Using directed evolution to improve hydrogen production in chimeric hydrogenases from Clostridia species.

Hydrogenases are enzymes that play a key role in controlling excess reducing equivalents in both photosynthetic and anaerobic organisms. This enzyme is viewed as potentially important for the industrial generation of hydrogen gas; however, insufficient hydrogen production has impeded its use in a commercial process. Here, we explore the potential to circumvent this problem by directly evolving the Fe-Fe hydrogenase genes from two species of Clostridia bacteria.

Modeling the folding and hydrogen production of Clostridium acetobutylicum and Clostridium saccharobutylium mutants using electrostatic potential surfaces and molecular dynamics.

Electrostatic potential surfaces (EPS) were used with molecular dynamics to model the folding mechanisms and kinetics of hydrogenase mutants from wild types Clostridium acetobutylicum and Clostridium saccharobutylium. The purpose of the EPS approach was to incorporate long range electrostatic forces between widely separated regions of the mutants which contain 575 amino acids. Also, it was demonstrated that the ratio of positive to negative EPS of unfolded mutants could be used to predict the production of molecular hydrogen from the folded mutants.