Suspendable macromolecules are responsible for ice nucleation activity of birch and conifer pollen
Suspendable macromolecules are responsible for ice nucleation activity of birch and conifer pollen
复制标题
DOI：
10.5194/acp-12-2541-2012
复制
发表时间：
2012-01-01
影响因子：
6.3
通讯作者：
Grothe, H.
中科院分区：
文献类型：
--
作者：
Pummer, B. G.;Bauer, H.;Grothe, H.
生物气溶胶（细菌、花粉、孢子等）的冰核作用是一个越来越感兴趣的话题，因为它们对冰云形成的影响，从而对辐射强迫，全球气候的一个重要参数，尚未完全了解。在这里，我们表明，不同物种的花粉在其冰成核行为强烈不同。在实验室实验中，平均冻结温度范围为240 - 255 K。由于最有效的核（银，苏格兰松和常见的杜松花粉）的分布区域高达北方林线，它们的冰核活性可能是一种防冻机制。更有趣的是，已经证明，与花粉接触，然后与身体分离的水，与花粉粒本身一样好地成核。冰核必须是位于花粉上的易悬浮的大分子。一旦被提取出来，它们可以比重花粉粒在大气中分布得更远，因此可以推测，即使在对流层上部，花粉对冰云形成的影响也会增加。我们的实验得出的结论是，花粉冰核，与细菌和真菌的冰成核蛋白，是非蛋白质化合物。
The ice nucleation of bioaerosols (bacteria, pollen, spores, etc.) is a topic of growing interest, since their impact on ice cloud formation and thus on radiative forcing, an important parameter in global climate, is not yet fully understood. Here we show that pollen of different species strongly differ in their ice nucleation behaviour. The average freezing temperatures in laboratory experiments range from 240 to 255 K. As the most efficient nuclei (silver birch, Scots pine and common juniper pollen) have a distribution area up to the Northern timberline, their ice nucleation activity might be a cryoprotective mechanism. Far more intriguingly, it has turned out that water, which has been in contact with pollen and then been separated from the bodies, nucleates as good as the pollen grains themselves. The ice nuclei have to be easily-suspendable macromolecules located on the pollen. Once extracted, they can be distributed further through the atmosphere than the heavy pollen grains and so presumably augment the impact of pollen on ice cloud formation even in the upper troposphere. Our experiments lead to the conclusion that pollen ice nuclei, in contrast to bacterial and fungal ice nucleating proteins, are non-proteinaceous compounds.