Biodiversität und DNA-Taxonomie von Algen und Cyanobakterien in kalzifizierenden Biofilmen

验证和进一步阐明叠层石形成过程中蓝藻和微藻的分类特异性活动是本项目的主要目标。在前一个项目阶段，关键球员蓝藻和硅藻从两个示范石灰华小溪被发现，现在需要探索他们的原位丰度和分布模式的关系碳酸钙沉淀和碳酸钙-无区域。这将通过rRNA靶向荧光原位杂交来可视化。主要参与者蓝藻和藻类的钙化潜力也将得到测试，其中包括建立新的文化。为了进一步研究蓝藻控制叠层石的形成，蓝藻从水设置显着不同的石灰华小溪需要进行调查，因此，分层的微生物垫在圣诞岛（Kiritimati）的高盐环境将被选中。石灰华溪生物膜的分类组成的季节性变化可能作为一个可能的额外的驱动力的石灰华形成，将使用快速分子方法进行评估。上一个项目阶段的结果表明，硅藻以外的真核藻类的多样性与钙化的关系可能被低估了，因此将在这里使用非培养方法进行进一步评估。

To verify and further elucidate taxon-specific activities of cyanobacteria and microalgae in stromatolite formation is the main goal of this project. In the previous project phase key player cyanobacteria and diatoms from two exemplar tufa creeks were revealed and it is now needed to explore their in situ abundances and distribution patterns in relation to CaCO3 precipitates and CaCO3-free areas. This will be visualized by rRNA-targeted Fluorescence In Situ Hybridization. The calcification potential of the key player cyanobacteria and algae will be tested as well which includes the establishment of new cultures as well. To further investigate the cyanobacterial control of stromatolite formation, cyanobacteria from a water setting significantly different from the tufa creeks need to be investigated and, therefore, the stratified microbial mats in the hypersaline environment at Christmas island (Kiritimati) will be selected. Seasonal changes in the taxonomic composition of the tufa creek biofilms may act as a possible additional driving force of tufa formation which will be assessed using rapid molecular methods. Results from the previous project phase indicate that the diversity of eukaryotic algae other than diatoms in relation to calcification may yet have been underestimated and thus it will be further evaluated here using culture-independent methods.