<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="6.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Videla, P. P.</style></author><author><style face="normal" font="default" size="100%">Farwell, A. J.</style></author><author><style face="normal" font="default" size="100%">Butler, B. J.</style></author><author><style face="normal" font="default" size="100%">Dixon, D. G.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Examining the microbial degradation of naphthenic acids using stable isotope analysis of carbon and nitrogen</style></title></titles><keywords><keyword><style  face="normal" font="default" size="100%">analytical methodology</style></keyword><keyword><style  face="normal" font="default" size="100%">Biodegradation</style></keyword><keyword><style  face="normal" font="default" size="100%">bioremediation</style></keyword><keyword><style  face="normal" font="default" size="100%">microbiology</style></keyword><keyword><style  face="normal" font="default" size="100%">naphthenic acids</style></keyword><keyword><style  face="normal" font="default" size="100%">nitrogen</style></keyword><keyword><style  face="normal" font="default" size="100%">NOx</style></keyword><keyword><style  face="normal" font="default" size="100%">tailings water</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2009</style></year></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://search.proquest.com/docview/208172225</style></url></web-urls></urls><publisher><style face="normal" font="default" size="100%">Water Air &amp; Soil Pollution </style></publisher><volume><style face="normal" font="default" size="100%">197</style></volume><pages><style face="normal" font="default" size="100%">12 pages </style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">Naphthenic acids (NAs) are a complex group of naturally occurring oil sands constituents that constitute a significant portion of the dissolved organic carbon (DOC) pool available for microbial degradation in the process-related waste water associated with oil sands mine sites. One approach to understanding the biological fate of oil sands process-derived carbon and nitrogen in aquatic reclamation of the mine sites involves the use of stable isotope analyses. However, for stable isotope analyses to be useful in such field-based assessments, there is a need to determine how microbial degradation of a complex mixture of NAs might change the stable isotope values (δ 13C, δ 15N). In batch cultures and semi-continuous laboratory microcosms, utilization of a commercial mixture of NAs by oil sands-derived microbial cultures resulted in microbial biomass that was similar or slightly 13C enriched (1.4[per thousand] to 3.0[per thousand]) relative to the DOC source, depending on the length of incubation. Utilization of a NA-containing extract of oil sands processed water resulted in greater 13C enrichment of microbial biomass (8.5[per thousand]) relative to the DOC source. Overall, the δ13C of the DOC comprised of complex mixtures of NAs showed minimal change (-0.5[per thousand] to -0.1[per thousand]) during the incubation period whereas the δ13C of the dissolved inorganic carbon (DIC) was more variable (-5.0[per thousand] to +5.4[per thousand]). In tests where the concentration of available nitrogen was increased, the final biomass values were 15N enriched (3.8[per thousand] to 8.4[per thousand]) relative to the initial biomass. The isotope trends established in this study should enhance our ability to interpret field-based data from sites with hydrocarbon contamination, particularly in terms of carbon source utilization and 15N enrichment.</style></abstract><issue><style face="normal" font="default" size="100%">1-4</style></issue><custom3><style face="normal" font="default" size="100%">http://www.worldcat.org/oclc/438984437</style></custom3><custom4><style face="normal" font="default" size="100%">OSEMB</style></custom4></record></records></xml>