Hydrogen production: Photofermentation

Abstract

In this chapter, the production of hydrogen with purple nonsulfur (PNS) bacteria is presented, describing the main physiological features of PNS bacteria, the enzymes involved in H2production and the technological aspects related to the process of photofermentation. In particular, the conversion yields of the substrates, both synthetic and derived from waste products, utilized for H2production are presented, together with some considerations on the efficiency of the conversion of the light energy into hydrogen energy. The problems related with the scaling up of the process and with the use of solar light are finally discussed, presenting some of the open problems still to be solved in order to make this process economically feasible.