Bioconversion of CO to ethanol and other compounds

The light-driven process of CO, fixation and its conversion into a myriad of larger organic molecules is a remarkably successful strategy employed by all plants. Likewise, there are numerous types of bacteria that are capable of extremely efficient CO, fixation, including those that use light-driven processes, as well as several species that are capable of using the energy obtained from chemical oxidations to fuel CO, reduction in the dark. However, nowhere in nature can an organism be found that has coupled CO, fixation to significant ethanol production. With the realization that fully one-third of the corn starch used for biological ethanol formation is lost through the production of CO, gas, it would be desirable to discover some way to use this CO, for the production of value-added chemicals or other products of interest. In this paper, we discuss recent experiments to couple the metabolism of CO, to the synthesis of ethanol using recombinant DNA technology. A chimeric bacterium was constructed so that CO, may be metabolized to ethanol.