20-EPN-61: Life in extreme environments: Distribution and importance of far-red light driven photosynthesis to primary production in Martian-like environments
Visit by Dennis Nürnberg, Freie Universität Berlin, (Germany) and Daniel Canniffe, Liverpool University (UK) to TA1.5 Makgadikgadi Salt Pans (Botswana).
Dates of visit: 10-19 February 2022
The aim of this project was to confirm the richness and abundance of chlorophyll f-containing cyanobacteria, and their ability to use low-energy light to perform oxygenic photosynthesis in Martian-like environments. This study was a follow-up to a 2019 sampling trip to the sabkhas of the Western Sahara (Morocco), for which we could show that chlorophyll f-cyanobacteria are highly abundant. Here we expanded this research by collecting samples from the hypersaline environments of the Sua and Ntwetwe Pans in Makgadikgadi (Botswana). Microbial mat and rock samples containing endolithic and hypolithic phototrophs were collected. Light microscopy on site confirmed the abundance of cyanobacteria of various morphologies in most collected samples. The microbial mat samples were especially rich in cyanobacteria, forming a 1-2 mm thick layer at various depths depending on the absorption properties of the top layer.
Preliminary analyses with high-performance liquid chromatography (HPLC) in combination with hyperspectral confocal fluorescence microscopy confirmed the presence of red-shifted chlorophylls in some of these samples but to less extent as observed in the sabkhas. Genomic DNA has been extracted and will be used for sequencing and phylogenetic analyses based on 16S rRNA and specific far-red light genes. This will allow to fully evaluate the microbial diversity and their ability to perform chlorophyll f-driven oxygenic photosynthesis. In addition, the enrichment and isolation process of new chlorophyll f-containing cyanobacteria has been started by transferring the samples to growth media of various salinity and keeping them under selective far-red light illumination.
Read full report, published with kind permission by Dr Nürnberg and Dr Canniffe.