A. V. Callaghan, M. Tierney, C. Phelps
Dec 29, 2008
Citations
3
Influential Citations
75
Citations
Quality indicators
Journal
Applied and Environmental Microbiology
Abstract
ABSTRACT Nitrate-reducing enrichments, amended with n-hexadecane, were established with petroleum-contaminated sediment from Onondaga Lake. Cultures were serially diluted to yield a sediment-free consortium. Clone libraries and denaturing gradient gel electrophoresis analysis of 16S rRNA gene community PCR products indicated the presence of uncultured alpha- and betaproteobacteria similar to those detected in contaminated, denitrifying environments. Cultures were incubated with H34-hexadecane, fully deuterated hexadecane (d34-hexadecane), or H34-hexadecane and NaH13CO3. Gas chromatography-mass spectrometry analysis of silylated metabolites resulted in the identification of [H29]pentadecanoic acid, [H25]tridecanoic acid, [1-13C]pentadecanoic acid, [3-13C]heptadecanoic acid, [3-13C]10-methylheptadecanoic acid, and d27-pentadecanoic, d25-, and d24-tridecanoic acids. The identification of these metabolites suggests a carbon addition at the C-3 position of hexadecane, with subsequent β-oxidation and transformation reactions (chain elongation and C-10 methylation) that predominantly produce fatty acids with odd numbers of carbons. Mineralization of [1-14C]hexadecane was demonstrated based on the recovery of 14CO2 in active cultures.