Modes of carbon fixation in an arsenic and CO₂-rich shallow hydrothermal ecosystem.

ABSTRACT: The seafloor sediments of Spathi Bay, Milos Island, Greece, are part of the largest arsenic-CO₂-rich shallow submarine hydrothermal ecosystem on Earth. Here, white and brown deposits cap chemically distinct sediments with varying hydrothermal influence. All sediments contain abundant genes for autotrophic carbon fixation used in the Calvin-Benson-Bassham (CBB) and reverse tricaboxylic acid (rTCA) cycles. Both forms of RuBisCO, together with ATP citrate lyase genes in the rTCA cycle, increase with distance from the active hydrothermal centres and decrease with sediment depth. Clustering of RuBisCO Form II with a highly prevalent Zetaproteobacteria 16S rRNA gene density infers that iron-oxidizing bacteria contribute significantly to the sediment CBB cycle gene content. Three clust

SUBMITTER: Callac N 

PROVIDER: S-EPMC5665909 | biostudies-literature | 2017 Oct

REPOSITORIES: biostudies-literature