Enzymatic Production of Ascorbic Acid-2-phosphate by Recombinant Acid Phosphatase

In this study, an environmentally friendly and efficient enzymatic method for the synthesis of l -ascorbic acid-2-phosphate (AsA-2P) from l- ascorbic acid (AsA) was developed. The Pseudomonas aeruginosa acid phosphatase ( Pa APase) was expressed in Escherichia coli BL21. The optimal temperature, optimal pH, K m, k cat, and catalytic efficiency of recombinant Pa APase were 50 °C, 5.0, 93 mM, 4.2 s –1, and 2.7 mM –1 min –1, respectively. The maximal dry cell weight and Pa APase phosphorylating activity reached 8.5 g/L and 1127.7 U/L, respectively. The highest AsA-2P concentration (50.0 g/L) and the maximal conversion (39.2%) were obtained by incubating 75 g/L intact cells with 88 g/L AsA and 160 g/L sodium pyrophosphate under optimal conditions (0.1 mM Ca 2+, pH 4.0, 30 °C) for 10 h; the average AsA-2P production rate was 5.0 g/L/h, and the AsA-2P production system was successfully scaled up to a 7.5 L fermenter. Therefore, the enzymatic process showed great potential for production of AsA-2P in industry.