Show simple item record

dc.contributor.authorRontani, J-F.
dc.contributor.authorHarji, R.
dc.contributor.authorGuasco, S.
dc.contributor.authorPrahl, F.G.
dc.contributor.authorVolkman, J.K.
dc.contributor.authorBhosle, N.B.
dc.contributor.authorBonin, P.
dc.date.accessioned2008-03-27T11:27:48Z
dc.date.available2008-03-27T11:27:48Z
dc.date.issued2008
dc.identifier.citationOrganic Geochemistry, vol.39(1); 34-51p.
dc.identifier.urihttp://drs.nio.org/drs/handle/2264/1034
dc.description.abstractFour bacterial communities were isolated from Emiliania huxleyi strain TWP1 cultures before and after the algal cells had been treated with different antibiotics. Incubation of E. huxleyi with these bacterial communities resulted in dramatically different extents of alkenone degradation, ranging from effectively none to extensive. Selective degradation of the more unsaturated alkenones was observed in experiments using the total bacterial community and one of the communities isolated from antibiotic-treated algal cells. The observed increases in U sup (k’) sub(37) are equivalent to a +2 degrees C and +3.3 degrees C change in the inferred temperature. Our results clearly show that intense aerobic microbial degradative processes have the potential to introduce a significant ‘warm’ bias in palaeotemperature reconstruction and could explain apparent anomalies in palaeotemperatures inferred from alkenone distributions in strongly oxidizing sedimentary environments. The results show that aerobic bacteria capable of selectively degrading alkenones are not limited to particular environments such as microbial mats and can be actually associated with living E. huxleyi cells. The detection of epoxyketones in some cultures indicates that metabolic pathways involving attack at the terminal groups of the molecule are essentially non-selective, while those acting on alkenone double bonds are selective. The epoxyketones resulting from bacterial epoxidation of alkenone double bonds could be useful indicators of aerobic bacterial alteration of the alkenone unsaturation ratio in situ. The production of alkenols during incubation with one of the bacterial communities demonstrated for the first time that bacterial reduction of alkenones can be a potential source of these compounds in the environment. The intriguing production of small amounts of monounsaturated alkenones by one of the bacterial communities also raises the possibility of a bacterial reduction of alkenone double bonds.
dc.language.isoen
dc.publisherElsevier
dc.rightsCopyright [2008] Elsevier
dc.subjectalkenone degradation
dc.subjectbacterial community
dc.subjectmicrobial mats
dc.subjectmonounsaturated alkenones
dc.titleDegradation of alkenones by aerobic heterotrophic bacteria: Selective or not ?
dc.typeJournal Article


Files in this item

Thumbnail
Thumbnail

This item appears in the following Collection(s)

Show simple item record