Heterotrophic inorganic carbon fixation varies with temperature and resource availability in marine and soil bacterial isolates.

Heterotrophic bacteria from marine and soil environments fix inorganic carbon at rates influenced by temperature and resource levels, with up to 1.1% biomass contribution.

• Why it matters: Understanding heterotrophic inorganic carbon fixation (HICF) is crucial because it significantly impacts global carbon cycling, yet its regulation in heterotrophs remains poorly understood.
• What they did: The study used stable isotope probing on two bacterial species, Pseudomonas putida and Pseudoalteromonas carrageenovora, cultivated under different temperatures and resource conditions, measuring HICF at the bulk and single-cell levels.
• The result: HICF was most prominent during exponential growth at optimal temperatures and low resource availability, indicating environmental conditions where inorganic carbon fixation becomes more relevant, informing models of microbial carbon fluxes.