Development of eukaryotic zoospores within polycyclic aromatic hydrocarbon (PAH)-polluted environments: A set of behaviors that are relevant for bioremediation

10 páginas.-- 5 figuras.-- 2 tablas.-- 41 referencias.-- Supplementary data to this article can be found online at http://dx. doi.org/10.1016/j.scitotenv.2014.12.089. http://www.sciencedirect.com/science/article/pii/.

© 2014 Elsevier B.V. In this study, we assessed the development (formation, taxis and settlement) of eukaryotic zoospores under different regimes of exposure to polycyclic aromatic hydrocarbons (PAHs), which imitated environmental scenarios of pollution and bioremediation. With this aim, we used an oomycete, Pythium aphanidermatum, as a source of zoospores and two PAH-degrading bacteria (Mycobacterium gilvum VM552 and Pseudomonas putida G7). The oomycete and both bacteria were not antagonistic, and zoospore formation was diminished only in the presence of the highest bacterial cell density (108-1010colony-formingunitsmL-1). A negative influence of PAHs on zoospore formation and taxis was observed when PAHs were exposed in combination with organic solutions and polar solvents. Co-exposure of PAHs with non-polar solvents [hexadecane (HD) and 2,2,4,4,6,8,8-heptamethylnonane (HMN)] did not affect zoospore settlement at the interfaces of the organic solvents and water. However, zoospores settled and created mycelial networks only at HD-water interfaces. Both bacteria diminished the toxic influence of PAHs on zoospore formation and taxis, and they did not interrupt zoospore settlement. The results suggest that zoospore development could be applicable for toxicity assessment of PAHs and enhancement of their bioavailability. Microbial interactions during both swimming modes and community formation at pollutant interfaces were revealed as major factors that have potential relevance to bioremediation.

Support for this research was provided by the Spanish Ministry of Science and Innovation (CGL2010-22068-C02-01 and CGL2013-44554-R), the Andalusian Government (RNM 2337) and the CSIC JAE Programme (RS). PvW has funding support from the BBSRC and NERC. We are grateful to Dr. Herbert van den Berg (Aberdeen Oomycete Laboratory, University of Aberdeen) for preparing the initial stock of Py. aphanidermatum and delivering it to us and Dr. Fredrik Heyman (Uppsala BioCenter, Swedish University of Agricultural Sciences) for his guidance regarding production of oomycete zoospores.

Peer Reviewed