Subsurface alkylphenolethoxylate transformation pathways: Who's responsible and how?

ENVR 68

Martin Reinhard, reinhard@stanford.edu1, John Montgomery-Brown, jmb@stanford.edu1, Sebastian Behrens1, James A. Campbell2, and Wang-Hsien Ding, wding0224@yahoo.com.tw3. (1) Department of Civil and Environmental Engineering, Stanford University, Stanford, CA 94305-4020, (2) Box 999, MS P8-08, Pacific Northwest National Laboratory*, Battelle Blvd., Richland, WA 99352, (3) Department of Chemistry, National Central University, No. 300, Jungda Rd, Chung-Li, 32001, Taiwan
Biological attenuation of alkylphenol polyethoxylate metabolites (APEM) was studied in microcosms constructed with soil or creek sediments. The enrichment of ortho-nonylphenol (NP) and formation of branched tertiary nonyl alcohols indicated that NP was degraded via ipso-hydroxylation, a pathway only previously observed in Sphingomonads. Despite being widely distributed in aquatic and terrestrial environments, no Sphingomonads were detected in a clone library with 90 clones from the soil. A second clone library, constructed using two different Sphingomonad-specific primer combinations, also failed to find Sphingomonad sequences and suggests that bacteria other than Sphingomonads may aslo be capable of ipso-hydroxylation. Creek microcosms fed with NP1EC produced larger quantities of carboxyalkylphenol polyethocycarboxylates (CAPEC) than similarly fed soil microcosms, perhaps because the former were oxygen limited. NP1EC was transformed to para-NP, before being transformed to nonyl alcohols via ipso-hydroxylation and ortho isomers were transformed more slowly than para isomers. Novel metabolites were tentatively identified with GC-high-resolution MS and GC-MS/MS.
 

Symposium Honoring Dr. Walter Giger
8:30 AM-12:40 PM, Tuesday, August 21, 2007 Boston Park Plaza -- Stanbro Rm, Oral

Division of Environmental Chemistry

The 234th ACS National Meeting, Boston, MA, August 19-23, 2007