Continuous desulfurization of dibenzothiophene with Rhodococcusrhodochrous IGTS8 (ATCC 53968).
Desulfurization of a model fuel system consisting of hexadecane and dibenzothiophene (DBT) by Rhodococcus rhodochrous IGTS8 was demonstrated in a 2-L continuous stirred tank reactor (CSTR). The reactor was operated in a semicontinuous and continuous mode with and without recycling of the model fuel. A constant volumetric desulfurization activity A(t), (in mg HBP L(-1) h(-1)) was maintained in the reactor with a feeding strategy of fresh cell suspension based on a first-order decay of the biocatalyst. Maximum desulfurization rates, as measured by specific desulfurization activity, of 1.9 mg HBP/g DCW h were attained. Rates of biocatalyst decay were on the order of 0.072 h(-1). Theoretical predictions of a respiratory quotient (RQ) associated with this biotransformation reaction agree well with experimental data from off-gas analysis. In addition, the ratio of the specific desulfurization activity a(t), (in mg HBP/g DCW h) of recycled and fresh biocatalyst was determined and evaluated.
Schilling
Bernhard M
BM
Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
Alvarez
Luis M
LM
Wang
Daniel I C
DI
Cooney
Charles L
CL
D019149:Bioreactors; D001711:Biotransformation; D007700:Kinetics; D012240:Rhodococcus / Q000254:growth & development / Q000378:metabolism*; D013447:Sulfites / Q000378:metabolism*; D013876:Thiophenes / Q000378:metabolism*
D013447:Sulfites; D013876:Thiophenes; C016366:dibenzothiophene