Biohydrogen production from waste substrates as a clean energy

Demand of energy is increasing continuously due to rapid development in industrialization, population, economic growth, and rising living standards. Therefore, energy production is very important for living things, human and industrial activities. Hydrogen is a clean energy that has a great potential to be an alternative fuel. Hydrogen is an environmentally friendly fuel that possesses a high energy yield, provides clean energy generation without pollution when burned in air, and produces no greenhouse gases when combusted. It is an odorless, colorless, tasteless, and non-poisonous gas. Hydrogen is a sustainable energy system, which is produced from available sources and is used in every application where fossil fuels are being used in transportation, residential, commercial, and industrial sectors, and for electricity generation. In nature, some microorganisms with biological processes can produce hydrogen gas. In this review, biohydrogen production from industrial waste substrate, microbial producers, bioprocessing strategies, and the recent developments are discussed with their relative advantages.