TITLE:
Effect of Iron Nanoparticles Synthesized by a Sol-Gel Process on Rhodococcus erythropolis T902.1 for Biphenyl Degradation
AUTHORS:
Wissal Wannoussa, Thibaut Masy, Stéphanie D. Lambert, Benoît Heinrichs, Ludivine Tasseroul, Alaaeddin Al-Ahmad, Frédéric Weekers, Philippe Thonar, Serge Hiligsmann
KEYWORDS:
Biodegradation, Biphenyl, Rhodococcus erythropolis, Encapsulated Nanoparticles, Sol-Gel, Iron
JOURNAL NAME:
Journal of Water Resource and Protection,
Vol.7 No.3,
February
27,
2015
ABSTRACT: Nanoparticles
(NPS) 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 NPS encapsulated in porous silica
(SiO2) on the biphenyl biodegradation by Rhodococcus erythropolis T902.1 (RT902.1). The iron NPS (major iron oxide FexOy form) were dispersed in the porosity of a SiO2 support synthesized
by sol-gel process. These Fe/SiO2 NPS offer a stimulating
effect on the biodegradation rate of biphenyl, an organic pollutant that is
very stable and water-insoluble. This positive impact of NPS on the
microbial biodegradation was found to be dependent on the NPS concentration ranging from 10-6 M to 10-4 M. After 18
days of incubation the cultures containing NPS at a concentration of
10-4 M of iron improved RT902.1 growth and degraded 35% more
biphenyl than those without NPS (positive control) or with the sole
SiO2 particles. Though the microorganism could not interact directly
with the insoluble iron NPS, the results show that about 10% and 35%
of the initial 10-4 M iron NPS 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.