Research article | Highlight paper |
| 15 Apr 2025
The energy-efficient reductive tricarboxylic acid cycle drives carbon uptake and transfer to higher trophic levels within the Kueishantao shallow-water hydrothermal system
Joely M. Maak,Yu-Shih Lin,Enno Schefuß,Rebecca F. Aepfler,Li-Lian Liu,Marcus Elvert,and Solveig I. Bühring
This study presents new insights into autotrophic carbon fixation in shallow-water hydrothermal systems, emphasizing the dominance of reductive tricarboxylic acid (rTCA) cycle-utilizing Campylobacteria. Low isotopic fractionation values in vent fluids, possibly due to very acidic pH levels, extend the isotopic fractionation range of rTCA. The study also highlights the ecological significance of chemosynthetically fixed carbon, observed in higher trophic levels like the vent endemic crab Xenograpsus testudinatus, improving our understanding of carbon cycling in extreme environments and the interplay between microbial chemosynthesis and higher organisms.
This study presents new insights into autotrophic carbon fixation in shallow-water hydrothermal...
In acidic hot springs off Kueishantao, Campylobacteria fix CO2 by using the reductive tricarboxylic acid (rTCA) cycle, causing them to have an isotopically heavier biomass. Here, we report extremely low isotopic fractionation (of almost 0 ‰), which has never been reported in environmental samples. Moreover, the crab Xenograpsus testudinatus relies up to 34 % on campylobacterial biomass, highlighting the dependency of complex life on microscopic Bacteria in harsh environments.
In acidic hot springs off Kueishantao, Campylobacteria fix CO2 by using the reductive...