Production of l-AA by a Two-Step Fermentation Process

Though the Reichstein process was applied for the industrial-scale production of l-AA for many years, the disadvantages of the process include low yield, high energy consumption, high amount of the organic solvent required, and serious environmental pollution. Therefore, many researchers have attempted to improve the performance of classical Reichstein process. 

The classical two-step fermentation process is the most successful process for l-AA production. During the two-step fermentation process, the final yield of L-sorbose on D-sorbitol is more than 99.5%, while the yield of 2-KLG on L-sorbose is more than 97%. Very few of the current industrial bioprocesses can achieve such yields. The whole classical two-step fermentation process yield is more than 90% of l-AA from glucose feed on the industrial scale, which is much higher than that of the Reichstein process. 

To achieve even better production of 2-KLG, much work has been performed to understand the mutuahsm process oiK. vulgare and . megaterium [21-26]. Rapid development of systems biology significantly facilitated this research [27]. 

Genome sequencing of the three bacteria involved in the process provided many useful clues for understanding and improving the mutuahsm process. Reconstruction and analysis of genome-scale metabohc models of these bacteria facilitate the development of even comphcated mutuahsm models and potential metabolic engineering strategies [28]. 

8For industrial goals, the mutuahsm between the two bacteria is a big problem. 

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