Anaerobic 1-Alkene Metabolism by the Alkane- and Alkene-Degrading Sulfate Reducer Desulfatibacillum aliphaticivorans Strain CV2803 ^T

Abstract

The alkane-and alkene-degrading, marine sulfate-reducing bacterium Desulfatibacillum aliphaticivorans strain CV2803T , known to oxidize n-alkanes anaerobically by fumarate addition at C-2, was investigated for its 1-alkene metabolism. The total cellular fatty acids of this strain were predominantly C-(even number) (C-even) when it was grown on C-even 1-alkenes and predominantly C-(odd number) (C-odd) when it was grown on C-odd 1-alkenes. Detailed analyses of those fatty acids by gas chromatography-mass spectrometry after 6-to 10-week incubations allowed the identification of saturated 2-and 4-ethyl-, 2-and 4-methyl-, and monounsat-

Anaerobic Oxidation of Fatty Acids and Alkenes by the Hyperthermophilic Sulfate-Reducing Archaeon Archaeoglobus fulgidus

“…However, the loss of three deuterium atoms between the alkene substrate and the corresponding fatty acid (Fig. 3b) is not in agreement with the results obtained with D. aliphaticivorans strain CV2803, which induced the loss of only two deuterium atoms for the same oxidation step (14). The present results may be explained either by hydrogen/deuterium exchanges at high temperature and/or by distinct mechanisms of alk-1-ene oxidation between The formation of C-even and C-odd fatty acids from C-odd and C-even alkanes, respectively, has been demonstrated in the mesophilic sulfate-reducing bacterium strain Hxd3 (24).…”

“…fulgidus was grown in 450 ml of anoxic medium with labeled hexadecene (perdeuterated d 32 -hexadec-1-ene, 0.55 mM, synthesized from perdeuterated palmitic acid [Eurisotop] as described by Grossi et al [14]). Cells were collected by filtration through glass microfiber filters (GF/B; Whatman) and treated with 1 M KOH in methanol-water (1:1 [vol/vol]).…”

“…To our knowledge, this is the first report of the anaerobic oxidation of hydrocarbons, specifically n-alkenes, by a member of the domain Archaea and at a temperature as high as 70°C. Different initial reactions of anaerobic alk-1-ene oxidation by D. aliphaticivorans strain CV2803 have been proposed (14). This bacterium oxidized alkenes into either branched (methyl-or ethyl-) or linear fatty acids by addition of organic carbon or by hydroxylation of the double bond, respectively.…”

“…3c). Alternative mechanisms can be envisaged for the oxidation of alk-1-enes by strain VC-16, including the addition of an organic carbon unit distinct from the one involved in alk-1-ene oxidation by D. aliphaticivorans strain CV2803 (14) or the epoxidation of the (17) isolated and characterized a Mo-Fe-S-containing enzyme from Azoarcus sp. strain EB1 that was able to mediate, in the absence of oxygen, the hydroxylation of a branched alkene.…”

Mono- and Dialkyl Glycerol Ether Lipids in Anaerobic Bacteria: Biosynthetic Insights from the Mesophilic Sulfate Reducer Desulfatibacillum alkenivorans PF2803 T

“…Unlabeled alkenes (pentadec-1-ene and hexadec-1-ene, Ͼ99% pure) and 2,2-D 2 -hexadecanoic acid were purchased from Aldrich Chemical Co. 1-D 2 -pentadec-1-ene and perdeuterated hexadec-1-ene (D 32 -hexadec-1-ene) were synthesized in three steps from unlabeled pentadecanoic acid (Aldrich) and perdeuterated palmitic acid (C 15 D 31 COOH; Euriso-top), respectively, as described previously (38 T was isolated from marine sediment (Fos Harbor, Mediterranean Sea, France [39]). It belongs to the family Desulfobacteraceae in the Deltaproteobacteria (see Fig.…”