Table of Contents
ISRN Microbiology
Volume 2013, Article ID 284950, 9 pages
Research Article

Biodegradation of Polyethoxylated Nonylphenols

1Centro de Investigaciones Microbiológicas Aplicadas (CIMA), Facultad de Ciencias de la Salud, Universidad de Carabobo, Valencia 2005, Venezuela
2Centro de Investigaciones Químicas (CIQ), Facultad de Ingeniería, Universidad de Carabobo, Valencia 2005, Venezuela
3Departamento de Química, Facultad de Ciencias y Tecnología (FACYT), Universidad de Carabobo, Bárbula 2001, Naguanagua 2005, Carabobo, Venezuela

Received 14 May 2013; Accepted 4 June 2013

Academic Editors: P. Di Martino and T. P. West

Copyright © 2013 Yassellis Ruiz et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Polyethoxylated nonylphenols, with different ethoxylation degrees ( ), are incorporated into many commercial and industrial products such as detergents, domestic disinfectants, emulsifiers, cosmetics, and pesticides. However, the toxic effects exerted by their degradation products, which are persistent in natural environments, have been demonstrated in several animal and invertebrate aquatic species. Therefore, it seems appropriate to look for indigenous bacteria capable of degrading native and its derivatives. In this paper, the isolation of five bacterial strains, capable of using , as unique carbon source, is described. The most efficient degrader bacterial strains were identified as Pseudomonas fluorescens (strain Yas2) and Klebsiella pneumoniae (strain Yas1). Maximal growth rates were reached at pH 8, 27°C in a 5% medium. The degradation extension, followed by viscometry assays, reached 65% after 54.5 h and 134 h incubation times, while the COD values decreased by 95% and 85% after 24 h for the Yas1 and Yas2 systems, respectively. The BOD was reduced by 99% and 99.9% levels in 24 h and 48 h incubations. The viscosity data indicated that the biodegradation by Yas2 follows first-order kinetics. Kinetic rate constant ( ) and half life time ( ) for this biotransformation were estimated to be 0.0072 h−1 and 96.3 h, respectively.