRACT: The main function of heterotrophic bacterioplankton in marine carbon cycling is theconversion of dissolved organic carbon (DOC) into biomass and CO 2 . The relative importance of bac-terial biomass production (BP) versus respiration (BR) is expressed by the bacterial growth efficiency(BGE = BP/(BP + BR) ×100). Studies on the dynamics of the BGE of bacterioplankton growing on nat-ural DOC covering entire seasonal cycles are scarce. We measured BP and BR over a seasonal cyclein the southern North Sea at a total of 150 stations to determine seasonal variability in BGE. While BPvaried over 1 order of magnitude over the seasonal cycle, BR varied only 2-fold. Cell-specific BP wasrelated to primary production while BR was not. Mean BGE increased from 6 ± 3% in the winter to25 ± 9% in the spring and summer. Depth-integrated BR was fairly stable over the seasonal cycle,averaging 57% of the particulate primary production. Based on the bacterioplankton respiration andthe mean annual BGE of 20%, bacterioplankton organic carbon demand amounts to ∼70% of theparticulate primary production in the southern North Sea, suggesting that autochthonous organicmatter production is sufficient to fuel bacterioplankton carbon demand.KEY WORDS: Bacterioplankton · Bacterial production · Bacterial respiration · Bacterial growthefficiency · Primary production · North Sea