Exploring the Mechanism of Biocatalyst Inhibition in Microbial Desulfurization
Microbial desulfurization, or biodesulfurization (BDS), of fuels is a promising technology because it can desulfurize compounds that are recalcitrant to the current standard technology in the oil industry. One of the obstacles to the commercialization of BDS is the reduction in biocatalyst activity...
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| Format: | Article |
| Language: | en_US |
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American Society for Microbiology
2014
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| Online Access: | http://hdl.handle.net/1721.1/92419 https://orcid.org/0000-0002-2046-2726 https://orcid.org/0000-0003-0437-3157 |
| _version_ | 1811086438852198400 |
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| author | Abin-Fuentes, Andres Mohamed, Magdy El-Said Wang, Daniel I. Prather, Kristala L. Jones |
| author2 | Massachusetts Institute of Technology. Department of Chemical Engineering |
| author_facet | Massachusetts Institute of Technology. Department of Chemical Engineering Abin-Fuentes, Andres Mohamed, Magdy El-Said Wang, Daniel I. Prather, Kristala L. Jones |
| author_sort | Abin-Fuentes, Andres |
| collection | MIT |
| description | Microbial desulfurization, or biodesulfurization (BDS), of fuels is a promising technology because it can desulfurize compounds that are recalcitrant to the current standard technology in the oil industry. One of the obstacles to the commercialization of BDS is the reduction in biocatalyst activity concomitant with the accumulation of the end product, 2-hydroxybiphenyl (HBP), during the process. BDS experiments were performed by incubating Rhodococcus erythropolis IGTS8 resting-cell suspensions with hexadecane at 0.50 (vol/vol) containing 10 mM dibenzothiophene. The resin Dowex Optipore SD-2 was added to the BDS experiments at resin concentrations of 0, 10, or 50 g resin/liter total volume. The HBP concentration within the cytoplasm was estimated to decrease from 1,100 to 260 μM with increasing resin concentration. Despite this finding, productivity did not increase with the resin concentration. This led us to focus on the susceptibility of the desulfurization enzymes toward HBP. Dose-response experiments were performed to identify major inhibitory interactions in the most common BDS pathway, the 4S pathway. HBP was responsible for three of the four major inhibitory interactions identified. The concentrations of HBP that led to a 50% reduction in the enzymes' activities (IC[subscript 50]s) for DszA, DszB, and DszC were measured to be 60 ± 5 μM, 110 ± 10 μM, and 50 ± 5 μM, respectively. The fact that the IC[subscript 50]s for HBP are all significantly lower than the cytoplasmic HBP concentration suggests that the inhibition of the desulfurization enzymes by HBP is responsible for the observed reduction in biocatalyst activity concomitant with HBP generation. |
| first_indexed | 2024-09-23T13:25:56Z |
| format | Article |
| id | mit-1721.1/92419 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T13:25:56Z |
| publishDate | 2014 |
| publisher | American Society for Microbiology |
| record_format | dspace |
| spelling | mit-1721.1/924192022-09-28T14:09:42Z Exploring the Mechanism of Biocatalyst Inhibition in Microbial Desulfurization Abin-Fuentes, Andres Mohamed, Magdy El-Said Wang, Daniel I. Prather, Kristala L. Jones Massachusetts Institute of Technology. Department of Chemical Engineering Prather, Kristala L. Jones Abin-Fuentes, Andres Wang, Daniel I. Prather, Kristala L. Jones Microbial desulfurization, or biodesulfurization (BDS), of fuels is a promising technology because it can desulfurize compounds that are recalcitrant to the current standard technology in the oil industry. One of the obstacles to the commercialization of BDS is the reduction in biocatalyst activity concomitant with the accumulation of the end product, 2-hydroxybiphenyl (HBP), during the process. BDS experiments were performed by incubating Rhodococcus erythropolis IGTS8 resting-cell suspensions with hexadecane at 0.50 (vol/vol) containing 10 mM dibenzothiophene. The resin Dowex Optipore SD-2 was added to the BDS experiments at resin concentrations of 0, 10, or 50 g resin/liter total volume. The HBP concentration within the cytoplasm was estimated to decrease from 1,100 to 260 μM with increasing resin concentration. Despite this finding, productivity did not increase with the resin concentration. This led us to focus on the susceptibility of the desulfurization enzymes toward HBP. Dose-response experiments were performed to identify major inhibitory interactions in the most common BDS pathway, the 4S pathway. HBP was responsible for three of the four major inhibitory interactions identified. The concentrations of HBP that led to a 50% reduction in the enzymes' activities (IC[subscript 50]s) for DszA, DszB, and DszC were measured to be 60 ± 5 μM, 110 ± 10 μM, and 50 ± 5 μM, respectively. The fact that the IC[subscript 50]s for HBP are all significantly lower than the cytoplasmic HBP concentration suggests that the inhibition of the desulfurization enzymes by HBP is responsible for the observed reduction in biocatalyst activity concomitant with HBP generation. National Institutes of Health (U.S.). Biotechnology Training Program 2014-12-19T20:28:07Z 2014-12-19T20:28:07Z 2013-10 2013-08 Article http://purl.org/eprint/type/JournalArticle 0099-2240 1098-5336 http://hdl.handle.net/1721.1/92419 Abin-Fuentes, A., M. E.-S. Mohamed, D. I. C. Wang, and K. L. J. Prather. “Exploring the Mechanism of Biocatalyst Inhibition in Microbial Desulfurization.” Applied and Environmental Microbiology 79, no. 24 (October 4, 2013): 7807–7817. https://orcid.org/0000-0002-2046-2726 https://orcid.org/0000-0003-0437-3157 en_US http://dx.doi.org/10.1128/aem.02696-13 Applied and Environmental Microbiology Creative Commons Attribution-Noncommercial-Share Alike http://creativecommons.org/licenses/by-nc-sa/4.0/ application/pdf American Society for Microbiology Prof. Prather via Erja Kajosalo |
| spellingShingle | Abin-Fuentes, Andres Mohamed, Magdy El-Said Wang, Daniel I. Prather, Kristala L. Jones Exploring the Mechanism of Biocatalyst Inhibition in Microbial Desulfurization |
| title | Exploring the Mechanism of Biocatalyst Inhibition in Microbial Desulfurization |
| title_full | Exploring the Mechanism of Biocatalyst Inhibition in Microbial Desulfurization |
| title_fullStr | Exploring the Mechanism of Biocatalyst Inhibition in Microbial Desulfurization |
| title_full_unstemmed | Exploring the Mechanism of Biocatalyst Inhibition in Microbial Desulfurization |
| title_short | Exploring the Mechanism of Biocatalyst Inhibition in Microbial Desulfurization |
| title_sort | exploring the mechanism of biocatalyst inhibition in microbial desulfurization |
| url | http://hdl.handle.net/1721.1/92419 https://orcid.org/0000-0002-2046-2726 https://orcid.org/0000-0003-0437-3157 |
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