Effects of turbulence on bacterial growth mediated through food web interactions
Effects of turbulence on bacterial growth mediated through food web interactions
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DOI：
10.3354/meps172293
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发表时间：
1998-10
影响因子：
2.5
通讯作者：
Francesc Peters;C. Marrasé;J. Gasol;M. Sala;L. Arin
中科院分区：
文献类型：
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作者：
Francesc Peters;C. Marrasé;J. Gasol;M. Sala;L. Arin
我们对地中海西北部的天然海水群落进行了实验室实验，以测试湍流是否会影响细菌的丰度和活动。当细菌与微生物群落的其余部分分离时，湍流对细菌没有直接影响。在微生物群落存在的情况下，细菌在湍流中比在静水中表现出更高的活性，并在更长的时间内保持高丰度。因此，湍流充分改变了水样中间接影响细菌的一些微生物成分或过程。细菌和色素真核生物的种群动态表明，在湍流条件下，群落的放牧从较小的猎物向较大的猎物转变。这种转变可以用原生动物捕食者的优势来解释，当与这些细胞的相遇率通过湍流下的剪切而增加时，原生动物捕食者能够捕食更大、更有营养的细胞。其结果是对浮游植物的更好控制和对细菌的放松。因此。沿海系统中偶发的高湍流事件可能加速营养物质的循环。
We performed laboratory experiments with natural seawater communities of the Northwestern Mediterranean to test whether turbulence could affect bacterial abundance and activity. There was no direct effect of turbulence on bacteria when they were uncoupled from the remainder of the microbial community. In the presence of the microbial community, bacteria showed higher activity and maintained high abundances for a longer time under turbulence than in still water Thus, turbulence sufficiently altered some microbial component or process in the water samples that indirectly affected bacteria. The population dynamics of bacteria and pigmented eukaryotes suggests that, under turbulence, there is a community grazing shift from smaller to larger prey sizes. This shift can be explained in terms of the advantage to protozoan predators which are able to prey on larger and more nutritious cells when the encounter rates with these cells are increased through the shear present under turbulence. The result is a higher control on phytoplankton and a relaxation of grazing on bacteria. Hence. episodic high turbulence events in coastal systems could accelerate nutrient recycling.