Effects of different sulfur sources on the growth and specific desulfurization activity of Rhodococcus erythropolis

It was found that R. erythropolis KA2-5-1 has an ability in using both organic and inorganic sulfur compounds as a sulfur source. Compared with taurine and magnesium sulfate, DBT is found being the best sulfur source for both strain growth and its specific desulfurization activity. The maximum specific desulfurization activity of 79.1mmol 2HBP·kg~(-1)·h~(-1) was obtained when initial DBT concentration was at 11.5mg·l~(-1). The factors affecting specific desulfurization activity are suggested as diferrent growth phase, adding amount of DBT and the concentration of 2 hydroxybiphenyl production. Using DBT as a sole sulfur source and limiting its adding amount to the extent of only meeting 30% normal sulfur requirement of R. erythropolis KA2-5-1 is a optimal control method for the highest specific desulfurization activity.