• 제목/요약/키워드: dibenzothiophene

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Desulfurization of Dibenzothiophene and Diesel Oil by Metabolically Engineered Escherichia coli

  • Park, Si-Jae;Lee, In-Su;Chang, Yong-Keun;Lee, Sang-Yup
    • Journal of Microbiology and Biotechnology
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    • 제13권4호
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    • pp.578-583
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    • 2003

  • The desulfurization genes (dszABC) were cloned from Gordonia nitida. Nucleotide sequences similarity between the dszABC genes of G. nitida and those of Rhodococcus rhodochrous IGTS8 was 89%. The similarities of deduced amino acids between the two were 86% for DszA, 86% for DszB, and 90% for DszC. The G. nitida dszABC genes were expressed in several different Escherichia coli strains under an inducible trc promoter. Cultivation of these metabolically engineered E. coli strains in the presence of 0.2 mM dibenzothiophene (DBT) allowed the conversion of DBT to 2-hydroxybiphenyl (2-HBP), which is the final metabolite of the sulfur-specific desulfurization pathway. The maximum conversion of DBT to 2-HBP was 16% in 60 h. Recombinant E. coli was applied for the deep desulfurization of diesel oil supplemented into the medium at 5% (v/v). Sulfur content in diesel oil was decreased from 250 mg sulfur/1 to 212.5 mg sulfur/1, resulting in the removal of 15% of sulfur in diesel oil in 60 h.

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황화 $Ni-W/\gamma-Al_2O_3$ 촉매에 의한 Dibeenzothiophene의 수첨탈황반응 (Hydrodesulfurization of Dibenzothiophene by Sulfided $Ni-W/\gamma-Al_2O_3$ Catalyst)

  • 김경림;정지원
    • 한국대기환경학회지
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    • 제2권2호
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    • pp.51-59
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    • 1986

  • Hydrodesulfurization of dibenzothiophene (DBT) dissolved in n-heptane was studied over sulfided $Ni - W/\gamma - Al_2O_3$ catalyst at temperature ranges from 513 to 573 K and at pressure ranges from 20 to 60 x $10^5$ Pa. Hydrogenation of biphenyl (BP) and cyclohexylbenzene (CHB) observed in products were also run. The products were almost biphenyl and cyclohyxylbenzene, and the conversion of DBT was very sensitive to temperature. Concerning the products distribution while the formation of biphenyl decreased, the formation of cyclohexylbenzene increased in the range of high pressure. The reaction network was found to be sequential reaction which formed cyclohexybenzent through the intermediate of biphenyl. The disappearances of DBT and biphenyl were the first order with respect to DBT and biphenyl and their activation energys were 24.3 and 13.6 Kcal/mol, respectively.

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Biodesulfurization of Dibenzothiophene and Its Derivatives Using Resting and Immobilized Cells of Sphingomonas subarctica T7b

  • Gunam, Ida Bagus Wayan;Yamamura, Kenta;Sujaya, I. Nengah;Antara, Nyoman Semadi;Aryanta, Wayan Redi;Tanaka, Michiko;Tomita, Fusao;Sone, Teruo;Asano, Kozo
    • Journal of Microbiology and Biotechnology
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    • 제23권4호
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    • pp.473-482
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    • 2013

  • The desulfurization ability of Sphingomonas subarctica T7b was evaluated using resting and immobilized cells with dibenzothiophene (DBT), alkyl DBTs, and commercial light gas oil (LGO) as the substrates. The resting cells of S. subarctica T7b degraded 239.2 mg of the initial 250 mg of DBT/l (1.36 mM) within 24 h at $27^{\circ}C$, while 127.5 mg of 2-hydroxybiphenyl (2-HBP)/l (0.75 mM) was formed, representing a 55% conversion of the DBT. The DBT desulfurization activity was significantly affected by the aqueous-to-oil phase ratio. In addition, the resting cells of S. subarctica T7b were able to desulfurize alkyl DBTs with long alkyl chains, although the desulfurization rate decreased with an increase in the total carbon number of the alkylated DBTs. LGO with a total sulfur content of 280 mg/l was desulfurized to 152 mg/l after 24 h of reaction. Cells immobilized by entrapment with polyvinyl alcohol (PVA) exhibited a high DBT desulfurization activity, including repeated use for more than 8 batch cycles without loss of biodesulfurization activity. The stability of the immobilized cells was better than that of the resting cells at different initial pHs, higher temperatures, and for DBT biodesulfurization in successive degradation cycles. The immobilized cells were also easily separated from the oil and water phases, giving this method great potential for oil biodesulfurization.

  • https://doi.org/10.4014/jmb.1207.07070 인용 PDF KSCI

돌연변이 균주 Gordona sp. EID의 dibenzothiophene 탈황 특성 (Characteristics of dibenzothiophene desulfurization by mutant Gordona sp. EID)

  • 조경숙;김윤정;성정현;류희욱;장용근
    • 청정기술
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    • 제5권2호
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    • pp.79-86
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    • 1999

  • 석유탈황용 균주인 Gordona sp. CYKS1을 ethylmethanesulfone 처리하여 돌연변이 균주 EID를 개발하여, dibenzothiophene(DBT) 탈황 특성을 조사하였다. EID 균주는 DBT를 2-hydroxybiphenyl(2-HBP)와 sulfate로 대사하는 4S pathway를 가지며, wild type인 CYKS1이 $2.6{\mu}mol{\cdot}L^{-1}{\cdot}h^{-1}$의 탈황속도를 보이는 반면, EID균주는 $4.0{\mu}mol{\cdot}L^{-1}{\cdot}h^{-1}$의 탈황속도를 나타내었다. 탄소원으로 공급된 glucose의 농도가 EID 균주의 DBT탈황속도에 미치는 영향을 조사한 결과 glucose의 농도가 증가할수록 탈황속도가 증가하였다. 또한, DBT 분해속도에 미치는 DBT의 초기 농도의 영향을 알아본 결과, 2.0 mM에서 최대 DBT 분해활성($11.1{\mu}mol{\cdot}L^{-1}{\cdot}h^{-1}$)을 나타내었다. 최종 대사산물인 2-HBP와 sulfate 농도가 증가할수록 EID 균주의 DBT 분해능은 감소하였다. 0.2 mM의 2-HBP를 첨가한 배지에서는 EID 균주의 성장과 DBT 탈황능은 완전 저해 받았다. Sulfate가 0.5g/L 첨가된 조건에서의 EID 균주의 DBT 탈황속도는 $1.4{\mu}mol{\cdot}L^{-1}{\cdot}h^{-1}$이었다.

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