Table 1.

Variables and their levels for arginine deiminase production by E. faecium sp. GR7.

Factor (g/L)	Low level star point (−α)	Low level factorial (−1)	Central point (0)	High level factorial (+1)	High level star point (+α)
A-tryptone	−0.23	0	15	30	40.23
B-lactose	−6.82	0	10	20	26.87
C-arginine	−6.82	0	10	20	26.817