Table 2. Performance statistics of the modified Gompertz model during training and validation periods for the modeling of growth curves of strain SL2 under Cr(VI) stress.

Cr(VI) concentration	Training			Validation
	R2	MSE	NS	R2	MSE	NS
0 mg/L	0.996	0.023	0.996	0.984	0.078	0.975
100 mg/L	0.997	0.009	0.996	0.996	0.014	0.994
400 mg/L	0.990	0.018	0.989	0.991	0.020	0.987
1000 mg/L	0.993	0.004	0.993	0.986	0.008	0.986

R², coefficient of determination; MSE, mean squared error; NS, Nash–Sutcliffe efficiency coefficient.