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1.
J Environ Manage ; 344: 118742, 2023 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-37573696

RESUMO

In Europe, rapeseed is a common oilseed crop, resulting in the production of 20 million tons of rapeseed press cake yearly. This press cake can be further upcycled and a protein fraction can be extracted for food purposes, leaving de-proteinized fiber-rich residues. This study examined the use of these residues in the production of oyster mushrooms (Pleurotus ostreatus) and of the spent substrate as feed, since mushroom cultivation may improve the feed properties of substrate. In terms of mushroom production, the addition of rapeseed press residues was beneficial, giving significantly higher biological efficiency (BE = 93.1 ± 11.0%) compared with the control, sugar beet pulp substrate (70.0 ± 6.6%). This increase in productivity can most likely be explained by higher energy content in the substrate supplemented with lipid-rich rapeseed residues. Despite differences in BE between the substrates, high similarity was observed in lipid composition of the fruiting bodies (lipid profile dominated by linoleic acid (18:2), palmitic acid (16:0), and oleic acid (18:1)), and in protein and moisture content. After mushroom harvest, approximately 70% of the initial dry weight of both substrates remained as a possible feed source. Both substrates had significantly lower levels of carbohydrates and unchanged neutral detergent fiber content after mushroom harvest, and both gave lower in vitro digestibility, total gas production, and methane production. However, protein concentration differed between the substrates, with the highest concentration (15.8% of dry weight) found in spent substrate containing rapeseed press residues. The result of the present study suggests that the de-proteinized rapeseed press residue is a resource well-suited for use in the production of mushrooms and feed.


Assuntos
Agaricales , Brassica napus , Brassica rapa , Pleurotus , Pleurotus/química , Pleurotus/metabolismo , Agaricales/química , Agaricales/metabolismo , Lipídeos
2.
J Environ Manage ; 313: 114997, 2022 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-35395528

RESUMO

Anaerobic digestate based on food waste is increasingly used as fertilizer in food production. This study examined the characteristics of anaerobic digestate based on food waste from three biogas plants in Sweden. The characterization included measurements of heavy metals (n = 7), chemicals of emerging concern (CECs), such as currently used drugs and pesticides (n = 133), and an extended range of food-borne pathogens, including two notable sporeformers and some widespread antibiotic-resistant bacteria. The amounts of Escherichia coli, enterococci, and Salmonella and the concentrations of the target heavy metals were all below the maximum accepted levels at all three locations studied. However, the spore-forming Bacillus cereus was found to be present at high levels in samples from all three biogas plants. Among the 133 CECs investigated, 48 were detected at least once, and the highest concentrations were found for pyroxidine, nicotine, caffeine, theobromine, and nicotine. The biofertilizers from the different biogas plants had similar CEC profiles, which indicate similarities in household waste composition and thorough mixing in the biogas plants. If this profile is found to be spatially and temporally consistent, it can help regulators to establish priority lists of CECs of top concern. Assuming increasing use of biofertilizers for food production in the future, it would be beneficial to have concentration limits for CECs Risk estimation based on risk quotients (RQs) indicated generally low environmental risks associated with application of biofertilizer to soils for food crop production. However, the toxicity of CEC mixtures needs to be considered when estimating the risks from application of biofertilizers on agricultural land or in other production systems.


Assuntos
Metais Pesados , Eliminação de Resíduos , Anaerobiose , Biocombustíveis , Alimentos , Nicotina , Esgotos/química
3.
Biodegradation ; 29(6): 557-565, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30171388

RESUMO

Recent research has demonstrated the potential of using filamentous fungi to form pellets with microalgae (biopellets), in order to facilitate harvesting of microalgae from water following algae-based treatment of wastewater. In parallel, there is a need to develop techniques for removing organic pollutants such as pesticides and pharmaceuticals from wastewater. In experiments using the microalga Chlorella vulgaris, the filamentous fungus Aspergillus niger and biopellets composed of these microorganisms, this study investigated whether fungal-assisted algal harvesting can also remove pesticides from contaminated water. A mixture of 38 pesticides was tested and the concentrations of 17 of these were found to be reduced significantly in the biopellet treatment, compared with the control. After harvesting, the concentration of total pesticides in the algal treatment did not differ significantly from that in the control. However, in the fungal treatment and biopellet treatment, the concentration was significantly lower (59.6 ± 2.0 µg/L and 56.1 ± 2.8 µg/L, respectively) than in the control (66.6 ± 1.0 µg/L). Thus fungal-assisted algal harvesting through biopellet formation can also provide scope for removing organic pollutants from wastewater, with removal mainly being performed by the fungus.


Assuntos
Chlorella vulgaris/crescimento & desenvolvimento , Recuperação e Remediação Ambiental/métodos , Fungos/metabolismo , Microalgas/crescimento & desenvolvimento , Praguicidas/isolamento & purificação , Poluentes Químicos da Água/isolamento & purificação , Água/química , Biodegradação Ambiental , Análise da Demanda Biológica de Oxigênio , Biomassa , Carbofurano/análise , Triazinas/análise , Águas Residuárias/microbiologia
4.
Bioprocess Biosyst Eng ; 40(4): 625-631, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28025700

RESUMO

The effluent from the biogas process was tested as a nutrient source during cultivation of the protein-rich and edible microalgae Spirulina (Arthrospira platensis) and compared with conventional Spirulina medium. Equal biomass production was observed until late exponential phase and no significant differences could be observed between the treatments in protein amount, amino acid composition, and total lipid concentration. The concentration of the pigment phycocyanin differed significantly between Spirulina medium and the effluent-based medium (63.3 ± 11.7 and 86.2 ± 1.9 mg g-1, respectively). Slightly higher concentrations of saturated fatty acids, mainly palmitic acid, were observed in the biomass produced in Spirulina medium than in that produced in the effluent-based medium. In the biomass produced in the effluent-based medium, the cadmium concentration was 0.07 ± 0.05 mg kg-1 of dry weight, whereas it was below the detection limit in the biomass produced in Spirulina medium. There is a need to identify new food and feed resources and a possible future scenario is to integrate Spirulina production into the biogas plant for protein production as it contains more than 60% of protein on dry weight basis. In that scenario, it is important to control heavy metal concentrations in the biogas slurry fed to Spirulina.


Assuntos
Biocombustíveis , Meios de Cultura/química , Microalgas/crescimento & desenvolvimento , Spirulina/crescimento & desenvolvimento
5.
Int J Phytoremediation ; 19(5): 500-504, 2017 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-27739868

RESUMO

Removal of cadmium (Cd) present at low levels (1 µg L-1) in water was investigated using three different microorganism treatments: the microalga Chlorella vulgaris, the fungus Aspergillus niger, and for the first time biopellets composed of C. vulgaris and A. niger. After 5 days, all microorganism treatments resulted in significantly lower Cd concentrations compared with the control. Biopellets treatment resulted in significantly lower pH values than other microorganism treatments, indicating that the biopellets should be investigated further for their water treatment capacity, since pH is a factor affecting the fate of numerous pollutants in water. Use of biopellets as a method to simplify harvesting of microalgae from water is also suggested.


Assuntos
Aspergillus niger/metabolismo , Cloreto de Cádmio/metabolismo , Cádmio/metabolismo , Chlorella vulgaris/metabolismo , Poluentes Químicos da Água/metabolismo , Biodegradação Ambiental , Biomassa
6.
Curr Microbiol ; 69(5): 699-702, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24985199

RESUMO

Formation of biofilm on surfaces is a common feature in aquatic environments. Major groups of inhabitants in conditions where light is present are photoautotrophic microorganisms, such as cyanobacteria and microalgae. This study examined the effect of light quality on growth and biofilm formation of the microalgal species Chlorella vulgaris. Dense biofilm formation and aggregated growth of cells were observed in treatments exposed to blue, purple and white light. Less dense biofilm formation and solitary growth of cells were observed in treatments exposed to red, yellow or green light. Microalgal biofilms are of high importance in many respects, not least from an economic perspective. One example is the intense efforts undertaken to control biofilm formation on technical surfaces such as ship hulls. The present study suggests that light quality plays a role in biofilm formation and that blue-light receptors may be involved.


Assuntos
Biofilmes/crescimento & desenvolvimento , Chlorella vulgaris/fisiologia , Chlorella vulgaris/efeitos da radiação , Luz , Chlorella vulgaris/crescimento & desenvolvimento
7.
Environ Pollut ; 319: 120958, 2023 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-36603758

RESUMO

Recovery and reuse of nutrients is a major challenge in agriculture. A new process contributing to a circular economy is the anaerobic digestion of food waste, which is a sustainable way of recycling nutrients as the digestate can be used as fertiliser in agriculture and horticulture. However, the digestate may be polluted with contaminants of emerging concern (CECs) that can be circulated back into the food chain, posing a risk to the environment and human health. In this work, the nutrient solution was spiked with 18 selected CECs frequently detected in food waste biogas facilities, and subsequent uptake and fate of these CECs were evaluated in pak choi grown in two different nutrient solutions (mineral and organic). All spiked compounds except two (propylparaben, fenbendazole) were taken up by pak choi plants, with perfluorobutanoic acid (PFBA) and sertraline displaying the highest concentrations (270 and 190 µg/kg fresh weight, respectively). There were no statistically significant differences in uptake between mineral and organic nutrient solutions. Uptake of per- and polyfluoroalkyl substances (PFAS) was negatively correlated with perfluorocarbon chain length and dependent on the functional group (r = -0.73). Sixteen transformation products (TPs) were tentatively identified using suspect screening, most of which were Phase II or even Phase III metabolites. Six of these TPs were identified for the first time in plant metabolism and their metabolic pathways were considered.


Assuntos
Brassica rapa , Eliminação de Resíduos , Humanos , Brassica rapa/metabolismo , Alimentos , Transporte Biológico , Agricultura
8.
ACS Omega ; 8(6): 5361-5376, 2023 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-36816655

RESUMO

Cellulose fiber rejects from industrial-scale recycling of waste papers were dried and de-ashed using a combined cyclone-drying and sieving process. The upgraded fiber reject was used as a component of substrates for the cultivation of Pleurotus ostreatus and Pleurotus eryngii mushrooms. Acetic acid (AA) and acid whey (AW) were used to adjust the pH of fiber reject-based substrates. Spent substrate (SMS) was used for the production of activated biochar using H3PO4 and KOH as activating agents and pyrolysis temperatures of 500, 600, and 700 °C. The effectiveness of the biochars in removing pollutants from water was determined using acetaminophen and amoxicillin. By using a feeding rate of 250 kg/h and a drying air temperature of 70 °C, the moisture content of the raw fiber rejects (57.8 wt %) was reduced to 5.4 wt %, and the ash content (39.2 wt %) was reduced to 21.5 wt %. Substrates with 60 and 80 wt % de-ashed cellulose fiber were colonized faster than a birch wood-based control substrate. The adjustment of the pH of these two substrates to approximately 6.5 by using AA led to longer colonization times but biological efficiencies (BEs) that were higher or comparable to that of the control substrate. The contents of ash, crude fiber, crude fat, and crude protein of fruit bodies grown on fiber reject-based substrates were comparable to that of those grown on control substrates, and the contents of toxic heavy metals, that is, As, Pb, Cd, and Hg, were well below the up-limit values for food products set in EC regulations. Activated biochar produced from fiber reject-based SMS at a temperature of 700 °C resulted in a surface area (BET) of 396 m2/g (H3PO4-activated biochar) and 199 m2/g (KOH-activated biochar). For both activated biochars, the kinetics of adsorption of acetaminophen and amoxicillin were better described using the general order model. The isotherms of adsorption were better described by the Freundlich model (H3PO4-activated biochar) and the Langmuir model (KOH-activated biochar).

9.
Front Plant Sci ; 13: 770179, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35401605

RESUMO

Digestate from biogas production high in plant-available macro- and micro-nutrients could replace mineral fertilizer in protected (soilless) horticulture. Previous uses of digestate have shown that low concentrations of plant-available phosphorus (P) and sulfur (S) may be limiting factors for growth when using digestate as the sole fertilizer. In this study, digestate collected from a municipal biogas plant in Sweden was nitrified in a moving-bed biofilm reactor prior to its use as fertilizer. A greenhouse pot trial with pak choi grown in peat-based growing medium was established to assess the (i) macro- and micro-nutrient availability in the digestate, with particular focus on P and S and (ii) the effect of amending the digestate solution with nutrients considered to be lacking [P, S, magnesium (Mg), manganese (Mn), boron (B), and molybdenum (Mo)]. The results showed that plants fertilized with raw digestate suffered from S and B deficiency and early P deficiency. Supplementing the digestate with nutrients originating from mineral salts resulted in sufficient plant tissue concentrations of all elements except S. The marketable yield was similar to that achieved using standard mineral fertilizer and the dry matter yield was 17% higher. In the light of the present results, the use of nitrified digestate in soilless plant production seems like a fruitful way forward to recycle organic nutrients from waste streams. In the case where a strict organic protocol is not needed, amendment with inorganic nutrients may be a way to increase the utilization of organically derived nutrients.

10.
Chemosphere ; 291(Pt 2): 132898, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34780735

RESUMO

Organic micropollutants (MPs) pose potential threats to environmental ecosystems and human health. This study investigated uptake of perfluoroalkyl substances (PFASs), pharmaceuticals, and paraben by edible oyster mushrooms (Pleurotus ostreatus), cultivated on spiked growth substrate. Concentrations of pharmaceuticals and paraben in substrate showed a decreasing trend over a 20-day harvesting period, whereas PFAS concentrations were variable over the harvesting period. However, only propylparaben, clarithromycin, and PFASs were detected in fruiting bodies of oyster mushroom. Uptake of PFASs by oyster mushroom fruit bodies was negatively correlated with perfluorocarbon chain length. An impact of MPs on fungal colonization was observed, with decreased respiration in treatments with the highest concentration of MPs, but production of fruiting bodies was not affected by exposure level. The potential human risk from ingestion of MPs was evaluated for oyster mushrooms exposed to the highest concentration of MPs in substrate, based on acceptable daily intake (ADI).


Assuntos
Fluorocarbonos , Preparações Farmacêuticas , Pleurotus , Ecossistema , Humanos , Parabenos
11.
Artigo em Inglês | MEDLINE | ID: mdl-35270364

RESUMO

One of the main challenges in both the design of new wastewater treatment plants and the expansion and improvement of existing ones is the removal of emerging pollutants. Therefore, the search for economic and sustainable treatments is needed to enhance the removal of pharmaceuticals. The potential of a lignocellulosic substrate colonized by Pleurotus ostreatus, a waste from mushroom production, to remove fluoxetine from aqueous solutions was studied. Batch assays were performed to remove 600 µg∙L-1 fluoxetine from aqueous solutions using the colonized mushroom substrate (CMS) and crude enzyme extracts. The removal efficiencies achieved were, respectively, ≥83.1% and 19.6% in 10 min. Batch assays with sterilized CMS and 1-aminobenzotriazole (to inhibit cytochrome P450 enzymes) showed that the higher removal efficiencies achieved in the CMS assays may be attributed to the synergistic contribution of biosorption onto the CMS and lignin modifying enzymes activity, namely laccase activity. A column assay was performed with the CMS, fed with 750 µg∙L-1 fluoxetine aqueous solution. The removal efficiency was 100% during 30 min, decreasing to a final value of 70% after 8 h of operation. The results suggested that CMS can be a promising eco-friendly alternative to remove fluoxetine from aqueous solutions.


Assuntos
Agaricales , Pleurotus , Biodegradação Ambiental , Fluoxetina , Lacase , Lignina , Água
12.
Sci Total Environ ; 637-638: 1395-1399, 2018 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-29801232

RESUMO

Wetlands have been successfully implemented as water purification systems for removal of plant nutrients and can play a significant role in nutrient recycling, depending on use of the harvested biomass. In a constructed wetland in southern Sweden examined in this study, assimilation of plant nutrients in wetland biomass corresponded to 234 kg/ha nitrogen, 22.8 kg/ha phosphorus, and 158 kg/ha potassium in the study year (2016). The harvested biomass, composed exclusively of common reed, was evaluated as a substrate for production of oyster mushrooms, one of the most widely produced edible mushrooms in the world. The biological efficiency of the substrate was 138 ±â€¯10%, corresponding to production of 1.4 kg mushrooms (fresh weight) based on 1 kg reed (dry weight). The fruiting bodies had high quality, with total protein concentration 18.3 ±â€¯2.8% and very low levels of contaminating heavy metals. Thus, nutrient assimilation in wetland biomass not only decreases the risk of eutrophication in recipient waters, but can be utilized for direct production of high-quality food. The biomass remaining after mushroom production, composed of mycelium and partly degraded wetland biomass, has potential for use in ruminant feed, i.e., as roughage.


Assuntos
Agaricales/fisiologia , Biodegradação Ambiental , Áreas Alagadas , Biomassa , Eutrofização , Metais Pesados , Nitrogênio/análise , Fósforo/análise , Plantas , Poaceae , Reciclagem , Suécia , Eliminação de Resíduos Líquidos , Purificação da Água
13.
Chem Biol Interact ; 165(1): 54-8, 2007 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-17141750

RESUMO

BACKGROUND: Mild hyperhomocysteinemia is associated with premature vascular disease. The mechanism behind the vascular injuries is, however, still unknown. Homocysteine may be catabolized in the trans-sulfuration pathway to cysteine. Cystathionine beta-synthase, which catalyses the first step in the trans-sulfuration pathway is redox-sensitive. We have therefore investigated total extracellular homocysteine turnover in the presence of oxidative stress in human cell lines. METHODS: The turnover of total extracellular homocysteine in HeLa and hepatoma cell cultures has been investigated in the presence of hydrogen peroxide. Furthermore, the effect of hydrogen peroxide on the removal of high amounts of exogenously added homocysteine was also studied. RESULTS: Total extracellular homocysteine concentration in hepatoma cell cultures decreased in the presence of hydrogen peroxide, whereas the extracellular homocysteine concentration in HeLa cell cultures was not influenced. There was no significant change of intracellular homocysteine in any type of cell cultures. Furthermore, the presence of hydrogen peroxide did not increase the removal of exogenously added homocysteine. CONCLUSION: The presence of hydrogen peroxide probably increases the activity of the trans-sulfuration pathway in hepatoma cell cultures, which increases the intracellular use of homocysteine and lowers its extracellular release. Consequently this mechanism might tend to lower total plasma homocysteine concentration in oxidative stress.


Assuntos
Carcinoma Hepatocelular/metabolismo , Líquido Extracelular/metabolismo , Homocisteína/metabolismo , Estresse Oxidativo/fisiologia , Técnicas de Cultura de Células , Linhagem Celular Tumoral/citologia , Linhagem Celular Tumoral/efeitos dos fármacos , Linhagem Celular Tumoral/metabolismo , Líquido Extracelular/química , Células HeLa/citologia , Células HeLa/efeitos dos fármacos , Células HeLa/metabolismo , Humanos , Peróxido de Hidrogênio/farmacologia , Enxofre/metabolismo , Fatores de Tempo
14.
Chem Biol Interact ; 167(1): 56-62, 2007 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-17275800

RESUMO

BACKGROUND: Cell death induced by intracellular glutathione depletion has been reported to be dependent on the presence of trace amounts of extracellular copper ions. Since little is known about the relationship between glutathione depletion and copper homeostasis, we have in the present study further investigated the role of low amounts of copper ions in glutathione depletion. METHODS: Glutathione turnover was investigated in HeLa and hepatoma cell cultures with normal and low cysteine content in the presence of copper ions (1 and 10micromol/L) and two other glutathione-stimulating agents (lipoic acid and mercury ions). RESULTS: Copper ions (10micromol/L) caused relatively small increases in total amount of glutathione (the sum of the intracellular and the extracellular amount of glutathione) in HeLa and hepatoma cell cultures with normal cysteine levels (420nmol/mL) compared to control cell cultures, whereas lipoic acid and mercury ions strongly increased total glutathione in both types of cell cultures. Lower amount of total glutathione was observed in cell cultures with a lower cysteine levels (84nmol/mL), which is similar to that in human plasma. A strongly decreased total amount of glutathione in the presence of copper ions was observed in hepatoma cell cultures with lower cysteine levels, whereas the other agents showed effects similar to those described for cell cultures with normal cysteine levels. CONCLUSION: Glutathione synthesis in hepatoma cell cultures is probably more sensitive to a low cysteine level than HeLa cell cultures, and the presence of copper ions further decreases the availability of cysteine probably by increasing the disulfide binding to cysteine residues in extracellular proteins, which causes a further decrease of total glutathione.


Assuntos
Cobre/toxicidade , Cisteína/metabolismo , Glutationa/metabolismo , Carcinoma Hepatocelular , Linhagem Celular Tumoral , Células HeLa , Humanos , Mercúrio/farmacologia , Ácido Tióctico/farmacologia
15.
Environ Toxicol Pharmacol ; 24(1): 19-22, 2007 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21783784

RESUMO

Pesticides are widely spread in the environment and there is a lack of knowledge concerning the impact of these substances on the human cell. In the present study the effect of low doses of the pesticides bentazon, metalaxyl and glyphosate on the cellular metabolism of glutathione and cysteine was examined in HeLa and hepatoma cell cultures. No effect was observed when the cells were exposed to bentazon or metalaxyl. However, significant changes in the intra- and extracellular concentration of cysteine, a precursor for glutathione synthesis, were detected when glyphosate was added to the medium. This finding was observed in the presence of micromolar concentration range of glyphosate, and is relevant when compared to concentrations observed in monitoring programmes.

16.
Biochim Biophys Acta ; 1726(1): 42-7, 2005 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-16216418

RESUMO

BACKGROUND: We have previously shown that there were great discrepancies between different agents regarding their glutathione stimulating potential and that agents with mainly oxidative effects did not increase concentrations of glutathione in human cell cultures, in contrast to other thiol reactive agents. In order to evaluate whether increased glutathione degradation might be one reason for these discrepancies, we have investigated the effect of different agents with potential influence on glutathione metabolism in human cell cultures with or without acivicin inhibition of gamma-glutamyltranspeptidase (GT), since GT is responsible for the initial degradation of glutathione. METHODS: Intra- and extracellular concentrations of glutathione were investigated in HeLa and hepatoma cell cultures, with and without acivicin inhibition of GT, in the presence of oxidative and electrophilic agents (copper ions, hydrogen peroxide and N-ethylmaleimide), hydroquinone, reducing agents (lipoic acid and N-acetylcysteine), and a thiol reactive metal (mercury ions). RESULTS: There were great discrepancies between the different agents regarding their maximal glutathione response (the sum of the intracellular and the extracellular amount of glutathione) in cell cultures. There was only a small increase in total glutathione in the presence of hydrogen peroxide or N-ethylmaleimide before the cell protein decreased compared to findings with mercury ions, lipoic acid or hydroquinone. In both HeLa and hepatoma cell cultures, there were correlations between the original glutathione amount and the total glutathione amount observed after acivicin inhibition. CONCLUSION: The relatively small increase of glutathione amount in the presence of oxidative and electrophilic agents compared to other thiol reactive agents is not due to increased GT degradation of glutathione.


Assuntos
Glutationa/metabolismo , Isoxazóis/farmacologia , gama-Glutamiltransferase/antagonistas & inibidores , Acetilcisteína/metabolismo , Linhagem Celular Tumoral , Cobre/metabolismo , Etilmaleimida/metabolismo , Humanos , Peróxido de Hidrogênio/metabolismo , Hidroquinonas/metabolismo , Mercúrio/metabolismo , Ácido Tióctico/metabolismo
17.
Clin Biochem ; 39(2): 160-3, 2006 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16330015

RESUMO

OBJECTIVE: The metabolism of homocysteine is influenced by several dietary factors, including folate, cobalamin and possibly also the intake of polyhydroxylated phenolic compounds (polyphenols), which were shown to increase plasma homocysteine (tHcy) concentration. In order to reveal the cause of the increased plasma tHcy, we have therefore investigated the effects of a polyphenol in cell cultures from human cell lines. DESIGN AND METHODS: We have studied the influence of the polyphenol quercetin (Quer) on intra- and extracellular homocysteine concentrations in HeLa and hepatoma cell cultures. RESULTS: The main finding is an increased concentration of extracellular homocysteine in the presence of Quer in hepatoma cell cultures, whereas there were no significant changes of homocysteine concentration in HeLa cell cultures. There was no effect on cellular growth, as judged by cell protein. The presence of adenosyl-dialdehyde, an inhibitor of adenosyl-homocysteine hydrolase, abolished the increased extracellular concentration of homocysteine observed in hepatoma cell cultures in the presence of Quer. CONCLUSION: The antioxidative agent Quer strongly increased the extracellular concentration of homocysteine in hepatoma cell cultures probably due to increased cellular methylation. In the human body, the same phenomenon might lead to increased plasma tHcy. Since elevated plasma tHcy is associated with premature vascular disease, high long-lasting dietary intake of polyphenols might be harmful. The interaction between Quer and homocysteine turnover may therefore warrant a re-evaluation of polyphenols as relatively harmless antioxidative food supplements or therapeutic antioxidative agents.


Assuntos
Antioxidantes/farmacologia , Homocisteína/metabolismo , Quercetina/farmacologia , Adenosina/análogos & derivados , Adenosina/farmacologia , Adenosil-Homocisteinase/antagonistas & inibidores , Carcinoma Hepatocelular , Linhagem Celular Tumoral , Inibidores Enzimáticos/farmacologia , Células HeLa , Humanos
18.
Chem Biol Interact ; 163(3): 192-8, 2006 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-16970934

RESUMO

BACKGROUND: Glutathione plays crucial roles in antioxidant defence and glutathione deficiency contributes to oxidative stress and may therefore play a key role in the pathogenesis of many diseases. The objectives of the present study were to evaluate the effects on glutathione turnover of thiol and non-thiol antioxidants in human cell cultures and if any of the antioxidant had a short-term cellular effect against different levels of hydrogen peroxide. METHODS: We have investigated the effect on the total glutathione amount in HeLa and hepatoma cell cultures of thiol antioxidants in comparison with non-thiol antioxidants, such as a copper chelator, Vitamin C, and a flavonoid. Furthermore, we have investigated the short-term (within 24h) interaction of the different antioxidants with hydrogen peroxide. RESULTS AND CONCLUSION: Lipoic acid and quercetin (Quer) were the two antioxidants that showed the highest stimulation of glutathione synthesis in cell cultures as judged by the total glutathione amount. However, no antioxidant protected against hydrogen peroxide present in concentrations that lowered cell protein. This finding may be attributed to the fact that it is necessary to incubate cell cultures with antioxidants or small doses of oxidants for a period before the cultures are exposed to hydrogen peroxide in order to enhance the antioxidant defence. The presence of Quer and Vitamin C lowered cell protein and total glutathione even in cell cultures containing hydrogen peroxide in concentrations that did not lower cell protein. This finding might be attributed to pro-oxidant properties and formation of excess reactive oxygen species in the presence of Quer and Vitamin C.


Assuntos
Antioxidantes/farmacologia , Glutationa/metabolismo , Peróxido de Hidrogênio/farmacologia , Acetilcisteína/farmacologia , Interações Medicamentosas , Células HeLa , Humanos , Isoxazóis/farmacologia , Fenantrolinas/farmacologia , Quercetina/farmacologia , Ácido Tióctico/farmacologia
19.
Environ Technol ; 37(7): 893-8, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26370171

RESUMO

The effect of the microalgae Chlorella vulgaris on a wide range of different pesticides in water was studied. Treatments included short-term exposure (1 h) to living and dead microalgal biomass and long-term exposure (4 days) to actively growing microalgae. The initial pesticide concentration was 63.5 ± 3.9 µg L(-1). There was no significant overall reduction of pesticides after short-term exposure. A significant reduction of the total amount of pesticides was achieved after the long-term exposure to growing microalgae (final concentration 29.7 ± 1.0 µg L(-1)) compared with the long-term control (37.0 ± 1.2 µg L(-1)). The concentrations of 10 pesticides out of 38 tested were significantly lowered in the long-term algal treatment. A high impact of abiotic factors such as sunlight and aeration for pesticide reduction was observed when the initial control (63.5 ± 3.9 µg L(-1)) and the long-term control (37.0 ± 1.2 µg L(-1)) were compared. The results suggest that water treatment using microalgae, natural inhabitants of polluted surface waters, could be further explored not only for removal of inorganic nutrients but also for removal of organic pollutants in water.


Assuntos
Biodegradação Ambiental , Microalgas/metabolismo , Praguicidas/metabolismo , Poluentes Químicos da Água/metabolismo , Chlorella vulgaris/metabolismo , Praguicidas/análise , Praguicidas/isolamento & purificação , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/isolamento & purificação
20.
Bioresour Technol ; 207: 19-23, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26868151

RESUMO

Nutrient removal from the effluent of an anaerobic moving bed biofilm reactor (AnMBBR) treated with microalgae was evaluated. Algal treatment was highly efficient in removal of nutrients and discharge limits were met after 3days. Extending the cultivation time from 3 to 5days resulted in a large increase in biomass, from 233.3±49.3 to 530.0±72.1mgL(-1), despite nutrients in the water being exhausted after 3days (ammonium 0.04mgL(-1), orthophosphate <0.05mgL(-1)). Biomass productivity, lipid content and quality did not differ in microalgal biomass produced in wastewater sampled before the AnMBBR. The longer cultivation time resulted in a slight increase in total lipid concentration and a significant decrease in linolenic acid concentration in all treatments. Differences were observed in chemical oxygen demand, which decreased after algal treatment in wastewater sampled before the AnMBBR whereas it increased after algal treatment in the effluent from the AnMBBR.


Assuntos
Biofilmes , Reatores Biológicos/microbiologia , Cidades , Microalgas/crescimento & desenvolvimento , Águas Residuárias/microbiologia , Purificação da Água/métodos , Biodegradação Ambiental , Biomassa , Ésteres/análise , Lipídeos , Nitrogênio/isolamento & purificação , Fósforo/isolamento & purificação
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