Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published December 2013 | Supplemental Material
Journal Article Open

Anaerobic biodegradation of the isoprenoid biomarkers pristane and phytane


Isoprenoids, a diverse class of compounds synthesized by all three domains of life, comprise many of the biomarker compounds used in paleoenvironmental and paleoecological reconstruction of Earth history. These biomarkers include hopanoids, sterols and archaeal membrane lipids. While changes in hydrocarbon profiles in anoxic sediments and oilfields indicate that anaerobic microbial metabolism is involved in the disappearance or alteration of isoprenoids, direct links between specific compounds and their microbial degraders are lacking. Here we describe pristane (Pr) and phytane (Ph) degradation associated with NO^-_3 reduction. We confirmed isoprenoid conversion to CO_2 using ^(13)C-labeled Ph. After 120 days, dissolved inorganic carbon (DIC) produced in incubations grown with ^(13)C-labeled Ph had a δ^(13)C value of +76.7 ± 11.9‰, significantly higher than values for incubations with unlabeled Ph (−35.7 ± 2.0‰) and those without an added carbon substrate (−30.0 ± 2.1‰). Additional incubations, displayed NO^-_3 reduction after amendment with archaeal diphytanyl glycerol diether (DGD) core lipids, but not in those amended with glycerol diphytanyl glycerol tetraether (GDGT) core lipids. Both 16S rRNA clone libraries and whole cell rRNA-targeted fluorescent in situ hybridization (FISH) indicated that the likely Pr and Ph degrading Bacteria were Gamma proteobacteria, with > 99% similarity to Pseudomonas stutzeri.

Additional Information

© 2013 Elsevier Ltd. Received 26 June 2013. Received in revised form 27 September 2013. Accepted 16 October 2013. Available online 22 October 2013. The research was supported by a grant from American Chemical Society Petroleum Research Fund to J.L.M. (48445-AC2) the Penn State Biogeochemical Research Initiative for Education (BRIE) (NSF DGE-9972759), the Penn State Astrobiology Research Center (PSARC), NASA NAI (NNA04CC06A) and a Penn State Biogeochemistry Program fellowship to K.S.D. We thank L. Krumholz for providing a culture of Haloferax sulfurifontis and Z. Zhang and D. Walizer for technical assistance. We also thank C.H. House, J.M. Regan and two anonymous reviewers for valuable discussions and comments towards improving the paper. Associate Editor: S. Schouten.

Attached Files

Supplemental Material - mmc1.docx


Files (272.2 kB)
Name Size Download all
272.2 kB Download

Additional details

August 19, 2023
October 25, 2023