Table 2.

Comparison of the relative nitrile hydrolysing activities of cell extracts from Exophiala oligosperma R1, Fusarium solani O1, Penicillium multicolor CCF 2244 and the purified nitrilase from Aspergillus niger K1.

Substrate	E. oligosperma R1		P. multicolor CCF 22441(whole cells)	F. solani O12(purified enzyme)	A. niger K13(purified enzyme)
	Relative activity (%)	Formation of amide (% of total products)	Relative activity (%)	Relative activity (%)	Relative activity (%)
Benzonitrile	100	nd	100	100	100
2-Tolunitrile	≤5	nd	nd	ndm	nd
3-Tolunitrile	154	nd	11.3	33	5.5
4-Tolunitrile	16	nd	nd	16	3.4
2-Hydroxybenzonitrile	≤5	nd	nd	ndm	nd
3-Hydroxybenzonitrile	140	nd	0.8	80	5.8
4-Hydroxybenzonitrile	10	nd	nd	3	nd
2-Chlorobenzonitrile	<10	29	nd	ndm	nd
3-Chlorobenzonitrile	100	<5	14.3	87	41
4-Chlorobenzonitrile	49	nd	2.8	40	29.8
2-Cyanopyridine	<10	nd	40	ndm	14.2
Picolinic amide	nd	-	nd	ndm	-
3-Cyanopyridine	208	nd	15	28	32.4
Nicotinic amide	nd	-	18	ndm	-
4-Cyanopyridine	566	<10	72	130	410.7
Isonicotinic amide	<5	-	nd	ndm	-
Phenylacetonitrile	19	nd	2.3	ndm	10.8
2-Chlorophenylacetonitrile	11	nd	ndm	ndm	ndm
3-Chlorophenylacetonitrile	35	nd	ndm	ndm	ndm
4-Chlorophenylacetonitrile	22	nd	ndm	ndm	ndm
Mandelonitrile	<5	Traces	ndm	ndm	ndm
2-Phenylpropionitrile	<10	nd	nd	nd	1
Acrylonitrile	121	<10	ndm	ndm	ndm

Cell extracts of E. oligosperma R1 were produced as described in the materials and methods section. The reaction mixtures (750 μL each) contained 0.1 M Tris/HCl (pH 7) and 0.2 mg/mL of protein and were incubated in 1.5 mL cups in a thermoshaker (30 °C, 1 400 rpm). The reactions were started by the addition of the respective substrates (2 mM each). At different time intervals samples were taken, and the reactions terminated by the addition of 20 % (v/v) 1 M HCl. The reaction mixtures were centrifuged (21 000 g, 10 min, 4 °C) and the supernatants analysed by HPLC according to the procedures described in the material and method section. The reaction rates were calculated from the turn-over of the substrates. The activity of benzonitrile was taken as 100 % (0.48 U/mg of protein).

^1,2,The data for the Penicillium, and the Aspergillus strains were adapted from Kaplan et al. (2006a, c) and ³ those for the Fusarium strain from Vejvoda et al. 2008, nd: not detected; nd_m: not determined.