FIG. 5.

Conversion of naphthalenecarbonitrile by the purified nitrilase from Synechocystis sp. strain PCC6803 in the presence of different volumes of hexadecane. The reaction mixtures contained 580 μg of the purified (His-tagged) nitrilase in 200 μl of 50 mM Na-K phosphate buffer (pH 7.0) plus 10 mM naphthalenecarbonitrile. Different volumes of hexane were added (0% [vol/vol] [•], 20% [vol/vol] [○], 40% [vol/vol] [▪], or 60% [vol/vol] [□]), and the reaction mixtures were shaken at 30°C in a Thermomixer at 1,000 rpm. The reactions were stopped after different time intervals by the addition of 10% (vol/vol) 1 M HCl. Precipitated protein was removed by centrifugation (2 min, 16,000 × g), and the concentration of ammonia formed was determined in the aqueous phase by using the Spectroquant ammonia test.