Metabolism of a nonylphenol isomer by Sphingomonas sp. strain TTNP3

For elucidation of the metabolism of the endocrine disruptor nonylphenol by Sphingomonas sp. strain TTNP3, the degradation of an isomer of nonylphenol, 4(2′,6′-dimethyl-2′-heptyl)-phenol, has been studied. As in the case of 4(3′,5′-dimethyl-3′-heptyl)-phenol, the metabolism of this nonylphenol isomer leads to the formation of the NIH-shifted product 2(2′,6′-dimethyl-2′-heptyl)-1,4-benzenediol (NIH: National Institute of Health), but also to the alkoxy derivative 4(2′,6′-dimethylheptan-2′-yloxy)phenol as additional metabolite. To the best of our knowledge, this is the first report describing the formation of alkoxyphenol as a degradation product of nonylphenol. Additionally, these results provide for the first time evidence for slight differences in the biodegradation of the isomers of nonylphenol.