Optimization of the ferrous iron liquid growth medium for thiobacillus ferrooxidans (DSM583) by the design of experiment (D.O.E.) methodology

摘要

The methodology of Design of Experiment was successfully applied for determining the optimal composition of a growth medium for Thiobacillus ferrooxidans DSM583. In order to increase the bacterial concentration in ferrous liquid medium, its composition was optimised at pH 1.4 and 30 deg C in 100-ml shake flasks through a two-step methodology. The objective of the first design was a screening for pointing out the most important parameters among 13 tested (agitation rate and concentrations of 12 chemical compounds). A second design was then carried out (D-optimal design) for the 6 majors parameters (FeSO_4, (NH_4)_2SO_4, K_2HPO_4, CuSO_4, ZnSO_4 and H_3BO_3) with three fixed parameters (agitation rate and CaSO_4, MgSO_4 concentrations). The optimised composition of the medium providing the higher bacterical concentration was found to be (in g L~(-1): FeSO_4(100), (NH_4)_2SO_4(10), K_2HPO_4(10), CuSO_4(0.001), ZnSO_4(0.001), H_3BO_3(0.001), CaSO_4(0.001), and MgSO_4(0.1).