An isolated chemolithoautotrophic ecosystem deduced from environmental isotopes: Ayyalon cave (Israel)

The stable isotopes composition of chemolithoautotrophic cave ecosystems is known to differ from epigenic caves. Here we show that in addition, dead carbon (devoid 14 C), utilized and transferred throughout this ecosystem, rendering it unsuitable for radiocarbon dating. connectivity the Ayyalon Cave ecosystem with surface studied, along its sources energy carbon, as well interconnections between constituents. We use isotopic evidence ancient resilient based on an underground food web depending rich biomass production by nutrient supplies, detached photosynthesis. Carbon values indicate that: (1) microbial biota bicarbonate groundwater (23.34 pMC [% modern carbon]) rather than atmospheric CO 2 above water (71.36 pMC); (2) depleted C signal through entire indicating well-adapted biofilm which turn groundwater-dissolved inorganic carbon. Incubation C-labelled indicates uptake radio-labeled sulfur-oxidizing proteobacteria Beggiatoa , suggesting these microorganisms water-dissolved fixation. Organic matter much lighter nitrogen compared respective values, expected systems. This may be applicative subsurface voids Earth environments extraterrestrial