Fig 2.

Conversion of benzaldehyde and HCN to (R)-mandelonitrile by whole E. coli BL21(DE3) cells expressing wild-type AtHNL. All reactions were performed at 20°C using 350 mg of wet cells placed in nylon mesh (pore size, 0.4 μm). The reaction system consisted of 1 ml of 2 M HCN in buffer-saturated MTBE mixed with 0.5 mmol of benzaldehyde as the substrates. After each conversion round, the cells in the nylon mesh were washed with MTBE and placed in a fresh reaction vessel, and the subsequent conversion was started by the addition of new substrates. Symbols: □, first reaction cycle; ○, second reaction cycle; △, third reaction cycle. During all reaction cycles the ee exceeded 98%.