Author(s)

Wissal Wannoussa^1*, Thibaut Masy¹, Stéphanie D. Lambert², Benoît Heinrichs², Ludivine Tasseroul², Alaaeddin Al-Ahmad¹, Frédéric Weekers³, Philippe Thonar¹, Serge Hiligsmann¹

¹Walloon Center of Industrial Biology, Department of Chemistry and Bio-industries, University of Liège, Gembloux, Belgium.
²Laboratory of Nanomaterials, Catalysis and Electrochemistry, University of Liège, Liège, Belgium.
³Artechno S.A., Gembloux-Les Isnes, Belgium.

Nanoparticles (NP_S) are considered as a new generation of compounds to improve environmental remediation and biological processes. The aim of this study is to investigate the effect of iron NP_S encapsulated in porous silica (SiO₂) on the biphenyl biodegradation by Rhodococcus erythropolis T902.1 (RT902.1). The iron NP_S (major iron oxide Fe_xO_y form) were dispersed in the porosity of a SiO₂ support synthesized by sol-gel process. These Fe/SiO₂ NP_S offer a stimulating effect on the biodegradation rate of biphenyl, an organic pollutant that is very stable and water-insoluble. This positive impact of NP_S on the microbial biodegradation was found to be dependent on the NP_S concentration ranging from 10^-6 M to 10^-4 M. After 18 days of incubation the cultures containing NP_S at a concentration of 10^-4 M of iron improved RT902.1 growth and degraded 35% more biphenyl than those without NP_S (positive control) or with the sole SiO₂ particles. Though the microorganism could not interact directly with the insoluble iron NP_S, the results show that about 10% and 35% of the initial 10^-4 M iron NP_S encapsulated in the SiO₂ matrix would be incorporated inside or adsorbed on the cell surface respectively and 35% would be released in the supernatant. These results suggest that RT902.1 would produce siderophore-like molecules to attract iron from the porous silica matrix.

Biodegradation, Biphenyl, Rhodococcus erythropolis, Encapsulated Nanoparticles, Sol-Gel, Iron

Wannoussa, W. , Masy, T. , Lambert, S. , Heinrichs, B. , Tasseroul, L. , Al-Ahmad, A. , Weekers, F. , Thonar, P. and Hiligsmann, S. (2015) Effect of Iron Nanoparticles Synthesized by a Sol-Gel Process on Rhodococcus erythropolis T902.1 for Biphenyl Degradation. Journal of Water Resource and Protection, 7, 264-277. doi: 10.4236/jwarp.2015.73021.