Enzymatic Synthesis of Pyruvic Acid and L-Lactic Acid from Carbon Dioxide

The emission of carbon dioxide has become a serious problem because of recent global warming. The increase in global carbon dioxide levels over the last hundred years or more have been reported. Several efforts to immobilize or utilize carbon dioxide have been achieved. Recent interest in the problems of environmental pollution has forced the development of a green chemistry process for the chemical industry. Several environment-friendly processes have been developed. Biocatalytic processes such as fermentation and enzyme reactions have attracted attention as environmentally safe chemical process. Biodegradable polymers have also proved interesting for environmental safety. Among the biodegradable plastics, poly(L-lactic acid) has been widely studied. Several methods have been developed to produce lactic acid from many sources. However, most of them produce the racemic form and require relatively longer time and multiple steps to obtain pure L-lactic acid. These disadvantages are problematic, not only for large-scale production but also for environmental safety. Therefore, a simple method, that can produce optically pure L-lactic acid, is desired. A new enzymatic synthesis of pyruvic acid and L-lactic acid from acetaldehyde and carbon dioxide has been developed. The reaction of pyruvic acid synthesis utilizes reverse reaction of pyruvate decarboxylase in sodium bicarbonate buffer.