The Fed-Batch Production of a Thermophilic 2-Deoxyribose-5-Phosphate Aldolase (DERA) in Escherichia coli by Exponential Feeding Strategy Control

Abstract

2-Deoxyribose-5-phosphate aldolase (DERA) catalyzes a sequential aldol reaction useful in synthetic chemistry. In this work, the effect of a feeding strategy on the production of a thermophilic DERA was investigated in fed-batch cultures of recombinant Escherichia coli BL21 (pET303-DERA008). The predetermined specific growth rate (micro(set)) was evaluated at 0.20, 0.15, and 0.10 h(-1), respectively. The DERA concentration and volumetric productivity were associated with micro(set). The cells synthesized the enzyme most efficiently at micro(set) = 0.15 h(-1). The maximum enzyme concentration (5.12 g/L) and total volumetric productivity (0.256 g L(-1) h(-1)) obtained were over 10 and five times higher than that from traditional batch cultures. Furthermore, the acetate concentration remained at a relatively low level, less than 0.4 g/L, under this condition which would not inhibit cell growth and target protein expression. Thus, a specific growth rate control strategy has been successfully applied to induce fed-batch cultures for the maximal production of the thermophilic 2-deoxyribose-5-phosphate aldolase.