Methyl Selenol as a Precursor in Selenite Reduction to Se/S Species by Methane-Oxidizing Bacteria
Metadata
Show full item recordEditorial
American Society for Microbiology
Materia
Selenite reduction Elemental selenium Methane-oxidizing bacteria Mixed chalcogenide amorphous nanoparticles
Date
2019-10-30Referencia bibliográfica
Eswayah AS, Hondow N, Scheinost AC, Merroun M, Romero-González M, Smith TJ, Gardiner PHE. 2019. Methyl selenol as a precursor in selenite reduction to Se/S species by methane-oxidizing bacteria. Appl Environ Microbiol 85:e01379-19.
Abstract
A wide range of microorganisms have been shown to transform seleniumcontaining
oxyanions to reduced forms of the element, particularly seleniumcontaining
nanoparticles. Such reactions are promising for the detoxification of environmental
contamination and the production of valuable selenium-containing products,
such as nanoparticles for application in biotechnology. It has previously been shown
that aerobic methane-oxidizing bacteria, including Methylococcus capsulatus (Bath),
are able to perform the methane-driven conversion of selenite (SeO3
2-) to seleniumcontaining
nanoparticles and methylated selenium species. Here, the biotransformation
of selenite by Mc. capsulatus (Bath) has been studied in detail via a range of imaging,
chromatographic, and spectroscopic techniques. The results indicate that the
nanoparticles are produced extracellularly and have a composition distinct from that
of nanoparticles previously observed from other organisms. The spectroscopic data
from the methanotroph-derived nanoparticles are best accounted for by a bulk
structure composed primarily of octameric rings in the form Se8 - xSx with an outer
coat of cell-derived biomacromolecules. Among a range of volatile methylated selenium
and selenium-sulfur species detected, methyl selenol (CH3SeH) was found only
when selenite was the starting material, although selenium nanoparticles (both biogenic
and chemically produced) could be transformed into other methylated selenium
species. This result is consistent with methyl selenol being an intermediate in
the methanotroph-mediated biotransformation of selenium to all the methylated
and particulate products observed.