Continuous production of l-phenylalanine from acetamidocinnamic acid using co-immobilized cells of Corynebacterium sp. and Paracoccus denitrificans

In order to produce l-phenylalanine efficiently from acetamidocinnamic acid with immobilized microbial cells, a two-step enzyme reaction using the acetamidocinnamate amidohydrolase activity of Corynebacterium sp. C-23 cells and the aminotransferase activity of Paracoccus denitrificans pFPr-1 cells was investigated. It was found that the useage of co-immobilized Corynebacterium sp. and P. denitrificans cells with κ-carrageenan was superior to that of the mixture of immobilized Corynebacterium sp. cells and immobilized P. denitrificans cells. When the space velocity was 0.06 h⁻¹ at 30°C, 147 mml-phenylalanine were produced with a 98% conversion ratio from acetamidocinnamic acid. The half-life of the l-phenylalanine-forming activity of the column was calculated to be ≈ 14 days at 30°C.