Β-alanine production using whole-cell biocatalysts in recombinant Escherichia coli

In this study, we aimed at developing an efficient whole-cell biocatalytic process for bio-production of β-alanine (3-AP) from L-aspartate. To obtain the highly efficient whole-cell biocatalysts, L-aspartate-α-decarboxylase (ADC) from different donor organisms, including Escherichia coli, Corynebacterium glutamicum, and Bacillus subtilis were selected and systematically analyzed for their activities in E. coli. Among theses, E. coli BL21(DE3)/pET28a-panD_C.g showed the highest activity. The effects of induction temperature, incubation time, reaction temperature, reaction pH, metal ion additives and substrate concentration were subsequently evaluated to improve the whole-cell biocatalytic efficiency. The maximum 3-AP production could reach 24.8 g/L with a yield of 92.6% under the following optimal conditions: 37 °C, pH 6.0, 50 mM Fe²⁺, 40 g/L L-aspartate and reaction for 20 h. Taken together, this work established an efficient biotransformation process for the production of 3-AP using the whole E. coli expressing ADC from C. glutamicum.