Isolation and identification of Thiobacillus ferrooxidans and optimization of its culture condition

Abstract:

[Objective] A strain with the ability of bioleaching was isolated. Its culture condition was optimized. [Methods] The strain was isolated from the soil collected from thermoelectric plant in Chengdu, whose taxonomic status was identified based on analysis of morphology characteristics, culture characteristics and 16S rDNA sequence. The optimization experiment was designed with Box-Behnken method in the software Design-Expert, in which the four factors of culture condition that initial pH, temperature, inoculum amount and liquid volume were investigated. Then the results were analyzed with the response surface analysis (RSA) and the optimal culture condition was determined. [Results] The isolated strain was Gram-negative and short-rod, which was named as Z1 and identified as Acidithiobacillus ferrooxidans strain by analysis of its 16S rDNA sequence. The optimal culture condition of the strain was determined, which was initial pH 1.8, optimum temperature 30 °C, inoculum volume 14% and liquid volume 60 mL medium in a 250 mL flask. Under the optimum condition, the oxidation rate of ferrousion reached at 99.7%. [Conclusion] The strain Z1 was appreciated for bioleaching.