1. Puffing up of dough, during making of dosa, idli or bread, is due to production of CO2 gas during the fermentation process.
2. Appearance of large holes in “swiss cheese” is due to CO2 produced during fermentation by the bacterium Propionibacterium sharmanii.
3. During secondary treatment of sewage in sewage treatment plants, a number of gases like methane, H2S and CO2 are produced during microbial digestion of organic compounds.
4. Methanogens(e.g. Methano bacterium) present in the rumen (a part of stomach) of cattle are being used in bio gas plants to produce bio gas as energy source.
