Differential effects of microorganism-invertebrate interactions on benthic nitrogen cycling
Differential effects of microorganism-invertebrate interactions on benthic nitrogen cycling
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DOI：
10.1111/j.1574-6941.2012.01400.x
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发表时间：
2012-10-01
影响因子：
4.2
通讯作者：
Prosser, James I.
中科院分区：
文献类型：
--
作者：
Gilbertson, William W.;Solan, Martin;Prosser, James I.
动物体内的无脊椎动物活动可以从根本上改变沉积物中的物理化学条件并影响养分循环。然而，尽管无脊椎动物活动与硝化等微生物介导的过程之间存在明显的联系，但生物扰动大型动物影响微生物群落的机制却很少受到关注。这项研究为三种功能对比的大型动物物种（Hediste diversicolor、Corophium volutator、Hydrobia ulvae）对微生物氮转化的差异刺激提供了强有力的证据。尽管硝化作用增强，但沉积物-水界面处的氨氧化细菌（AOB）和氨氧化古菌（AOA）的丰度在大型动物群的存在下并没有显着变化。然而，大型动物活动的物种特异性差异确实影响了氨氧化器群落结构，在 C. volutator 或 H. ulvae 存在的情况下，相对于 AOA 增加了 AOB 丰度，但在 H. diversicolor 和无大型动物处理中没有变化。大型动物处理之间的变性梯度凝胶电泳图谱相似，但在 C. volutator 存在下，一条 AOB 条带的相对强度增加，在 H. diversicolor 处理中降低，在 H. ulvae 处理中没有变化。这些数据表明，大型生物扰动和养分循环之间的联系并不是通过表面沉积物中氨氧化剂丰度的变化来表达的，而是与取决于无脊椎动物物种的 AOA : AOB 比率的变化有关。
Infaunal invertebrate activity can fundamentally alter physicochemical conditions in sediments and influence nutrient cycling. However, despite clear links between invertebrate activity and microbially mediated processes such as nitrification, the mechanisms by which bioturbating macrofauna affect microbial communities have received little attention. This study provides strong evidence for differential stimulation of microbial nitrogen transformations by three functionally contrasting species of macrofauna (Hediste diversicolor, Corophium volutator, Hydrobia ulvae). Despite increased nitrification, abundance of ammonia-oxidising bacteria (AOB) and ammonia-oxidising archaea (AOA) at the sedimentwater interface did not significantly change in the presence of macrofauna. However, species-specific differences in macrofaunal activity did influence ammonia oxidiser community structure, increasing AOB abundance relative to AOA in the presence of C. volutator or H. ulvae, but with no change in H. diversicolor and no-macrofauna treatments. Denaturing gradient gel electrophoresis profiles were similar between macrofaunal treatments, although one AOB band increased in relative intensity in the presence of C. volutator, decreased in the H. diversicolor treatment and was unchanged in the H. ulvae treatment. These data suggest that links between bioturbating macrofauna and nutrient cycling are not expressed through changes in the abundance of ammonia oxidisers in surface sediments, but are associated with changes in the AOA : AOB ratio depending on the invertebrate species.