Microbial Ecology of Thermophilic Phototrophs

Thermophilic phototrophs are heat-adapted microorganisms that harness light energy in environments such as hot springs and hydrothermal vents. These organisms encompass both oxygenic and anoxygenic phototrophs, including deeply branched cyanobacteria, members of the Chloroflexota phylum, and other lesser-studied lineages. In microbial mats, thermophilic phototrophs form stratified communities in which light capture, nutrient cycling and redox reactions are tightly coupled. Oxygen-producing cyanobacteria often occupy surface layers, supplying organic carbon and oxygen to underlying anoxygenic phototrophs that utilise bacteriochlorophylls and specialised light-harvesting structures called chlorosomes. Interactions within these communities underpin global biogeochemical cycles, driving primary production in extreme habitats and offering models for early Earth ecosystems. Advances in cultivation, genomic and transcriptomic analyses have revealed modes of energy conversion, adaptive pigments tuned to infrared wavelengths and horizontal gene transfer events that reshaped phototrophic pathways. Understanding thermophilic phototroph ecology informs biotechnological applications—such as thermostable enzymes for renewable energy—and contributes to our knowledge of photosynthetic evolution under thermal stress.

Research from Nature Portfolio

Recent studies have described the discovery of a novel anoxygenic phototrophic bacterium within the Chloroflexota phylum that employs a type I reaction centre for light energy conversion. This organism bridges a phylogenetic gap by using a reaction centre architecture previously unobserved in its lineage and retains chlorosomes for efficient light capture. Phylogenomic analyses suggest that both type I and type II reaction-centre phototrophs in this phylum inherited phototrophy from a common ancestor, providing new context for the evolutionary diversification of photosynthetic systems. Environmental transcriptomic data demonstrate in situ activity of this strain in boreal shield lake and hot spring analogues, underscoring its ecological relevance and expanding our understanding of phototrophic innovation in high-temperature settings.

Microbial Ecology of Thermophilic Phototrophs publication trend

The graph below shows the total number of articles in microbial ecology of thermophilic phototrophs across all publications each year (not limited to Nature Index journals).

Technical terms

Thermophilic phototroph: A heat-tolerant organism that captures light energy to drive metabolism.

Anoxygenic photosynthesis: A form of photosynthesis that does not produce oxygen, typically using bacteriochlorophyll pigments and alternative electron donors.

Reaction centre: A protein complex in phototrophs where light-induced electron transfer initiates photosynthetic energy conversion; classified as type I or type II based on cofactors.

Chlorosome: A specialised light-harvesting organelle found in some anoxygenic phototrophs, containing dense arrays of bacteriochlorophyll molecules.

Horizontal gene transfer: The non-reproductive movement of genetic material between organisms, facilitating rapid acquisition of novel metabolic functions.

References

1. Anoxygenic phototroph of the Chloroflexota uses a type I reaction centre. Nature (2024).
2. Exploring the Origins and Evolution of Oxygenic and Anoxygenic Photosynthesis in Deeply Branched Cyanobacteriota. Molecular Biology and Evolution (2024).
3. Evolution of Phototrophy in the Chloroflexi Phylum Driven by Horizontal Gene Transfer. Frontiers in Microbiology (2018).