@article{JahnSchmidtMock2014, author = {Jahn, Martin T. and Schmidt, Katrin and Mock, Thomas}, title = {A novel cost effective and high-throughput isolation and identification method for marine microalgae}, series = {Plant Methods}, volume = {10}, journal = {Plant Methods}, number = {26}, doi = {10.1186/1746-4811-10-26}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-121255}, year = {2014}, abstract = {BACKROUND: Marine microalgae are of major ecologic and emerging economic importance. Biotechnological screening schemes of microalgae for specific traits and laboratory experiments to advance our knowledge on algal biology and evolution strongly benefit from culture collections reflecting a maximum of the natural inter- and intraspecific diversity. However, standard procedures for strain isolation and identification, namely DNA extraction, purification, amplification, sequencing and taxonomic identification still include considerable constraints increasing the time required to establish new cultures. RESULTS: In this study, we report a cost effective and high-throughput isolation and identification method for marine microalgae. The throughput was increased by applying strain isolation on plates and taxonomic identification by direct PCR (dPCR) of phylogenetic marker genes in combination with a novel sequencing electropherogram based screening method to assess the taxonomic diversity and identity of the isolated cultures. For validation of the effectiveness of this approach, we isolated and identified a range of unialgal cultures from natural phytoplankton communities sampled in the Arctic Ocean. These cultures include the isolate of a novel marine Chlorophyceae strain among several different diatoms. CONCLUSIONS: We provide an efficient and effective approach leading from natural phytoplankton communities to isolated and taxonomically identified algal strains in only a few weeks. Validated with sensitive Arctic phytoplankton, this approach overcomes the constraints of standard molecular characterisation and establishment of unialgal cultures."}, language = {en} } @article{JahnMarkertRyuetal.2016, author = {Jahn, Martin T. and Markert, Sebastian M. and Ryu, Taewoo and Ravasi, Timothy and Stigloher, Christian and Hentschel, Ute and Moitinho-Silva, Lucas}, title = {Shedding light on cell compartmentation in the candidate phylum Poribacteria by high resolution visualisation and transcriptional profiling}, series = {Scientific Reports}, volume = {6}, journal = {Scientific Reports}, number = {35860}, doi = {10.1038/srep35860}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-167513}, year = {2016}, abstract = {Assigning functions to uncultivated environmental microorganisms continues to be a challenging endeavour. Here, we present a new microscopy protocol for fluorescence in situ hybridisation-correlative light and electron microscopy (FISH-CLEM) that enabled, to our knowledge for the first time, the identification of single cells within their complex microenvironment at electron microscopy resolution. Members of the candidate phylum Poribacteria, common and uncultivated symbionts of marine sponges, were used towards this goal. Cellular 3D reconstructions revealed bipolar, spherical granules of low electron density, which likely represent carbon reserves. Poribacterial activity profiles were retrieved from prokaryotic enriched sponge metatranscriptomes using simulation-based optimised mapping. We observed high transcriptional activity for proteins related to bacterial microcompartments (BMC) and we resolved their subcellular localisation by combining FISH-CLEM with immunohistochemistry (IHC) on ultra-thin sponge tissue sections. In terms of functional relevance, we propose that the BMC-A region may be involved in 1,2-propanediol degradation. The FISH-IHC-CLEM approach was proven an effective toolkit to combine -omics approaches with functional studies and it should be widely applicable in environmental microbiology.}, language = {en} }