There a many aerobic (i.e., Knallgas bacteria (chemolithoautotrophs) using H2/02/CO2 as energy / reductant and as carbon source, respectively, photolithoautotrophhs) and anaerobic bacteria and archaea (e.g., acetogenic bacteria, carbonmoxide utilizer, methanogenogens etc.) which fix CO2, i.e. using it a carbon source. Look up under autotrophic bacteria, i.e., bacteria using CO2 / CO as sole carbon source. Furthermore, there are several biochemical pathways used by various taxa. (If the terms are unfamiliar to you, I suggest to google them / Wikepedia).

There are many reviews / bookchapters on lithoautotrophic (or in short autotrophic) microorganisms.

This publication could be interesting for you:

http://www.ncbi.nlm.nih.gov/pubmed/24337298

"Direct and reversible hydrogenation of CO2 to formate by a bacterial carbon dioxide reductase" published in Science 2013 342(6164):1382-5

(doi: 10.1126/science.1244758.) by Schuchmann K and Müller V.

Best regards

Autotrophic microbe

Cyanobacteria can act as primary producers (autotrophic carbon fixing) in those soils in which plants hardly can live

Streptococcus pneumoniae can use CO2 as a source for fatty acid synthesis.

There a many aerobic (i.e., Knallgas bacteria (chemolithoautotrophs) using H2/02/CO2 as energy / reductant and as carbon source, respectively, photolithoautotrophhs) and anaerobic bacteria and archaea (e.g., acetogenic bacteria, carbonmoxide utilizer, methanogenogens etc.) which fix CO2, i.e. using it a carbon source. Look up under autotrophic bacteria, i.e., bacteria using CO2 / CO as sole carbon source. Furthermore, there are several biochemical pathways used by various taxa. (If the terms are unfamiliar to you, I suggest to google them / Wikepedia).

There are many reviews / bookchapters on lithoautotrophic (or in short autotrophic) microorganisms.