Engineering of corynebacterium glutamicum for the enhanced production of gamma-aminobutyric acid from glucose and xylose

Abstract

As fossil fuel depletion and climate change has been serious, lignocellulosic biomass has attracted attention. Lignocellulosic hydrolysates contain a large amount of glucose and xylose, but due to the rare strains that can efficiently use xylose, it was rarely used as actual sources. In this study, this problem was solved by using the strain that has already been adaptively evolved in 3.6 g/L xylose. In addition, a gamma aminobutyric acid, GABA, production pathway was constructed in the ALE strain. GabT, GabD, and GabP genes were deleted to enhance GABA production. However, when high concentration glucose was present, xylose was rarely consumed. Thus, the new adaptive evolution was performed under the relatively high concentration of xylose. The newly adaptively evolved strain showed a better growth curve than the parent strain under glucose and xylose mixed conditions. If the newly discovered adaptive evolution strain is further engineered, a cell factory that produces gamma aminobutyric acid while simultaneously consuming glucose and xylose in lignocellulosic hydrolysates will be constructed.