Designer transgenic algae for photobiological production of hydrogen from water

Abstract

This chapter reports two inventions: designer proton-channel algae (US Patent No. 7,932,437 B2) and designer switchable photosystem-II algae (US Patent No. 7,642,405 B2), for more efficient and robust photobiological production of hydrogen (H2) from water. Use of these inventions could eliminate the following six technical problems that severely limit the yield of algal H2 production: (1) restriction of photosynthetic H2 production by accumulation of a proton gradient, (2) competitive inhibition of photosynthetic H2 production by CO2, (3) requirement of bicarbonate binding at photosystem-II (PSII) for efficient photosynthetic activity, (4) competitive drainage of electrons by O2 in algal H2 production, (5) oxygen sensitivity of algal hydrogenase, and (6) the H2-O2 gas separation and safety issue. By eliminating these six technical problems that currently challenge those in the field, the designer algae approach could enhance photobiological production of hydrogen with a yield likely over ten times better than that of the wild-type.