Screening and characterization of biological ice nuclei and their influence on the ice nucleation activity of soil and mineral dust.

微生物在土壤、隐形覆盖物和大气中无处不在。一些细菌、真菌、地衣和花粉物种已被确定为冰核粒子(INP)，它们可以在相对较高的温度下启动冰的形成，而土壤灰尘中的生物残留物是大气INP的潜在强大来源。然而，从植物、土壤和隐配子体覆盖层产生和释放的生物INP的来源尚不清楚，尽管它们在引发冰川和降水方面的潜在作用最近得到了支持。最近对不同土壤和空气样本的研究表明，来自多个门的不同冰核(IN)真菌不仅存在于空气和土壤中，而且可能是可栽培群落的丰富组成部分。因此，拟议的项目旨在从土壤、植物和隐形盖层中鉴定未知的IN微生物和物质，并调查它们对土壤粉尘IN活性的影响。我们实验室已经具备了对蓝藻等多种培养物进行筛选的必要技术。在拟议的项目中，还应在分子水平上表征新确定的IN生物体的INP。

Microorganisms are ubiquitous in soil, cryptogamic covers, and in the atmosphere. Several bacterial, fungal, lichen, and pollen species have been identified as ice nucleating particles (INP) that can initiate the formation of ice at relatively high temperatures and biological residues in soil dust are a potentially strong source of atmospheric INP. However, the sources of biological INP produced and released from plants, soil and cryptogamic covers remain unclear, even though their potential role in triggering glaciation and precipitation has recently been supported. Recent studies of various soil and air samples indicate that diverse ice nucleating (IN) fungi from more than one phylum are not only present in air and soil but can also be abundant components of the cultivable community. Thus, the proposed project is aimed at identifying unknown IN microorganisms and materials from soils, plants, and cryptogamic covers and on the investigation of their influence on the IN activity of soil dust. The necessary techniques for a screening of multiple cultures of e.g. cyanobacteria are well established in our laboratory. In the proposed project the INP of the new identified IN organisms should also be characterized on a molecular level.