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Sub-lithic photosynthesis in hot desert habitats
Michal Gwizdala1,2, Pedro H Lebre3, Gillian Maggs-Kölling4
1Department of Physics, University of Pretoria, Lynnwood Road, Pretoria, 0002, South Africa.
Environmental Microbiology
|April 5, 2021
Summary
Desert pebbles filter sunlight, protecting hypolithic cyanobacteria. These microbes adapt to arid conditions with specific genes, showing resilience to light stress when hydrated.
Area of Science:
- Astrobiology
- Microbiology
- Ecology
Background:
- Photosynthetic microorganisms in hyper-arid deserts inhabit hypolithic habitats on translucent pebbles.
- These sub-lithic environments offer protection but alter light conditions.
Purpose of the Study:
- To investigate light transmission through quartz stones in the Namib Desert.
- To assess photosynthetic activity and adaptations of hypolithic cyanobacterial biofilms.
Main Methods:
- Fluorometric and spectroscopic analysis of light transmission.
- Biochemical pigment analysis.
- Metagenomic analysis of microbial communities.
Main Results:
- Quartz pebbles significantly reduced photon flux and filtered short wavelengths.
- Chlorophylls d and f were absent; Helical Carotenoid Protein genes were prevalent, indicating desiccation stress adaptation.
- Hypolithic communities showed no light stress under water-saturated conditions.
Conclusions:
- Hypolithic cyanobacteria in Namib Desert quartz pebbles are adapted to filtered light and desiccation.
- Further research into these unique microbial communities and their adaptations is warranted.
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