Continuous Desulfurization of Dibenzothiophene with Rhodococcus rhodochrous IGTS8 (ATCC 53968)

• Published in: Biotechnology progress 2002, Vol.18 (6), p.1207-1213
• Main Authors: Schilling, Bernhard M., Alvarez, Luis M., Wang, Daniel I. C., Cooney, Charles L.
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Fundamental and applied biological sciences. Psychology
• ISSN: 8756-7938; 1520-6033
• DOI: 10.1021/bp0200144

Desulfurization of a model fuel system consisting of hexadecane and dibenzothiophene (DBT) by Rhodococcus rhodochrousIGTS8 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.