@misc{10481/58418,
year = {2019},
month = {10},
url = {http://hdl.handle.net/10481/58418},
abstract = {The environmental conditions for the planned geological disposal of radioactive waste
—including hyper-alkaline pH, radiation or anoxia—are expected to be extremely harsh for microbial
activity. However, it is thought that microbial communities will develop in these repositories, and this
would have implications for geodisposal integrity and the control of radionuclide migration through
the surrounding environment. Nuclear waste contains radioactive isotopes of selenium (Se) such
as 79Se, which has been identified as one of the main radionuclides in a geodisposal system. Here,
we use the bacterial species Stenotrophomonas bentonitica, isolated from bentonites serving as an
artificial barrier reference material in repositories, to study the reduction of selenite (SeIV) under
simulated geodisposal conditions. This bacterium is able to reduce toxic SeIV anaerobically from a
neutral to alkaline initial pH (up to pH 10), thereby producing elemental selenium (Se0) nanospheres
and nanowires. A transformation process from amorphous Se (a-Se) nanospheres to trigonal Se
(t-Se) nanowires, through the formation of monoclinic Se (m-Se) aggregates as an intermediate step,
is proposed. The lesser solubility of Se0 and t-Se makes S. bentonitica a potential candidate to positively
influence the security of a geodisposal system, most probably with lower efficiency rates than those
obtained aerobically.},
organization = {This work was supported by the Euratom research and training programme 2014–2018 under grant
agreement no. 661880},
publisher = {MDPI},
keywords = {Stenotrophomonas bentonitica},
keywords = {Selenite},
keywords = {Reduction},
keywords = {Alkaline},
title = {The Bioreduction of Selenite under Anaerobic and Alkaline Conditions Analogous to Those Expected for a Deep Geological Repository System},
doi = {10.3390/molecules24213868},
author = {Ruiz Fresneda, Miguel Ángel and Gómez Bolívar, Jaime and Delgado Martín, Josemaría and Abad Ortega, María del Mar and Guerra Tschuschke, Isabel and Merroun, Mohamed Larbi},
}