7 research outputs found
Efficiency of RAPD and ISSR markers system in accessing genetic variation of rice bean (Vigna umbellata) landraces
Effects of wastewater treatment plant effluent inputs on planktonic metabolic rates and microbial community composition in the Baltic Sea
The Baltic Sea is the world's largest area suffering from
eutrophication-driven hypoxia. Low oxygen levels are threatening its
biodiversity and ecosystem functioning. The main causes for
eutrophication-driven hypoxia are high nutrient loadings and global warming.
Wastewater treatment plants (WWTP) contribute to eutrophication as they are
important sources of nitrogen to coastal areas. Here, we evaluated the
effects of wastewater treatment plant effluent inputs on Baltic Sea
planktonic communities in four experiments. We tested for effects of effluent
inputs on chlorophyll <i>a</i> content, bacterial community composition, and
metabolic rates: gross primary production (GPP), net community production
(NCP), community respiration (CR) and bacterial production (BP).
Nitrogen-rich dissolved organic matter (DOM) inputs from effluents increased
bacterial production and decreased primary production and community
respiration. Nutrient amendments and seasonally variable environmental
conditions lead to lower alpha-diversity and shifts in bacterial community
composition (e.g. increased abundance of a few cyanobacterial populations in
the summer experiment), concomitant with changes in metabolic rates. An
increase in BP and decrease in CR could be caused by high lability of the
DOM that can support secondary bacterial production, without an increase in
respiration. Increases in bacterial production and simultaneous decreases of
primary production lead to more carbon being consumed in the microbial loop,
and may shift the ecosystem towards heterotrophy
Dissolved Organic Nitrogen Inputs from Wastewater Treatment Plant Effluents Increase Responses of Planktonic Metabolic Rates to Warming.
Increased anthropogenic pressures on coastal marine ecosystems in the last century are threatening their biodiversity and functioning. Global warming and increases in nutrient loadings are two major stressors affecting these systems. Global warming is expected to increase both atmospheric and water temperatures and increase precipitation and terrestrial runoff, further increasing organic matter and nutrient inputs to coastal areas. Dissolved organic nitrogen (DON) concentrations frequently exceed those of dissolved inorganic nitrogen in aquatic systems. Many components of the DON pool have been shown to supply nitrogen nutrition to phytoplankton and bacteria. Predictions of how global warming and eutrophication will affect metabolic rates and dissolved oxygen dynamics in the future are needed to elucidate their impacts on biodiversity and ecosystem functioning. Here, we experimentally determine the effects of simultaneous DON additions and warming on planktonic community metabolism in the Baltic Sea, the largest coastal area suffering from eutrophication-driven hypoxia. Both bacterioplankton community composition and metabolic rates changed in relation to temperature. DON additions from wastewater treatment plant effluents significantly increased the activation energies for community respiration and gross primary production. Activation energies for community respiration were higher than those for gross primary production. Results support the prediction that warming of the Baltic Sea will enhance planktonic respiration rates faster than it will for planktonic primary production. Higher increases in respiration rates than in production may lead to the depletion of the oxygen pool, further aggravating hypoxia in the Baltic Sea
A non-classical route of efficient plant uptake verified with fluorescent nanoparticles and root adhesion forces investigated using AFM
Classical plant uptake is limited to hydrophilic or water-dispersible material. Therefore, in order to test the uptake behaviour of hydrophobic particles, here, we tested the fate of hydrophobic particles (oleylamine coated Cu2-xSe NPs (CS@OA)) in comparison to hydrophilic particles (chitosan-coated Cu2-xSe NPs (CS@CH)) by treatment on the plant roots. Surprisingly, hydrophobic CS@OA NPs have been found to be ~ 1.3 times more efficient than hydrophilic CS@CH NPs in tomato plant root penetration. An atomic force microscopy (AFM) adhesion force experiment confirms that hydrophobic NPs experience non-spontaneous yet energetically favorable root trapping and penetration. Further, a relative difference in the hydrophobic vs. hydrophilic NPs movement from roots to shoots has been observed and found related to the change in protein corona as identified by two dimensional-polyacrylamide gel electrophoresis (2D-PAGE) analysis. Finally, the toxicity assays at the give concentration showed that Cu2-xSe NPs lead to non-significant toxicity as compared to control. This technology may find an advantage in fertilizer application
A non-classical route of efficient plant uptake verified with fluorescent nanoparticles and root adhesion forces investigated using AFM
Classical plant uptake is limited to hydrophilic or water-dispersible material. Therefore, in order to test the uptake behaviour of hydrophobic particles, here, we tested the fate of hydrophobic particles (oleylamine coated Cu2-xSe NPs (CS@OA)) in comparison to hydrophilic particles (chitosan-coated Cu2-xSe NPs (CS@CH)) by treatment on the plant roots. Surprisingly, hydrophobic CS@OA NPs have been found to be ~ 1.3 times more efficient than hydrophilic CS@CH NPs in tomato plant root penetration. An atomic force microscopy (AFM) adhesion force experiment confirms that hydrophobic NPs experience non-spontaneous yet energetically favorable root trapping and penetration. Further, a relative difference in the hydrophobic vs. hydrophilic NPs movement from roots to shoots has been observed and found related to the change in protein corona as identified by two dimensional-polyacrylamide gel electrophoresis (2D-PAGE) analysis. Finally, the toxicity assays at the give concentration showed that Cu2-xSe NPs lead to non-significant toxicity as compared to control. This technology may find an advantage in fertilizer application
Dissolved Organic Nitrogen Inputs from Wastewater Treatment Plant Effluents Increase Responses of Planktonic Metabolic Rates to Warming
Increased anthropogenic pressures
on coastal marine ecosystems
in the last century are threatening their biodiversity and functioning.
Global warming and increases in nutrient loadings are two major stressors
affecting these systems. Global warming is expected to increase both
atmospheric and water temperatures and increase precipitation and
terrestrial runoff, further increasing organic matter and nutrient
inputs to coastal areas. Dissolved organic nitrogen (DON) concentrations
frequently exceed those of dissolved inorganic nitrogen in aquatic
systems. Many components of the DON pool have been shown to supply
nitrogen nutrition to phytoplankton and bacteria. Predictions of how
global warming and eutrophication will affect metabolic rates and
dissolved oxygen dynamics in the future are needed to elucidate their
impacts on biodiversity and ecosystem functioning. Here, we experimentally
determine the effects of simultaneous DON additions and warming on
planktonic community metabolism in the Baltic Sea, the largest coastal
area suffering from eutrophication-driven hypoxia. Both bacterioplankton
community composition and metabolic rates changed in relation to temperature.
DON additions from wastewater treatment plant effluents significantly
increased the activation energies for community respiration and gross
primary production. Activation energies for community respiration
were higher than those for gross primary production. Results support
the prediction that warming of the Baltic Sea will enhance planktonic
respiration rates faster than it will for planktonic primary production.
Higher increases in respiration rates than in production may lead
to the depletion of the oxygen pool, further aggravating hypoxia in
the Baltic Sea