ABSTRACT
Microbial bio-alcohol production is achieved by fermentation mainly using carbohydrates as substrates, which are major components of biomass. Various types of microorganisms have the capacity to produce bio-alcohol and/or bio-hydrogen, however, for this chapter only hyperthermophiles will be discussed. Dependency and rapid consumption of fossil fuels result in significantly negative impacts on the environment. To combat such deteriorating trends and maintain sustainability, biofuels are rapidly considered to be a major alternative source of fuel. A biological or chemical process is needed to convert biomass into simple sugars that can be fermented by a particular microorganism. Depending on the microorganism, the type of alcohol fermentation can vary. Microbial hydrogen production has been found to be mainly from dark fermentation using complex biomass. Although they possess the metabolic pathways required for alcohol production, the yields are still quite low in comparison to other non-hyperthermophilic alcohol producing microorganisms.
