TitleFormation of Developmentally Toxic Phenanthrene Metabolite Mixtures by Mycobacterium sp. ELW1.
Publication TypeJournal Article
Year of Publication2017
AuthorsSchrlau, JE, Kramer, AL, Chlebowski, AC, Truong, L, Tanguay, RL, Simonich, SLMassey, Semprini, L
JournalEnviron Sci Technol
Date Published2017 Aug 01
KeywordsAnimals, Mycobacterium, Phenanthrenes, Water Pollutants, Chemical, Zebrafish

Mycobacterium sp. ELW1 co-metabolically degraded up to 1.8 μmol of phenanthrene (PHE) in ∼48 h, and hydroxyphenanthrene (OHPHE) metabolites, including 1-hydroxyphenanthrene (1-OHPHE), 3-hydroxyphenanthrene (3-OHPHE), 4-hydroxyphenanthrene (4-OHPHE), 9-hydroxyphenanthrene (9-OHPHE), 9,10-dihydroxyphenanthrene (1,9-OHPHE), and trans-9,10-dihydroxy-9,10-dihydrophenanthrene (trans-9,10-OHPHE), were identified and quantified over time. The monooxygenase responsible for co-metabolic transformation of PHE was inhibited by 1-octyne. First-order PHE transformation rates, k, and half-lives, t, for PHE-exposed cells were 0.16-0.51 h and 1.4-4.3 h, respectively, and the 1-octyne controls ranged from 0.015-0.10 h to 7.0-47 h, respectively. While single compound standards of PHE and trans-9,10-OHPHE, the major OHPHE metabolite formed by ELW1, were not toxic to embryonic zebrafish (Danio rerio), single compound standards of minor OHPHE metabolites, 1-OHPHE, 3-OHPHE, 4-OHPHE, 9-OHPHE, and 1,9-OHPHE, were toxic, with effective concentrations (EC's) ranging from 0.5 to 5.5 μM. The metabolite mixtures formed by ELW1, and the reconstructed standard mixtures of the identified OHPHE metabolites, elicited a toxic response in zebrafish for the same three time points. ECs for the metabolite mixtures formed by ELW1 were lower (more toxic) than those for the reconstructed standard mixtures of the identified OHPHE metabolites. Ten unidentified hydroxy PHE metabolites were measured in the derivatized mixtures formed by ELW1 and may explain the increased toxicity of the ELW1 metabolites mixture relative to the reconstructed standard mixtures of the identified OHPHE metabolites.

Alternate JournalEnviron. Sci. Technol.
PubMed ID28727453
PubMed Central IDPMC5996983
Grant ListP30 ES000210 / ES / NIEHS NIH HHS / United States
P42 ES016465 / ES / NIEHS NIH HHS / United States