초록
<P>Resting cells of <I>Gordonia terrae</I> with nitrilase (EC 3.5.5.1) activity were investigated for transformation of <I>p-</I>hydroxybenzonitrile to <I>p-</I>hydroxybenzoic acid. The maximum conversion was observed in 0.1 M potassium phosphate buffer, pH 8.0, using 40 mM substrate and resting cells corresponding to 0.70 Uml<SUP>− 1</SUP> nitrilase activity at 35°C. A 500 mL fed batch reaction was designed for synthesis of <I>p-</I>hydroxybenzoic acid with six feedings of substrate at an interval of 1 h. A total of 14.4 g of <I>p-</I>hydroxybenzoic acid (> 98.7%) was obtained in 6 h with a productivity of 0.78 gh<SUP>− 1</SUP>g<SUP>− 1</SUP><SUB>DCW</SUB> of <I>G. terrae.</I></P>