Hydrogen is widely accepted as a potential substitute for fossil fuels. Biological hydrogen production stands out as an environmentally harmless process carried out under mild operating conditions, using renewable resources. This book introduces the biological hydrogen production concept to the reader by providing a general knowledge on the subject. Then, original research results were presented and discussed. These include the effects of the physiological conditions such as the nutrient media composition on hydrogen production in photosynthetic bacteria, and the improvement of the...