Kinetic analysis of microbial desulfurization of model and light gas oils containing multiple alkyl dibenzothiophenes

• Published in: Bioscience, biotechnology, and biochemistry Vol. 65; no. 2; pp. 298 - 304
• Main Authors: Kobayashi, M. (Petroleum Energy Center, Shimizu, Shizuoka (Japan)), Horiuchi, K, Yoshikawa, O, Hirasawa, K, Ishii, Y, Fujino, K, Sugiyama, H, Maruhashi, K
• Format: Journal Article
• Language: English
• Published: Tokyo Japan Society for Bioscience, Biotechnology, and Agrochemistry 01.02.2001; Japan Society for Bioscience Biotechnology and Agrochemistry; Oxford University Press
• Subjects: 2-hydroxybiphenyl; alkyl dibenzothiophene; alkyl dibenzothiophenes; BIODEGRADATION; Biodegradation, Environmental; Biological and medical sciences; Biotechnology; desulfurization; dibenzothiophene; Energy; Fuel Oils - analysis; Fundamental and applied biological sciences. Psychology; Industrial applications and implications. Economical aspects; Kinetics; light gas oil; Models, Chemical; PETROL; POLLUTION; Rhodococcus; RHODOCOCCUS (BACTERIA); Rhodococcus - metabolism; Rhodococcus erythropolis; sulfur; Sulfur - chemistry; SULPHUR; Thiophenes - chemistry; Thiophenes - metabolism; Use of microorganisms or biopolymers in fossil fuel recovery; Desulfurization; Sulfur Organic compounds; Rhodococcus erythropolis; Fuel desulfurization; Light gas oil; Kinetic model; Thiophene derivatives; Simulation; Reaction mechanism; Bacteria; Actinomycetes; Kinetics; Inhibition; Biological treatment
• ISSN: 0916-8451; 1347-6947
• DOI: 10.1271/bbb.65.298

The reaction mechanism of biodesulfurization was investigated using whole cells of Rhodococcus erythropolis KA2-5-1, which have the ability to convert dibenzothiophene (DBT) into 2-hydroxybiphenyl. The desulfurization patterns of alkyl DBTs were represented by the Michaeis-Menten equation. The values of rate constants, the limiting maximal velocity (V max ) and Michaelis constant (K m ), for desulfurization of alkyl DBTs were calculated. The relative desulfurization activities of various alkyl DBTs were reduced in proportion to the total carbon numbers of alkyl substituent groups. Alkyl DBTs that had a total of six carbons of alkyl substituent groups were not desulfurized. The type or position of alkyl substituent groups had little effect on desulfurization activity. The desulfurization activity of each alkyl DBT, when mixed together, was reduced. This phenomenon was caused by apparent competitive inhibition of substrates. Using the apparent competitive inhibition model, the desulfurization pattern of a multiple components system containing alkyl DBTs was elucidated. This model was also applicable for biodesulfurization of light gas oil.