ABSTRACT
Carbon dioxide is a major gaseous pollutant released as a result o f burning carbonaceous material and it has been implicated in global warming. The utilization o f enzyme mixtures for continuous fixation o f carbon dioxide from emission sources has been reviewed. Two novel approaches have been recently developed for continuous fixation o f carbon dioxide in emis sion streams. The first is to capture the gaseous carbon dioxide from the emission stream and the second is a process to convert the captured carbon dioxide into concatenated carbon compounds. Capture o f carbon dioxide utilizes immobilized carbonic analydrase columns. Fixation o f carbon dioxide is achieved with a cohort o f enzymes that are divided into three modules. In the first module, carbon dioxide and ribulose bisphosphate (RuBP)is converted into 3-phophoglycerate (3PGA) catalyzed by Rubisco. In the second module, adenosine triphosphate (ATP) is generated using adenosine diphosphate (ADP) and inorganic phosphate is catalyzed by immobilized FOF1 ATPase. In the third module, a cohort o f enzymes converts 3PGA into RuBP for recycling in the first module. Excess 3PG A generated due to carbon dioxide fixation is extracted. This complex process therefore utilizes a number o f enzymes and results in continuous fixation o f the carbon dioxide generating concatenated compound 3-phosphoglycerate, the starting material for further enzymatic conversions resulting in other useful compounds o f commercial value. An overview o f these processes and their utilization o f enzyme mixtures is presented here.
