Control of microbial communities by the macrofauna: a sensitive interaction in the context of extreme summer temperatures?
Control of microbial communities by the macrofauna: a sensitive interaction in the context of extreme summer temperatures?
复制标题
大型动物对微生物群落的控制：夏季极端温度下的敏感相互作用？
DOI：
10.1007/s00442-006-0544-7
复制
发表时间：
2007
期刊：
影响因子：
2.7
通讯作者：
M. Weitere
中科院分区：
文献类型：
--
作者：
Carsten Viergutz;M. Kathol;H. Norf;H. Arndt;M. Weitere
气候模型预测，在不久的将来，北方夏季极端炎热事件的频率将越来越高。我们假设，微生物放牧的后生动物大型底栖动物是一种相互作用，变得不平衡，在高温下，由于不同的发展的后生动物的放牧率和微生物群落的增长率随着温度的升高。为了验证这一假设，我们进行了放牧实验中，我们测量的影响，温度升高的发展的放牧率的河蚌的增长率的单细胞猎物社区（一个自然的异养鞭毛虫社区从一条大河）。在第一个实验系列中，使用河蚬作为食草动物，并在添加碳源（酵母提取物）的情况下，当温度从19 ° C增加到25°C以上时，猎物的生长速率的增加比捕食者的食草速率的增加要强得多。这也是贻贝适应温暖温度的结果。此后，在25 ° C和30°C的温度下用天然河水进行具体实验。同样，随着温度的升高，两种贻贝（C。fluminea和Dreissena polymorpha）。当使用底栖微生物捕食者群落（以纤毛虫为主的生物膜）代替底栖贻贝进行相同的实验时，可以观察到放牧率相对于随温度的生长率的增加。我们的数据表明，在中等温度下平衡的捕食者-猎物相互作用（后生动物和微生物之间）在高温下可能变得不平衡。这可能对微生物群落的结构和功能产生重大影响，因为预计夏季热浪的频率会增加。
Climate models predict an increasing frequency of extremely hot summer events in the northern hemisphere for the near future. We hypothesised that microbial grazing by the metazoan macrofauna is an interaction that becomes unbalanced at high temperatures due to the different development of the grazing rates of the metazoans and the growth rates of the microbial community with increasing temperature. In order to test this hypothesis, we performed grazing experiments in which we measured the impact of increasing temperatures on the development of the grazing rates of riverine mussels in relation to the growth rates of a unicellular prey community (a natural heterotrophic flagellate community from a large river). In a first experimental series using Corbicula fluminea as a grazer and under the addition of a carbon source (yeast extract), the increase of the prey’s growth rates was considerably stronger than that of the predator’s grazing rates when temperatures were increased from 19 to over 25°C. This was also the outcome when the mussels had been acclimatized to warm temperatures. Hereafter, specific experiments with natural river water at temperatures of 25 and 30°C were performed. Again, a strong decrease of the mussels’ grazing rates in relation to the flagellate growth rates with increasing temperature occurred for two mussel species (C. fluminea and Dreissena polymorpha). When performing the same experiment using a benthic microbial predator community (biofilms dominated by ciliates) instead of the benthic mussels, an increase of the grazing rates relative to the growth rates with temperature could be observed. Our data suggest that predator–prey interactions (between metazoans and microbes) that are balanced at moderate temperatures could become unbalanced at high temperatures. This could have significant effects on the structure and function of microbial communities in light of the predicted increasing frequency of summer heat waves.