Improvement of biodesulfurization rate by assembling nanosorbents on the surfaces of microbial cells.

To improve biodesulfurization rate is a key to industrialize biodesulfurization technology. The biodesulfurization rate is partially affected by transfer rate of substrates from organic phase to microbial cell. In this study, gamma-Al2O3 nanosorbents, which had the ability to selectively adsorb dibenzothiophene (DBT) from organic phase, were assembled on the surfaces of Pseudomonas delafieldii R-8 cell, a desulfurization strain. gamma-Al2O3 nanosorbents have the ability to adsorb DBT from oil phase, and the rate of adsorption was far higher than that of biodesulfurization. Thus, DBT can be quickly transferred to the biocatalyst surface where nanosorbents were located, which quickened DBT transfer from organic phase to biocatalyst surface and resulted in the increase of biodesulfurization rate. The desulfurization rate of the cells assembled with nanosorbents was approximately twofold higher than that of original cells. The cells assembled with nanosorbents were observed by a transmission electron microscope.