Isolation, identification and characterization of a novel Rhodococcus sp. strain in biodegradation of tetrahydrofuran and its medium optimization using sequential statistics-based experimental designs.

Abstract Statistics-based experimental designs were applied to optimize the culture conditions for tetrahydrofuran (THF) degradation by a newly isolated Rhodococcus sp. YYL that tolerates high THF concentrations. Single factor experiments were undertaken for determining the optimum range of each of four factors (initial pH and concentrations of K 2 HPO 4  · 3H 2 O, NH 4 Cl and yeast extract) and these factors were subsequently optimized using the response surface methodology. The Plackett–Burman design was used to identify three trace elements (Mg 2+ , Zn 2+ and Fe 2+ ) that significantly increased the THF degradation rate. The optimum conditions were found to be: 1.80 g/L NH 4 Cl, 0.81 g/L K 2 HPO 4  · 3H 2 O, 0.06 g/L yeast extract, 0.40 g/L MgSO 4  · 7H 2 O, 0.006 g/L ZnSO 4  · 7H 2 O, 0.024 g/L FeSO 4  · 7H 2 O, and an initial pH of 8.26. Under these optimized conditions, the maximum THF degradation rate increased to 137.60 mg THF h −1  g dry weight in Rhodococcus sp. YYL, which was nearly five times of that by the previously described THF degrading Rhodococcus strain.