4 research outputs found
Quantification, Localization, and Speciation of Selenium in Seeds of Canola and Two Mustard Species Compared to Seed-Meals Produced by Hydraulic Press
<i>Brassica</i> plants accumulate selenium
(Se) especially
in seeds when grown in soils laden with Se. We report a chemical analysis
of Se in <i>Brassica</i> seeds (canola, Indian mustard,
and white mustard) and in their hydraulically pressed seed meals,
which are used as a Se supplement in livestock animal feeds. Complementary
techniques were used to measure total Se concentrations, to map the
localization of Se, and to quantify different Se forms. Seeds and
hydraulically pressed seed meals contained an average of 1.8 and 2.0
μg Se g<sup>–1</sup> DW, respectively. Selenium was primarily
located in cotyledons and roots of seed embryos. Microfocused Se K-edge
XANES and bulk XANES showed that seeds contained 90% of Se as C–Se–C
forms. Hydraulically pressing seeds for oil caused changes in the
forms of Se as follows: 40–55% C–Se–C forms,
33–42% selenocystine, 5–12% selenocysteine, and 11–14%
trimethylselenonium ion. Aqueous extracts of seed and seed meals were
also analyzed by SAX-HPLC/ICPMS and found to contain mainly the C–Se–C
form SeMet, but also another C–Se–C form MeSeCys, which
is of dietary pharmacological interest for cancer inhibition. In addition,
SAX-HPLC/ICPMS also detected selenocystine and selenocysteine, further
confirming the results obtained by XANES analyses
Selenium Biotransformations in an Engineered Aquatic Ecosystem for Bioremediation of Agricultural Wastewater via Brine Shrimp Production
An
engineered aquatic ecosystem was specifically designed to bioremediate
selenium (Se), occurring as oxidized inorganic selenate from hypersalinized
agricultural drainage water while producing brine shrimp enriched
in organic Se and omega-3 and omega-6 fatty acids for use in value
added nutraceutical food supplements. Selenate was successfully bioremediated
by microalgal metabolism into organic Se (seleno-amino acids) and
partially removed via gaseous volatile Se formation. Furthermore,
filter-feeding brine shrimp that accumulated this organic Se were
removed by net harvest. Thriving in this engineered pond system, brine
shrimp (Artemia franciscana Kellogg)
and brine fly (Ephydridae sp.) have
major ecological relevance as important food sources for large populations
of waterfowl, breeding, and migratory shore birds. This aquatic ecosystem
was an ideal model for study because it mimics trophic interactions
in a Se polluted wetland. Inorganic selenate in drainage water was
metabolized differently in microalgae, bacteria, and diatoms where
it was accumulated and reduced into various inorganic forms (selenite,
selenide, or elemental Se) or partially incorporated into organic
Se mainly as selenomethionine. Brine shrimp and brine fly larva then
bioaccumulated Se from ingesting aquatic microorganisms and further
metabolized Se predominately into organic Se forms. Importantly, adult
brine flies, which hatched from aquatic larva, bioaccumulated the
highest Se concentrations of all organisms tested
Selenium Biotransformations in an Engineered Aquatic Ecosystem for Bioremediation of Agricultural Wastewater via Brine Shrimp Production
An
engineered aquatic ecosystem was specifically designed to bioremediate
selenium (Se), occurring as oxidized inorganic selenate from hypersalinized
agricultural drainage water while producing brine shrimp enriched
in organic Se and omega-3 and omega-6 fatty acids for use in value
added nutraceutical food supplements. Selenate was successfully bioremediated
by microalgal metabolism into organic Se (seleno-amino acids) and
partially removed via gaseous volatile Se formation. Furthermore,
filter-feeding brine shrimp that accumulated this organic Se were
removed by net harvest. Thriving in this engineered pond system, brine
shrimp (Artemia franciscana Kellogg)
and brine fly (Ephydridae sp.) have
major ecological relevance as important food sources for large populations
of waterfowl, breeding, and migratory shore birds. This aquatic ecosystem
was an ideal model for study because it mimics trophic interactions
in a Se polluted wetland. Inorganic selenate in drainage water was
metabolized differently in microalgae, bacteria, and diatoms where
it was accumulated and reduced into various inorganic forms (selenite,
selenide, or elemental Se) or partially incorporated into organic
Se mainly as selenomethionine. Brine shrimp and brine fly larva then
bioaccumulated Se from ingesting aquatic microorganisms and further
metabolized Se predominately into organic Se forms. Importantly, adult
brine flies, which hatched from aquatic larva, bioaccumulated the
highest Se concentrations of all organisms tested
Selenium Biotransformations in an Engineered Aquatic Ecosystem for Bioremediation of Agricultural Wastewater via Brine Shrimp Production
An
engineered aquatic ecosystem was specifically designed to bioremediate
selenium (Se), occurring as oxidized inorganic selenate from hypersalinized
agricultural drainage water while producing brine shrimp enriched
in organic Se and omega-3 and omega-6 fatty acids for use in value
added nutraceutical food supplements. Selenate was successfully bioremediated
by microalgal metabolism into organic Se (seleno-amino acids) and
partially removed via gaseous volatile Se formation. Furthermore,
filter-feeding brine shrimp that accumulated this organic Se were
removed by net harvest. Thriving in this engineered pond system, brine
shrimp (Artemia franciscana Kellogg)
and brine fly (Ephydridae sp.) have
major ecological relevance as important food sources for large populations
of waterfowl, breeding, and migratory shore birds. This aquatic ecosystem
was an ideal model for study because it mimics trophic interactions
in a Se polluted wetland. Inorganic selenate in drainage water was
metabolized differently in microalgae, bacteria, and diatoms where
it was accumulated and reduced into various inorganic forms (selenite,
selenide, or elemental Se) or partially incorporated into organic
Se mainly as selenomethionine. Brine shrimp and brine fly larva then
bioaccumulated Se from ingesting aquatic microorganisms and further
metabolized Se predominately into organic Se forms. Importantly, adult
brine flies, which hatched from aquatic larva, bioaccumulated the
highest Se concentrations of all organisms tested