Factors that affect bacterial ecology in hydrogen-producing anaerobic reactors

Abstract

Hydrogen has been studied as an alternative to traditional energy sources; it is a clean and renewable fuel that on combustion generates only water as a by-product. Biological production of hydrogen can occur either via photosynthesis or fermentation. The latter is technically simple and can convert substrates like organic matter present in wastewater into a renewable energy source. Microorganisms belonging to the domains Archaea and Bacteria are responsible for the conversion of various carbon sources to biogas, including hydrogen and methane. It is important to determine the microorganisms responsible for such transformations, as they are the major players of the process. Studying the bacterial diversity, population structure, and processes that modify these communities leads to a better understanding of their ecological functions and productivity. The environmental conditions within an anaerobic hydrogen reactor can exert a selective pressure on the community, thereby affecting the population structure, diversity, and heterogeneity. Combination of appropriate operational parameters and ecological factors could lead to the development of effective bioprocesses to maximize hydrogen yield. Therefore, the objective of this paper is to present a review on bacterial ecology in anaerobic hydrogen reactors and the factors that can affect bacterial diversity.