Study on growth characteristic and microbial desulfurization activity of the bacterial stain MP12

• DMSO was the most suitable sulfur source for growth and desulfurization activity.
• 2-HBP concentration had significant effects on growth and desulfurization activity.
• Developed a novel method to measure desulfurization activity in crude oil system.
• MP12 can desulfurize organic sulfur compounds in both DBT and crude oil systems.

The growth characteristic and interrelated microbial desulfurization activity of stain MP12 on both DBT and crude oil systems were investigated in order to desulfurize crude oil. The results showed that DMSO was the most suitable sulfur source for stain MP12 growth and expression of desulfurization activity, while initial 2-HBP had very significant influences on the growth and desulfurization activity. Moreover, a novel method using the production rate of sulfate was developed for rapid determination of desulfurization activity in crude oil system. Analysis of total 2-HBP and total sulfate molar balance suggested that the total 2-HBP buildup had a very good match with the total sulfate buildup during microbial desulfurization of crude oil. The desulfurization activity of high density cells could be increased sharply with an increase of agitation speed. In conclusion, the strain MP12 was able to effectively desulfurize recalcitrant organic sulfur compounds in both DBT and crude oil systems.