Development of Corynebacterium glutamicum for enhanced production of γ-aminobutyric acid from glucose and xylose

Abstract

This research delves into the intricate dynamics of an Adaptive Laboratory Evolution (ALE) library, with a focus on isolating strains exhibiting superior performance. By refining the screening process for single strains, we identified and isolated strain 4A4, showcasing a remarkable 36-fold improvement in xylose consumption compared to the ALE parent strain, WJ108. Whole genome sequencing revealed a 24 kb large sequence, including xylBA, repeated 16.4 times. Controlled experiments confirmed that 16.4 copies of xylBA optimally enhanced the xylose consumption rate. Beyond the investigation into xylose consumption, the study's broader context involves the parallel pursuit of enhancing gamma-aminobutyric acid (GABA) production in C. glutamicum. Optimizations of media and culture conditions, including introducing peptone and adjusting pH to 6.0, achieved a best GABA titer of 59.55±2.01 g/L—setting a new benchmark.