Some of the gases obtained by microbial process are given below:
1. Ethanol is a byproduct formed during the fermentation process of molasses by Saccharomyces. It is a type of alcohol and a clean (smokeless) fuel mixed with petrol and diesel to prevent vehicular emission
2. Methane is a gaseous fuel that is obtained by microbial anaerobic decomposition of urban agricultural and industrial waste
3. Hydrogen fuel, released during bio-photolysis of water, in which bacteria perform photoreduction. It is considered as the fuel of the future as it is non-polluting and an efficient fuel
Fuels obtained from fossil fuels are nonrenewable and also polluting. Meanwhile, these fuels such as hydrogen, ethanol, and methane are the future fuels, because they burn cleaner with the same efficiency and are renewable