Morphological identification of microalgae and Cyanobacteria is hampered by few morphological features and phenotypical plasticity as response to environmental factors. Therefore, it is difficult to distinguish different species especially for the group of picocyanobacteria. In the past, also the taxonomy of eukaryotic algae was often misinterpreted due to the lack of sufficient morphological features. More and more modern genetic methods based on DNA were used to reliable define a species. In addition, the DNA sequence of a gene can also be used to analyze the phylogeny of a specific alga or the distribution of a population. Analysing the DNA of a whole environmental sample allows the culture-independent determination of their biodiversity and the abundance of different taxonomic groups (e. g. algae, cyanobacteria, fungi).
Albrecht, M., Pröschold, T., and Schumann, R. (2017) Identification of cyanobacteria in a eutrophic coastal lagoon on the southern Baltic coast. Frontiers in Microbiology 8, 923. DOI: 10.3389/fmicb.2017.00923
Our fully equipped molecular lab allows the analyses of genes from different organisms or environmental samples using DNA isolation, amplification (PCR) and cloning. Further, the sequenced genes will be processed by established bioinformatic methods uncovering the phylogeny of each species. Biodiversity estimation of environmental samples can be conducted using different fingerprint techniques like denaturing gradient gel electrophoresis (DGGE) and Terminal restriction fragment length polymorphism (TRFLP).
We also use modern high-throughput sequencing (“next-generation-sequencing”) to analyze diversity and community composition of different organism groups: bacteria (in cooperation with DSMZ Braunschweig), Cercozoa as specific protist group (in coop. with Uni Cologne) and fungi (in coop. with UFZ Halle). Thus, we are able to detect the most important microorganism in soil. Further, high-throughput sequencing was used for the analyses of the complete genepool (metagenomic) with focus on functional genes involved in biogeochemical nutrient cycling. The complete transcriptome was compared between cultures under environmental stress to reveal the stress response on genetic level.
Rippin M, Lange S, Sausen N, Becker B. 2018. Biodiversity of biological soil crusts from the Polar Regions revealed by metabarcoding. FEMS Microbiology Ecology 94.
Fiore-Donno AM, Rixen C, Rippin M, Glaser K, Samolov E, Karsten U, Becker B, Bonkowski M. 2018. New barcoded primers for efficient retrieval of cercozoan sequences in high-throughput environmental diversity surveys, with emphasis on worldwide biological soil crusts. Molecular Ecology Resources 18:229–239.