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Parravicini F, Brocca S, Lotti M. Evaluation of the Conformational Stability of Recombinant Desulfurizing Enzymes from a Newly Isolated Rhodococcus sp. Mol Biotechnol 2015; 58:1-11. [PMID: 26515071 DOI: 10.1007/s12033-015-9897-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Metabolic pathways of aerobic bacteria able to assimilate sulfur can provide biocatalysts for biodesulfurization of petroleum and of other sulfur-containing pollutants. Of major interest is the so-called "4S pathway," in that C-S bonds are specifically cleaved leaving the carbon skeleton of substrates intact. This pathway is carried out by four enzymes, named Dsz A, B, C, and D. In view of a possible application of recombinant Dsz enzymes in biodesulfurization treatments, we have investigated the structural features of enzymes cloned from a Rhodococcus strain isolated from polluted environmental samples and their resistance to temperature (20-95 °C) and to organic solvents (5, 10, and 20 % v/v methanol, acetonitrile, hexane, and toluene). Changes in protein structures were assessed by circular dichroism and intrinsic fluorescence spectroscopy. We found that all Dsz proteins are unfolded by temperatures in the range 45-60 °C and by all solvents tested, with the most dramatic effect being produced by toluene. These results suggest that stabilization of the biocatalysts by protein engineering will be necessary for developing biodesulfurization technologies based on Dsz enzymes.
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Affiliation(s)
- Federica Parravicini
- Department of Biotechnology and Biosciences, State University of Milano-Bicocca, Piazza della Scienza 2, 20126, Milan, Italy
| | - Stefania Brocca
- Department of Biotechnology and Biosciences, State University of Milano-Bicocca, Piazza della Scienza 2, 20126, Milan, Italy
| | - Marina Lotti
- Department of Biotechnology and Biosciences, State University of Milano-Bicocca, Piazza della Scienza 2, 20126, Milan, Italy.
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Biodesulfurization of a system containing synthetic fuel using Rhodococcus erythropolis ATCC 4277. Appl Biochem Biotechnol 2014; 174:2079-85. [PMID: 25163887 DOI: 10.1007/s12010-014-1189-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2014] [Accepted: 08/19/2014] [Indexed: 10/24/2022]
Abstract
The burning of fossil fuels has released a large quantity of pollutants into the atmosphere. In this context, sulfur dioxide is one of the most noxious gas which, on reacting with moist air, is transformed into sulfuric acid, causing the acid rain. In response, many countries have reformulated their legislation in order to enforce the commercialization of fuels with very low sulfur levels. The existing desulfurization processes cannot remove such low levels of sulfur and thus a biodesulfurization has been developed, where the degradation of sulfur occurs through the action of microorganisms. Rhodococcus erythropolis has been identified as one of the most promising bacteria for use in the biodesulfurization. In this study, the effectiveness of the strain R. erythropolis ATCC 4277 in the desulfurization of dibenzothiophene (DBT) was evaluated in a batch reactor using an organic phase (n-dodecane or diesel) concentrations of 20, 80, and 100 % (v/v). This strain was able to degrade 93.3, 98.0, and 95.5 % of the DBT in the presence of 20, 80, and 100 % (v/v) of dodecane, respectively. The highest value for the specific DBT degradation rate was 44 mmol DBT · kg DCW(-1) · h(-1), attained in the reactor containing 80 % (v/v) of n-dodecane as the organic phase.
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Choi SH, Kim K, Jeon J, Meka B, Bucella D, Pang K, Khatua S, Lee J, Churchill DG. Optical Effects of S-Oxidation and Mn+ Binding in meso-Thienyl Dipyrrin Systems and of Stepwise Bromination of 4,4-Difluoro-8-(2,5-dibromo-3-thienyl)-4-bora-3a,4a-diaza-s-indacene. Inorg Chem 2008; 47:11071-83. [DOI: 10.1021/ic801354y] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Shin Hei Choi
- Molecular Logic Gate Laboratory, Department of Chemistry and School of Molecular Science -BK 21, Korea Advanced Institute of Science and Technology (KAIST), 373-1 Guseong-dong, Yuseong-gu, Daejeon, 305-701, Republic of Korea, and Department of Chemistry, Columbia University, 3000 Broadway, New York, New York 10027
| | - Kibong Kim
- Molecular Logic Gate Laboratory, Department of Chemistry and School of Molecular Science -BK 21, Korea Advanced Institute of Science and Technology (KAIST), 373-1 Guseong-dong, Yuseong-gu, Daejeon, 305-701, Republic of Korea, and Department of Chemistry, Columbia University, 3000 Broadway, New York, New York 10027
| | - June Jeon
- Molecular Logic Gate Laboratory, Department of Chemistry and School of Molecular Science -BK 21, Korea Advanced Institute of Science and Technology (KAIST), 373-1 Guseong-dong, Yuseong-gu, Daejeon, 305-701, Republic of Korea, and Department of Chemistry, Columbia University, 3000 Broadway, New York, New York 10027
| | - Bhupal Meka
- Molecular Logic Gate Laboratory, Department of Chemistry and School of Molecular Science -BK 21, Korea Advanced Institute of Science and Technology (KAIST), 373-1 Guseong-dong, Yuseong-gu, Daejeon, 305-701, Republic of Korea, and Department of Chemistry, Columbia University, 3000 Broadway, New York, New York 10027
| | - Daniela Bucella
- Molecular Logic Gate Laboratory, Department of Chemistry and School of Molecular Science -BK 21, Korea Advanced Institute of Science and Technology (KAIST), 373-1 Guseong-dong, Yuseong-gu, Daejeon, 305-701, Republic of Korea, and Department of Chemistry, Columbia University, 3000 Broadway, New York, New York 10027
| | - Keliang Pang
- Molecular Logic Gate Laboratory, Department of Chemistry and School of Molecular Science -BK 21, Korea Advanced Institute of Science and Technology (KAIST), 373-1 Guseong-dong, Yuseong-gu, Daejeon, 305-701, Republic of Korea, and Department of Chemistry, Columbia University, 3000 Broadway, New York, New York 10027
| | - Snehadrinarayan Khatua
- Molecular Logic Gate Laboratory, Department of Chemistry and School of Molecular Science -BK 21, Korea Advanced Institute of Science and Technology (KAIST), 373-1 Guseong-dong, Yuseong-gu, Daejeon, 305-701, Republic of Korea, and Department of Chemistry, Columbia University, 3000 Broadway, New York, New York 10027
| | - Junseong Lee
- Molecular Logic Gate Laboratory, Department of Chemistry and School of Molecular Science -BK 21, Korea Advanced Institute of Science and Technology (KAIST), 373-1 Guseong-dong, Yuseong-gu, Daejeon, 305-701, Republic of Korea, and Department of Chemistry, Columbia University, 3000 Broadway, New York, New York 10027
| | - David G. Churchill
- Molecular Logic Gate Laboratory, Department of Chemistry and School of Molecular Science -BK 21, Korea Advanced Institute of Science and Technology (KAIST), 373-1 Guseong-dong, Yuseong-gu, Daejeon, 305-701, Republic of Korea, and Department of Chemistry, Columbia University, 3000 Broadway, New York, New York 10027
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