Heterotrophic microorganisms use organic compounds as carbon and energy sources to fix a small amount of CO2 during their own metabolism.
Autotrophic microorganisms absorb CO2 by using light energy or chemical energy generated by inorganic oxidation, and form cellular substances.
Eutrophication fixation is a combined fixation method in which microorganisms use light energy to absorb and transform CO2, and at the same time use organic carbon as supplementary carbon source and energy source.
There are differences in principle between the two microorganisms in fixing CO2: heterotrophic microorganisms fix CO2 on receptor molecules, but the receptor molecules are not synthesized from CO2; Autotrophic microorganisms fix CO2, and the receptor is synthesized from CO2, and the process can be recycled.
The ability of autotrophic microorganisms to fix CO2 far exceeds that of heterotrophic microorganisms. Therefore, at present, the relevant research in the world is centered on autotrophic microorganisms.
Autotrophic microorganisms are mainly divided into two categories: photoautotrophic microorganisms and chemoautotrophic microorganisms. The former uses light as energy source, while the latter uses reducing compounds such as 1- 12, H2S, S2032- 1, S, NH4+, NO2- and Fe2+ as energy source.
In fact, microbial carbon fixation generates new material energy, which means that autotrophic microorganisms absorb and transform CO2 by absorbing light energy or chemical energy, thus generating new material energy that can be used by us, turning waste into treasure, thus forming a virtuous cycle route for producing renewable resources.