Metabolic pathway of xenoestrogenic short ethoxy chain-nonylphenol to nonylphenol by aerobic bacteria, Ensifer sp. strain AS08 and Pseudomonas sp. strain AS90.
Ensifer sp. strain AS08 and Pseudomonas sp. strain AS90 degrading short ethoxy (EO) chain-nonylphenol (NP) [NPEO(av2.0) containing NP mono- approximately tetraethoxylates (NP1EO approximately NP4EO); average 2.0 EO units] were isolated by enrichment cultures. Both strains grew on NP but not on octyl- and nonylphenol polyethoxylates (NPEOs) (average 10 EO units). Growth and degradation of NPEO(av2.0) was increased with increased concentrations of yeast extract (0.02-0.5%) in a culture medium. Culture supernatants of both strains grown on NPEO(av2.0) were analyzed by high-performance liquid chromatography, showing degradation of NP4EO-NP1EO. The metabolites from nonylphenol diethoxylate (NP2EO) by resting cells of both strains were identified by gas chromatography-mass spectrometry as nonylphenoxyethoxyacetic acid, NP1EO, nonylphenoxyacetic acid (NP1EC), and NP, while those from NP1EO were identified as NP1EC and NP. Cell-free extracts from strain AS08 grown on NPEO(av2.0) dehydrogenated NPEOs, NPEO(av2.0), NP2EO, NP1EO, and PEG 400, but the extracts were inactive toward di- approximately tetraethylene glycol. Aldehydes were formed in the reaction mixture of each substrate with cell-free extracts. From these results, the aerobic metabolic pathway for short EO chain-NP is proposed: A terminal alcohol group of the EO chain is oxidized to a carboxylic acid via an aldehyde, and then one EO unit is removed. This process is repeated until NP is produced.
Liu
Xin
X
Laboratory of Applied Microbiology, Research Institute for Bioresources, Okayama University, Kurashiki, 2-20-1 Chuo, Kurashiki 710-0046, Japan.
Tani
Akio
A
Kimbara
Kazuhide
K
Kawai
Fusako
F
D001673:Biodegradation, Environmental; D004785:Environmental Pollutants / Q000378:metabolism; D004968:Estrogens, Non-Steroidal / Q000378:metabolism*; D005026:Ethylene Glycols / Q000378:metabolism*; D011549:Pseudomonas / Q000302:isolation & purification / Q000378:metabolism*; D012230:Rhizobiaceae / Q000302:isolation & purification / Q000378:metabolism*; D012722:Sewage / Q000382:microbiology*
D004785:Environmental Pollutants; D004968:Estrogens, Non-Steroidal; D005026:Ethylene Glycols; D012722:Sewage; C021754:terics