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Prospecting Microbial Strains for Bioremediation and Probiotics Development for Metaorganism Research and Preservation
Published on: October 31, 2019
Recombinant carbazole-degrading strains for enhanced petroleum processing
Robert R Riddle1, Phillip R Gibbs, Richard C Willson
1Department of Biology and Biochemistry, University of Houston, Houston, TX 77204-5001, USA.
Journal of Industrial Microbiology & Biotechnology
|January 25, 2003
Summary
Biotechnological upgrading of petroleum effectively degrades carbazole, a contaminant that poisons refinery catalysts. Engineered bacteria in a two-phase system show promise for cleaner fuel production.
Area of Science:
- Biotechnology
- Petroleum Science
- Environmental Microbiology
Background:
- Petroleum stocks contain contaminants like sulfur and nitrogen compounds, reducing refining yields.
- Carbazole is a key petroleum contaminant that causes catalyst poisoning.
- Biotechnological upgrading offers a sustainable solution for processing contaminated fossil fuels.
Purpose of the Study:
- To demonstrate the biotransformation of carbazole in a liquid two-phase system.
- To investigate the effects of solvent toxicity on carbazole degradation using a solvent-resistant heterologous host.
- To explore partial carbazole transformation for retaining fuel value.
Main Methods:
- Biotransformation of carbazole in a liquid two-phase system (1-methylnaphthalene or diesel fuel).
- Expression of carbazole-transformation genes in a solvent-resistant host (P. putida Idaho).
- Testing degradation in the presence of xylenes and evaluating partial pathway transformations.
Main Results:
- Successful biotransformation of carbazole solubilized in 1-methylnaphthalene and diesel fuel.
- The recombinant P. putida Idaho strain degraded carbazole in 1-methylnaphthalene with xylenes, similar to Pseudomonas sp. LD2.
- Partial transformation yielded an intermediate retained in the oil phase, preserving carbon content.
Conclusions:
- Biotechnological upgrading of carbazole is feasible in two-phase systems.
- Solvent-resistant engineered bacteria can effectively degrade carbazole in contaminated fuels.
- Partial carbazole transformation offers potential for maintaining fuel value while reducing catalyst poisoning.
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