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Jean-michel Mérillon - One of the best experts on this subject based on the ideXlab platform.

  • Constraint-based modeling highlights cell energy, redox status and α-ketoglutarate availability as metabolic drivers for anthocyanin accumulation in grape cells under nitrogen limitation
    Frontiers in Plant Science, 2018
    Co-Authors: Eric Soubeyrand, Sophie Colombié, Bertrand Beauvoit, Zhanwu Dai, Stéphanie Cluzet, Ghislaine Hilbert, Christel Renaud, Lilly Maneta-peyret, Martine Dieuaide-noubhani, Jean-michel Mérillon
    Abstract:

    Anthocyanin biosynthesis is regulated by environmental factors (such as light, temperature, and water availability) and nutrient status (such as carbon, nitrogen, and phosphate nutrition). Previous reports show that low nitrogen availability strongly enhances anthocyanin accumulation in non carbon-limited plant organs or cell suspensions. It has been hypothesized that high Carbon-to-Nitrogen Ratio would lead to an energy excess in plant cells, and that an increase in flavonoid pathway metabolic fluxes would act as an "energy escape valve," helping plant cells to cope with energy and carbon excess. However, this hypothesis has never been tested directly. To this end, we used the grapevine Vitis vinifera L. cultivar Gamay Teinturier (syn. Gamay Freaux or Freaux Tintorier, VIVC #4382) cell suspension line as a model system to study the regulation of anthocyanin accumulation in response to nitrogen supply. The cells were sub-cultured in the presence of either control (25 mM) or low (5 mM) nitrate concentRation. Targeted metabolomics and enzyme activity determinations were used to parametrize a constraint-based model describing both the central carbon and nitrogen metabolisms and the flavonoid (phenylpropanoid) pathway connected by the energy (ATP) and reducing power equivalents (NADPH and NADH) cofactors. The flux analysis (2 flux maps generated, for control and low nitrogen in culture medium) clearly showed that in low nitrogen-fed cells all the metabolic fluxes of central metabolism were decreased, whereas fluxes that consume energy and reducing power, were either increased (upper part of glycolysis, shikimate, and flavonoid pathway) or maintained (pentose phosphate pathway). Also, fluxes of flavanone 3 beta-hydroxylase, flavonol synthase, and anthocyanidin synthase were strongly increased, advocating for a regulation of the flavonoid pathway by alpha-ketoglutarate levels. These results strongly support the hypothesis of anthocyanin biosynthesis acting as an energy escape valve in plant cells, and they open new possibilities to manipulate flavonoid production in plant cells. They do not, however, support a role of anthocyanins as an effective mechanism for coping with carbon excess in high carbon to nitrogen Ratio situations in grape cells. Instead, constraint-based modeling output and biomass analysis indicate that carbon excess is dealt with by vacuolar storage of soluble sugars.

  • Presentation_2_Constraint-Based Modeling Highlights Cell Energy, Redox Status and α-Ketoglutarate Availability as Metabolic Drivers for Anthocyanin Accumulation in Grape Cells Under Nitrogen Limitation.pdf
    2018
    Co-Authors: Eric Soubeyrand, Sophie Colombié, Bertrand Beauvoit, Zhanwu Dai, Stéphanie Cluzet, Ghislaine Hilbert, Christel Renaud, Lilly Maneta-peyret, Martine Dieuaide-noubhani, Jean-michel Mérillon
    Abstract:

    Anthocyanin biosynthesis is regulated by environmental factors (such as light, temperature, and water availability) and nutrient status (such as carbon, nitrogen, and phosphate nutrition). Previous reports show that low nitrogen availability strongly enhances anthocyanin accumulation in non carbon-limited plant organs or cell suspensions. It has been hypothesized that high Carbon-to-Nitrogen Ratio would lead to an energy excess in plant cells, and that an increase in flavonoid pathway metabolic fluxes would act as an “energy escape valve,” helping plant cells to cope with energy and carbon excess. However, this hypothesis has never been tested directly. To this end, we used the grapevine Vitis vinifera L. cultivar Gamay Teinturier (syn. Gamay Freaux or Freaux Tintorier, VIVC #4382) cell suspension line as a model system to study the regulation of anthocyanin accumulation in response to nitrogen supply. The cells were sub-cultured in the presence of either control (25 mM) or low (5 mM) nitrate concentRation. Targeted metabolomics and enzyme activity determinations were used to parametrize a constraint-based model describing both the central carbon and nitrogen metabolisms and the flavonoid (phenylpropanoid) pathway connected by the energy (ATP) and reducing power equivalents (NADPH and NADH) cofactors. The flux analysis (2 flux maps generated, for control and low nitrogen in culture medium) clearly showed that in low nitrogen-fed cells all the metabolic fluxes of central metabolism were decreased, whereas fluxes that consume energy and reducing power, were either increased (upper part of glycolysis, shikimate, and flavonoid pathway) or maintained (pentose phosphate pathway). Also, fluxes of flavanone 3β-hydroxylase, flavonol synthase, and anthocyanidin synthase were strongly increased, advocating for a regulation of the flavonoid pathway by alpha-ketoglutarate levels. These results strongly support the hypothesis of anthocyanin biosynthesis acting as an energy escape valve in plant cells, and they open new possibilities to manipulate flavonoid production in plant cells. They do not, however, support a role of anthocyanins as an effective mechanism for coping with carbon excess in high carbon to nitrogen Ratio situations in grape cells. Instead, constraint-based modeling output and biomass analysis indicate that carbon excess is dealt with by vacuolar storage of soluble sugars.

  • Table_1_Constraint-Based Modeling Highlights Cell Energy, Redox Status and α-Ketoglutarate Availability as Metabolic Drivers for Anthocyanin Accumulation in Grape Cells Under Nitrogen Limitation.xlsx
    2018
    Co-Authors: Eric Soubeyrand, Sophie Colombié, Bertrand Beauvoit, Zhanwu Dai, Stéphanie Cluzet, Ghislaine Hilbert, Christel Renaud, Lilly Maneta-peyret, Martine Dieuaide-noubhani, Jean-michel Mérillon
    Abstract:

    Anthocyanin biosynthesis is regulated by environmental factors (such as light, temperature, and water availability) and nutrient status (such as carbon, nitrogen, and phosphate nutrition). Previous reports show that low nitrogen availability strongly enhances anthocyanin accumulation in non carbon-limited plant organs or cell suspensions. It has been hypothesized that high Carbon-to-Nitrogen Ratio would lead to an energy excess in plant cells, and that an increase in flavonoid pathway metabolic fluxes would act as an “energy escape valve,” helping plant cells to cope with energy and carbon excess. However, this hypothesis has never been tested directly. To this end, we used the grapevine Vitis vinifera L. cultivar Gamay Teinturier (syn. Gamay Freaux or Freaux Tintorier, VIVC #4382) cell suspension line as a model system to study the regulation of anthocyanin accumulation in response to nitrogen supply. The cells were sub-cultured in the presence of either control (25 mM) or low (5 mM) nitrate concentRation. Targeted metabolomics and enzyme activity determinations were used to parametrize a constraint-based model describing both the central carbon and nitrogen metabolisms and the flavonoid (phenylpropanoid) pathway connected by the energy (ATP) and reducing power equivalents (NADPH and NADH) cofactors. The flux analysis (2 flux maps generated, for control and low nitrogen in culture medium) clearly showed that in low nitrogen-fed cells all the metabolic fluxes of central metabolism were decreased, whereas fluxes that consume energy and reducing power, were either increased (upper part of glycolysis, shikimate, and flavonoid pathway) or maintained (pentose phosphate pathway). Also, fluxes of flavanone 3β-hydroxylase, flavonol synthase, and anthocyanidin synthase were strongly increased, advocating for a regulation of the flavonoid pathway by alpha-ketoglutarate levels. These results strongly support the hypothesis of anthocyanin biosynthesis acting as an energy escape valve in plant cells, and they open new possibilities to manipulate flavonoid production in plant cells. They do not, however, support a role of anthocyanins as an effective mechanism for coping with carbon excess in high carbon to nitrogen Ratio situations in grape cells. Instead, constraint-based modeling output and biomass analysis indicate that carbon excess is dealt with by vacuolar storage of soluble sugars.

  • Constraint-Based Modeling Highlights Cell Energy, Redox Status and α-Ketoglutarate Availability as Metabolic Drivers for Anthocyanin Accumulation in Grape Cells Under Nitrogen Limitation
    Frontiers Media S.A., 2018
    Co-Authors: Eric Soubeyrand, Sophie Colombié, Bertrand Beauvoit, Zhanwu Dai, Stéphanie Cluzet, Ghislaine Hilbert, Christel Renaud, Lilly Maneta-peyret, Martine Dieuaide-noubhani, Jean-michel Mérillon
    Abstract:

    Anthocyanin biosynthesis is regulated by environmental factors (such as light, temperature, and water availability) and nutrient status (such as carbon, nitrogen, and phosphate nutrition). Previous reports show that low nitrogen availability strongly enhances anthocyanin accumulation in non carbon-limited plant organs or cell suspensions. It has been hypothesized that high Carbon-to-Nitrogen Ratio would lead to an energy excess in plant cells, and that an increase in flavonoid pathway metabolic fluxes would act as an “energy escape valve,” helping plant cells to cope with energy and carbon excess. However, this hypothesis has never been tested directly. To this end, we used the grapevine Vitis vinifera L. cultivar Gamay Teinturier (syn. Gamay Freaux or Freaux Tintorier, VIVC #4382) cell suspension line as a model system to study the regulation of anthocyanin accumulation in response to nitrogen supply. The cells were sub-cultured in the presence of either control (25 mM) or low (5 mM) nitrate concentRation. Targeted metabolomics and enzyme activity determinations were used to parametrize a constraint-based model describing both the central carbon and nitrogen metabolisms and the flavonoid (phenylpropanoid) pathway connected by the energy (ATP) and reducing power equivalents (NADPH and NADH) cofactors. The flux analysis (2 flux maps generated, for control and low nitrogen in culture medium) clearly showed that in low nitrogen-fed cells all the metabolic fluxes of central metabolism were decreased, whereas fluxes that consume energy and reducing power, were either increased (upper part of glycolysis, shikimate, and flavonoid pathway) or maintained (pentose phosphate pathway). Also, fluxes of flavanone 3β-hydroxylase, flavonol synthase, and anthocyanidin synthase were strongly increased, advocating for a regulation of the flavonoid pathway by alpha-ketoglutarate levels. These results strongly support the hypothesis of anthocyanin biosynthesis acting as an energy escape valve in plant cells, and they open new possibilities to manipulate flavonoid production in plant cells. They do not, however, support a role of anthocyanins as an effective mechanism for coping with carbon excess in high carbon to nitrogen Ratio situations in grape cells. Instead, constraint-based modeling output and biomass analysis indicate that carbon excess is dealt with by vacuolar storage of soluble sugars

Xiangfeng Huang - One of the best experts on this subject based on the ideXlab platform.

  • bioconversion of volatile fatty acids derived from waste activated sludge into lipids by cryptococcus curvatus
    Bioresource Technology, 2016
    Co-Authors: Ming Yuan, Kaiming Peng, Ziheng Shen, Lijun Lu, Xiangfeng Huang
    Abstract:

    Abstract Pure volatile fatty acid (VFA) solution derived from waste activated sludge (WAS) was used to produce microbial lipids as culture medium in this study, which aimed to realize the resource recovery of WAS and provide low-cost feedstock for biodiesel production simultaneously. Cryptococcus curvatus was selected among three oleaginous yeast to produce lipids with VFAs derived from WAS. In batch cultivation, lipid contents increased from 10.2% to 16.8% when carbon to nitrogen Ratio increased from about 3.5 to 165 after removal of ammonia nitrogen by struvite precipitation. The lipid content further increased to 39.6% and the biomass increased from 1.56 g/L to 4.53 g/L after cultivation for five cycles using sequencing batch culture (SBC) strategy. The lipids produced from WAS-derived VFA solution contained nearly 50% of monounsaturated fatty acids, including palmitic acid, heptadecanoic acid, ginkgolic acid, stearic acid, oleic acid, and linoleic acid, which showed the adequacy of biodiesel production.

  • culture strategies for lipid production using acetic acid as sole carbon source by rhodosporidium toruloides
    Bioresource Technology, 2016
    Co-Authors: Xiangfeng Huang, Kaiming Peng, Jianan Liu, Gaoxiang Yang, Jia Liu
    Abstract:

    Rhodosporidium toruloides AS 2.1389 was tested using different concentRations of acetic acid as a low-cost carbon source for the production of microbial lipids, which are good raw materials for biodiesel production. It grew and had higher lipid contents in media containing 4-20 g/L acetic acid as the sole carbon source, compared with that in glucose-containing media under the same culture conditions. At acetic acid concentRations as high as 20 g/L and the optimal Carbon-to-Nitrogen Ratio (C/N) of 200 in a batch culture, the highest biomass production was 4.35 g/L, with a lipid content of 48.2%. At acetic acid concentRations as low as 4 g/L, a sequencing batch culture (SBC) with a C/N of 100 increased biomass production to 4.21 g/L, with a lipid content of 38.6%. These results provide usable culture strategies for lipid production by R. toruloides AS 2.1389 when using diverse waste-derived volatile fatty acids.

Eric Soubeyrand - One of the best experts on this subject based on the ideXlab platform.

  • Constraint-based modeling highlights cell energy, redox status and α-ketoglutarate availability as metabolic drivers for anthocyanin accumulation in grape cells under nitrogen limitation
    Frontiers in Plant Science, 2018
    Co-Authors: Eric Soubeyrand, Sophie Colombié, Bertrand Beauvoit, Zhanwu Dai, Stéphanie Cluzet, Ghislaine Hilbert, Christel Renaud, Lilly Maneta-peyret, Martine Dieuaide-noubhani, Jean-michel Mérillon
    Abstract:

    Anthocyanin biosynthesis is regulated by environmental factors (such as light, temperature, and water availability) and nutrient status (such as carbon, nitrogen, and phosphate nutrition). Previous reports show that low nitrogen availability strongly enhances anthocyanin accumulation in non carbon-limited plant organs or cell suspensions. It has been hypothesized that high Carbon-to-Nitrogen Ratio would lead to an energy excess in plant cells, and that an increase in flavonoid pathway metabolic fluxes would act as an "energy escape valve," helping plant cells to cope with energy and carbon excess. However, this hypothesis has never been tested directly. To this end, we used the grapevine Vitis vinifera L. cultivar Gamay Teinturier (syn. Gamay Freaux or Freaux Tintorier, VIVC #4382) cell suspension line as a model system to study the regulation of anthocyanin accumulation in response to nitrogen supply. The cells were sub-cultured in the presence of either control (25 mM) or low (5 mM) nitrate concentRation. Targeted metabolomics and enzyme activity determinations were used to parametrize a constraint-based model describing both the central carbon and nitrogen metabolisms and the flavonoid (phenylpropanoid) pathway connected by the energy (ATP) and reducing power equivalents (NADPH and NADH) cofactors. The flux analysis (2 flux maps generated, for control and low nitrogen in culture medium) clearly showed that in low nitrogen-fed cells all the metabolic fluxes of central metabolism were decreased, whereas fluxes that consume energy and reducing power, were either increased (upper part of glycolysis, shikimate, and flavonoid pathway) or maintained (pentose phosphate pathway). Also, fluxes of flavanone 3 beta-hydroxylase, flavonol synthase, and anthocyanidin synthase were strongly increased, advocating for a regulation of the flavonoid pathway by alpha-ketoglutarate levels. These results strongly support the hypothesis of anthocyanin biosynthesis acting as an energy escape valve in plant cells, and they open new possibilities to manipulate flavonoid production in plant cells. They do not, however, support a role of anthocyanins as an effective mechanism for coping with carbon excess in high carbon to nitrogen Ratio situations in grape cells. Instead, constraint-based modeling output and biomass analysis indicate that carbon excess is dealt with by vacuolar storage of soluble sugars.

  • Presentation_2_Constraint-Based Modeling Highlights Cell Energy, Redox Status and α-Ketoglutarate Availability as Metabolic Drivers for Anthocyanin Accumulation in Grape Cells Under Nitrogen Limitation.pdf
    2018
    Co-Authors: Eric Soubeyrand, Sophie Colombié, Bertrand Beauvoit, Zhanwu Dai, Stéphanie Cluzet, Ghislaine Hilbert, Christel Renaud, Lilly Maneta-peyret, Martine Dieuaide-noubhani, Jean-michel Mérillon
    Abstract:

    Anthocyanin biosynthesis is regulated by environmental factors (such as light, temperature, and water availability) and nutrient status (such as carbon, nitrogen, and phosphate nutrition). Previous reports show that low nitrogen availability strongly enhances anthocyanin accumulation in non carbon-limited plant organs or cell suspensions. It has been hypothesized that high Carbon-to-Nitrogen Ratio would lead to an energy excess in plant cells, and that an increase in flavonoid pathway metabolic fluxes would act as an “energy escape valve,” helping plant cells to cope with energy and carbon excess. However, this hypothesis has never been tested directly. To this end, we used the grapevine Vitis vinifera L. cultivar Gamay Teinturier (syn. Gamay Freaux or Freaux Tintorier, VIVC #4382) cell suspension line as a model system to study the regulation of anthocyanin accumulation in response to nitrogen supply. The cells were sub-cultured in the presence of either control (25 mM) or low (5 mM) nitrate concentRation. Targeted metabolomics and enzyme activity determinations were used to parametrize a constraint-based model describing both the central carbon and nitrogen metabolisms and the flavonoid (phenylpropanoid) pathway connected by the energy (ATP) and reducing power equivalents (NADPH and NADH) cofactors. The flux analysis (2 flux maps generated, for control and low nitrogen in culture medium) clearly showed that in low nitrogen-fed cells all the metabolic fluxes of central metabolism were decreased, whereas fluxes that consume energy and reducing power, were either increased (upper part of glycolysis, shikimate, and flavonoid pathway) or maintained (pentose phosphate pathway). Also, fluxes of flavanone 3β-hydroxylase, flavonol synthase, and anthocyanidin synthase were strongly increased, advocating for a regulation of the flavonoid pathway by alpha-ketoglutarate levels. These results strongly support the hypothesis of anthocyanin biosynthesis acting as an energy escape valve in plant cells, and they open new possibilities to manipulate flavonoid production in plant cells. They do not, however, support a role of anthocyanins as an effective mechanism for coping with carbon excess in high carbon to nitrogen Ratio situations in grape cells. Instead, constraint-based modeling output and biomass analysis indicate that carbon excess is dealt with by vacuolar storage of soluble sugars.

  • Table_1_Constraint-Based Modeling Highlights Cell Energy, Redox Status and α-Ketoglutarate Availability as Metabolic Drivers for Anthocyanin Accumulation in Grape Cells Under Nitrogen Limitation.xlsx
    2018
    Co-Authors: Eric Soubeyrand, Sophie Colombié, Bertrand Beauvoit, Zhanwu Dai, Stéphanie Cluzet, Ghislaine Hilbert, Christel Renaud, Lilly Maneta-peyret, Martine Dieuaide-noubhani, Jean-michel Mérillon
    Abstract:

    Anthocyanin biosynthesis is regulated by environmental factors (such as light, temperature, and water availability) and nutrient status (such as carbon, nitrogen, and phosphate nutrition). Previous reports show that low nitrogen availability strongly enhances anthocyanin accumulation in non carbon-limited plant organs or cell suspensions. It has been hypothesized that high Carbon-to-Nitrogen Ratio would lead to an energy excess in plant cells, and that an increase in flavonoid pathway metabolic fluxes would act as an “energy escape valve,” helping plant cells to cope with energy and carbon excess. However, this hypothesis has never been tested directly. To this end, we used the grapevine Vitis vinifera L. cultivar Gamay Teinturier (syn. Gamay Freaux or Freaux Tintorier, VIVC #4382) cell suspension line as a model system to study the regulation of anthocyanin accumulation in response to nitrogen supply. The cells were sub-cultured in the presence of either control (25 mM) or low (5 mM) nitrate concentRation. Targeted metabolomics and enzyme activity determinations were used to parametrize a constraint-based model describing both the central carbon and nitrogen metabolisms and the flavonoid (phenylpropanoid) pathway connected by the energy (ATP) and reducing power equivalents (NADPH and NADH) cofactors. The flux analysis (2 flux maps generated, for control and low nitrogen in culture medium) clearly showed that in low nitrogen-fed cells all the metabolic fluxes of central metabolism were decreased, whereas fluxes that consume energy and reducing power, were either increased (upper part of glycolysis, shikimate, and flavonoid pathway) or maintained (pentose phosphate pathway). Also, fluxes of flavanone 3β-hydroxylase, flavonol synthase, and anthocyanidin synthase were strongly increased, advocating for a regulation of the flavonoid pathway by alpha-ketoglutarate levels. These results strongly support the hypothesis of anthocyanin biosynthesis acting as an energy escape valve in plant cells, and they open new possibilities to manipulate flavonoid production in plant cells. They do not, however, support a role of anthocyanins as an effective mechanism for coping with carbon excess in high carbon to nitrogen Ratio situations in grape cells. Instead, constraint-based modeling output and biomass analysis indicate that carbon excess is dealt with by vacuolar storage of soluble sugars.

  • Constraint-Based Modeling Highlights Cell Energy, Redox Status and α-Ketoglutarate Availability as Metabolic Drivers for Anthocyanin Accumulation in Grape Cells Under Nitrogen Limitation
    Frontiers Media S.A., 2018
    Co-Authors: Eric Soubeyrand, Sophie Colombié, Bertrand Beauvoit, Zhanwu Dai, Stéphanie Cluzet, Ghislaine Hilbert, Christel Renaud, Lilly Maneta-peyret, Martine Dieuaide-noubhani, Jean-michel Mérillon
    Abstract:

    Anthocyanin biosynthesis is regulated by environmental factors (such as light, temperature, and water availability) and nutrient status (such as carbon, nitrogen, and phosphate nutrition). Previous reports show that low nitrogen availability strongly enhances anthocyanin accumulation in non carbon-limited plant organs or cell suspensions. It has been hypothesized that high Carbon-to-Nitrogen Ratio would lead to an energy excess in plant cells, and that an increase in flavonoid pathway metabolic fluxes would act as an “energy escape valve,” helping plant cells to cope with energy and carbon excess. However, this hypothesis has never been tested directly. To this end, we used the grapevine Vitis vinifera L. cultivar Gamay Teinturier (syn. Gamay Freaux or Freaux Tintorier, VIVC #4382) cell suspension line as a model system to study the regulation of anthocyanin accumulation in response to nitrogen supply. The cells were sub-cultured in the presence of either control (25 mM) or low (5 mM) nitrate concentRation. Targeted metabolomics and enzyme activity determinations were used to parametrize a constraint-based model describing both the central carbon and nitrogen metabolisms and the flavonoid (phenylpropanoid) pathway connected by the energy (ATP) and reducing power equivalents (NADPH and NADH) cofactors. The flux analysis (2 flux maps generated, for control and low nitrogen in culture medium) clearly showed that in low nitrogen-fed cells all the metabolic fluxes of central metabolism were decreased, whereas fluxes that consume energy and reducing power, were either increased (upper part of glycolysis, shikimate, and flavonoid pathway) or maintained (pentose phosphate pathway). Also, fluxes of flavanone 3β-hydroxylase, flavonol synthase, and anthocyanidin synthase were strongly increased, advocating for a regulation of the flavonoid pathway by alpha-ketoglutarate levels. These results strongly support the hypothesis of anthocyanin biosynthesis acting as an energy escape valve in plant cells, and they open new possibilities to manipulate flavonoid production in plant cells. They do not, however, support a role of anthocyanins as an effective mechanism for coping with carbon excess in high carbon to nitrogen Ratio situations in grape cells. Instead, constraint-based modeling output and biomass analysis indicate that carbon excess is dealt with by vacuolar storage of soluble sugars

Sangill Lee - One of the best experts on this subject based on the ideXlab platform.

  • evaluation of a three stage biological aerated filter system combined recirculation dynamic flow in treating low carbon to nitrogen Ratio wastewater
    Environmental Engineering Science, 2009
    Co-Authors: Hongduck Ryu, Joohyoung Kang, Sangill Lee
    Abstract:

    Abstract In this study, a three-stage biological aerated filter (BAF) system was proposed to enhance nitrogen removal in the treatment of low Carbon-to-Nitrogen Ratio (C/N Ratio) municipal wastewater. Laboratory experiments were conducted at three different recirculation Ratios of 1, 2, and 3. Effects of dynamic flow were also evaluated in this study. Results of the long-term opeRation of the three-stage BAF system in dynamic flow showed nitrogen removal was affected by the both recirculation Ratio and C/N Ratio in dynamic flow. Dynamic flow enabled the nitrogen removal efficiency of the system to be higher than that of nondynamic flow system in treating low C/N Ratio wastewater due to the more efficient use of organic substrates. Overall NH4-N removal performance was stable with a removal efficiency of 99% on average during the opeRational period due to the unique system configuRation where independent nitrification occurred. It was concluded that the three-stage BAF system proposed in this study provide...

  • nitrogen removal from low carbon to nitrogen wastewater in four stage biological aerated filter system
    Process Biochemistry, 2008
    Co-Authors: Hongduck Ryu, Daekeun Kim, Heuneun Lim, Sangill Lee
    Abstract:

    Abstract In this study, a four-stage biological aerated filter (BAF) system was proposed for the enhancement of nitrogen removal in the treatment of low Carbon-to-Nitrogen Ratio (C/N Ratio) municipal wastewater. Laboratory experiments were conducted at two different hydraulic retention times (HRTs), i.e., 3 h and 6 h. Results of the long-term opeRation of the BAF system showed that its overall NH 4 -N removal performance was stable with the removal efficiency of 95–96% on average, regardless of HRT applied. The effectiveness of the proposed BAF was observed in denitrification performance. At the total chemical oxygen demand (TCOD) to total kjeldahl nitrogen (TKN) Ratio of 3:6, the effluent NO 3 -N concentRation of denitrification column was 2.7 mg/L. It was concluded that the four-stage BAF system proposed in this study was excellent in nitrogen removal performance by employing four-column functioning as sorption, nitrification, denitrification and purification, respectively.

Giorgio Mannina - One of the best experts on this subject based on the ideXlab platform.

  • influence of carbon to nitrogen Ratio on nitrous oxide emission in an integrated fixed film activated sludge membrane bioreactor plant
    Journal of Cleaner Production, 2018
    Co-Authors: Giorgio Mannina, Marco Capodici, Alida Cosenza, Daniele Di Trapani, George A Ekama, Hallvard Odegaard, Mark M C Van Loosdrecht
    Abstract:

    Abstract In this study a University of Cape Town (UCT) Integrated Fixed Film Activated Sludge (IFAS) Membrane BioReactor (MBR) wastewater treatment plant was monitored in terms of nitrous oxide (N2O) emissions. The short term effect on the N2O emission due to the influent Carbon-to-Nitrogen (C/N) Ratio variation (C/N Ratios of 2, 5 and 10 gCOD/gN) was evaluated. Since in a previous study, the effect of the C/N Ratio was studied in the same system without biofilm (UCT-MBR configuRation) the main aim here was to investigate the role of biofilms on N2O emissions. Under all the investigated C/N Ratios, the N2O fluxes and the average emission factors were lower than that of previous studies with no biofilm presence. The total average N2O emission was 0.5% of the influent nitrogen with biofilm (IFAS system) and 3.5% without biofilm. This result emphasizes the potential role of the biofilms in attenuating the N2O emissions especially in the case of stress conditions (i.e., low C/N influent Ratios). An increase of N2O flux from the anoxic reactor (till 28 mgN2O m−2h−1) occurred at the lowest influent C/N tested (2 gCOD/gN - phase III). At C/N equal to 2 gCOD/gN the anoxic reactor was the main source of N2O, contributing 45% of all produced N2O. This result was attributed to an incomplete denitrification caused by a lack of organic carbon and a slight increase of dissolved oxygen concentRation.

  • nitrous oxide emission in a university of cape town membrane bioreactor the effect of carbon to nitrogen Ratio
    Journal of Cleaner Production, 2017
    Co-Authors: Giorgio Mannina, Marco Capodici, Alida Cosenza, Daniele Di Trapani, Mark C M Van Loosdrecht
    Abstract:

    Abstract The effect of the Carbon-to-Nitrogen (C/N) Ratio in the influent on the nitrous oxide (N 2 O) emission from a University of Cape Town Membrane BioReactor pilot plant was investigated. The membrane was located in a separate tank to single out the production of N 2 O due to the biological processes from N 2 O stripping as a result of the extra aeRation needed for the mitigation of membrane fouling. The experimental campaign was divided into two phases, each characterized by a different C/N Ratio (namely, 10 and 5 mgCOD/mgTN, Phase I and Phase II, respectively). The decrease of the C/N Ratio promoted the increase of N 2 O emissions in both gaseous and dissolved phases, mainly due to a decreased nitrification/denitrification capacity of the system. The highest N 2 O concentRation in the dissolved phase was found in the permeate. This result suggests that the dissolved N 2 O in the permeate stream discharged from a MBR cannot be neglected. The total N 2 O emission was approximately of 0.01% and 0.1% of the total influent nitrogen load for the Phase I and Phase II, respectively. The findings suggest that the C/N Ratio represents an indirect cause of N 2 O emission; the low C/N value (Phase II) led to the increase of pH and free ammonia causing a stress effect on the growth of nitrifying species increasing the N 2 O emission.