Free access
1 April 1996

Isolation and characterization of a novel toluene-degrading, sulfate-reducing bacterium


A novel sulfate-reducing bacterium isolated from fuel-contaminated subsurface soil, strain PRTOL1, mineralizes toluene as the sole electron donor and carbon source under strictly anaerobic conditions. The mineralization of 80% of toluene carbon to CO2 was demonstrated in experiments with [ring-U-14C]toluene; 15% of toluene carbon was converted to biomass and nonvolatile metabolic by-products, primarily the former. The observed stoichiometric ratio of moles of sulfate consumed per mole of toluene consumed was consistent with the theoretical ratio for mineralization of toluene coupled with the reduction of sulfate to hydrogen sulfide. Strain PRTOL1 also transforms o- and p-xylene to metabolic products when grown with toluene. However, xylene transformation by PRTOL1 is slow relative to toluene degradation and cannot be sustained over time. Stable isotope-labeled substrates were used in conjunction with gas chromatography-mass spectrometry to investigate the by-products of toluene and xylene metabolism. The predominant by-products from toluene, o-xylene, and p-xylene were benzylsuccinic acid, (2-methylbenzyl)succinic acid, and 4-methylbenzoic acid (or p-toluic acid), respectively. Metabolic by-products accounted for nearly all of the o-xylene consumed. Enzyme assays indicated that acetyl coenzyme A oxidation proceeded via the carbon monoxide dehydrogenase pathway. Compared with the only other reported toluene-degrading, sulfate-reducing bacterium, strain PRTOL1 is distinct in that it has a novel 16S rRNA gene sequence and was derived from a freshwater rather than marine environment.

Formats available

You can view the full content in the following formats:

Information & Contributors


Published In

cover image Applied and Environmental Microbiology
Applied and Environmental Microbiology
Volume 62Number 4April 1996
Pages: 1188 - 1196
PubMed: 8919780


Published online: 1 April 1996


Request permissions for this article.



H R Beller
Department of Civil Engineering, Stanford University, California 94305-4020, USA.
A M Spormann
Department of Civil Engineering, Stanford University, California 94305-4020, USA.
P K Sharma
Department of Civil Engineering, Stanford University, California 94305-4020, USA.
J R Cole
Department of Civil Engineering, Stanford University, California 94305-4020, USA.
M Reinhard
Department of Civil Engineering, Stanford University, California 94305-4020, USA.

Metrics & Citations




If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.

View Options

View options



Get Access

Non-Member Login
Buy Article
Applied and Environmental Microbiology Vol.62 • Issue 4 • ASM Journals Pay Per View, PPV 25
Journal Subscription
Applied and Environmental Microbiology
ASM members can purchase subscriptions to journals.
Join or renew

Restore your content access

Enter your email address to restore your content access:

Note: This functionality works only for purchases done as a guest. If you already have an account, log in to access the content to which you are entitled.

Figures and Media






Share the article link

Share with email

Email a colleague

Share on social media

American Society for Microbiology ("ASM") is committed to maintaining your confidence and trust with respect to the information we collect from you on websites owned and operated by ASM ("ASM Web Sites") and other sources. This Privacy Policy sets forth the information we collect about you, how we use this information and the choices you have about how we use such information.
FIND OUT MORE about the privacy policy