EAWAG’s Biocatalysis/Biodegradation Database

“The sky broke like an egg into full sunset and the water caught fire.” -- Pamela Hansford Johnson (American Critic, Author and Writer, 1912-1981)

EAWAG, the Swiss Federal Institute of Aquatic Science and Technology, offers an interesting database. Labeled Biocatalysis/Biodegradation Database, it enables a quick search for pathways to degradation on a number of substances.

For example, enter the following search string in the database’s search box …

dibenzothiophene desulfurization

… and you will see the following:

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Dibenzothiophene Desulfurization Map
This pathway was contributed by Dr. Margie Romine, Pacific Northwest National Lab, and updated by Dr. Kevin Gray, Energy BioSystems Corp., The Woodlands, TX. Jennifer Lockhart, Williams College, assisted with HTML and graphics.
This pathway is the first that purposely does not continue to intermediary metabolism. Dibenzothiophene (DBT) is a model compound for organic sulfur in fossil fuels, and its desulfurization pathway removes this sulfur (Gray et al., 1996). The EAWAG-BBD has a separate DBT degradation pathway, but in the words of Dr. Kevin Gray (personal communication, 1996):
"We know that in this species of Rhodococcus the pathway does not continue; i.e., it stops at 2-hydroxybiphenyl (HBP) and the HBP is released into the medium. The sulfur product is incorporated into cellular biomass via sulfur assimilation pathways. That actually is the beauty of this system as far as desulfurization of fossil fuels is concerned: we do not decrease the carbon content (the 'fuel value') of our substrate molecule. If all we wanted to do was degrade the dibenzothiophene (DBT) to carbon (and energy) we would have chosen an easier and more efficient enzyme system like the biphenyl or naphthalene degradation pathways (which will mineralize DBT). However we don't want to 'degrade' DBT just 'transform' it into another molecule that can then go back into the fuel while at the same time removing the sulfur. The physiological role of this enzyme system is to obtain sulfur for growth; in fact, Rhodococcus sp. IGTS8 can use dibenzothiophene as a sole source of sulfur."
The following is a text-format dibenzothiophene desulfurization pathway map. An organism which can initiate the pathway is given, but other organisms may also carry out later steps. Follow the links for more information on compounds or reactions. This is the first pathway to have its map also available in graphic (12k) format.
Page Author(s): Kevin Gray
June 30, 2014
Click this hyperlink to see the entire detailed pathway: http://eawag-bbd.ethz.ch/dbt/dbt_map.html
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TIP: Google® dibenzothiophene OR thiophene OR thiophenic and browse the results for additional interesting results.