1. Metataxonomy and pigments analyses unravel microbial diversity and the relevance of retinal-based photoheterotrophy at different salinities in the Odiel Salterns (SW, Spain).
- Author
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Gómez-Villegas P, Pérez-Rodríguez M, Porres JM, Prados JC, Melguizo C, Vigara J, Moreno-Garrido I, and León R
- Subjects
- Spain, Photosynthesis, RNA, Ribosomal, 18S genetics, Chlorophyll A metabolism, Seawater microbiology, Seawater chemistry, Bacteria metabolism, Bacteria genetics, Bacteria classification, Retinaldehyde metabolism, Retinaldehyde chemistry, Phylogeny, Chlorophyll metabolism, Chlorophyll chemistry, Biodiversity, Salinity, RNA, Ribosomal, 16S genetics
- Abstract
Salinity has a strong influence on microorganisms distribution patterns and consequently on the relevance of photoheterotrophic metabolism, which since the discovery of proteorhodopsins is considered the main contributor to solar energy capture on the surface of the oceans. Solar salterns constitute an exceptional system for the simultaneous study of several salt concentrations, ranging from seawater, the most abundant environment on Earth, to saturated brine, one of the most extreme, which has been scarcely studied. In this study, pigment composition across the salinity gradient has been analyzed by spectrophotometry and RP-HPLC, and the influence of salinity on microbial diversity of the three domains of life has been evaluated by a metataxonomic study targeting hypervariable regions of 16S and 18S rRNA genes. Furthermore, based on the chlorophyll a and retinal content, we have estimated the relative abundance of rhodopsins and photosynthetic reaction centers, concluding that there is a strong correlation between the retinal/chlorophyll a ratio and salinity. Retinal-based photoheterotrophy is particularly important for prokaryotic survival in hypersaline environments, surpassing the sunlight energy captured by photosynthesis, and being more relevant as salinity increases. This fact has implications for understanding the survival of microorganisms in extreme conditions and the energy dynamics in solar salter ponds., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)
- Published
- 2024
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