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| 2. |
- Hultberg, M., et al.
(författare)
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Fungi-based treatment of brewery wastewater-biomass production and nutrient reduction
- 2017
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Ingår i: Applied Microbiology and Biotechnology. - : Springer Verlag (Germany). - 0175-7598 .- 1432-0614. ; 101:11, s. 4791-4798
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Tidskriftsartikel (refereegranskat)abstract
- The beer-brewing process produces high amounts of nutrient-rich wastewater, and the increasing number of microbreweries worldwide has created a need for innovative solutions to deal with this waste. In the present study, fungal biomass production and the removal of organic carbon, phosphorus and nitrogen from synthetic brewery wastewater were studied. Different filamentous fungi with a record of safe use were screened for growth, and Trametes versicolor, Pleurotus ostreatus and Trichoderma harzianum were selected for further work. The highest biomass production, 1.78 ± 0.31 g L(-1) of dry weight, was observed when P. ostreatus was used for the treatment, while T. harzianum demonstrated the best capability for removing nutrients. The maximum reduction of chemical oxygen demand, 89% of the initial value, was observed with this species. In the removal of total nitrogen and phosphorus, no significant difference was observed between the species, while removal of ammonium varied between the strains. The maximum reduction of ammonium, 66.1% of the initial value, was also found in the T. harzianum treatment. It can be concluded that all treatments provided significant reductions in all water-quality parameters after 3 days of growth and that the utilisation of filamentous fungi to treat brewery wastewater, linked to a deliberate strategy to use the biomass produced, has future potential in a bio-based society.
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| 3. |
- Hultberg, M, et al.
(författare)
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Fungi-based treatment of real brewery waste streams and its effects on water quality
- 2019
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Ingår i: Bioprocess and biosystems engineering (Print). - : Springer Verlag (Germany). - 1615-7591 .- 1615-7605. ; 42:8, s. 1317-1324
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Tidskriftsartikel (refereegranskat)abstract
- Nutrient-rich liquid waste streams generated during the beer brewing were treated by submerged fungal growth. Among five filamentous fungal strains tested, Pleurotus ostreatus and Trichoderma harzianum were selected for treatment of run-off from spent grain and hot trub, respectively. In both waste streams, nitrogen was well removed by fungal treatment, with a maximum reduction of 91.5 ± 0.5% of total nitrogen in run-off from spent grain treated with P. ostreatus and 77.0 ± 3.1% in hot trub treated with T. harzianum. Removal of phosphorus was considerably lower, with maximum removal of total phosphorus of 30.8 ± 11.1% for the P. ostreatus treatment and 16.6 ± 7.8% for the T. harzianum treatment. Considering the high concentration of phosphorus in the waste sources (320-600 mg L-1), additional techniques for its removal are needed. In the P. ostreatus treatment, a total amount of 13.2 ± 2.2 g L-1 dwt of biomass with a protein concentration of 11.6 ± 2.1% was produced.
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| 4. |
- Hultberg, Malin, et al.
(författare)
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Glutathione turnover in human cell lines in the presence of agents with glutathione influencing potential with and without acivicin inhibition of gamma-glutamyltranspeptidase.
- 2005
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Ingår i: Biochimica et Biophysica Acta. General Subjects. - : Elsevier BV. - 0304-4165. ; 1726:1, s. 42-47
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Tidskriftsartikel (refereegranskat)abstract
- 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), hydroquitione, 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.
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| 5. |
- Hultberg, Malin, et al.
(författare)
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Oxidative stress decreases extracellular homocysteine concentration in human hepatoma (HepG2) cell cultures
- 2007
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Ingår i: Chemico-Biological Interactions. - : Elsevier BV. - 1872-7786 .- 0009-2797. ; 165:1, s. 54-58
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Tidskriftsartikel (refereegranskat)abstract
- 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 transsulfuration 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 transsulfuration 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. (c) 2006 Elsevier Ireland Ltd. All rights reserved.
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| 6. |
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| 7. |
- Hultberg, Malin, et al.
(författare)
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The polyphenol quercetin strongly increases homocysteine production in a human hepatoma (Hep G2) cell line.
- 2006
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Ingår i: Clinical Biochemistry. - : Elsevier BV. - 1873-2933 .- 0009-9120. ; 39:2, s. 160-163
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Tidskriftsartikel (refereegranskat)abstract
- 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. (c) 2005 The Canadian Society of Clinical Chemists. All rights reserved.
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| 8. |
- Hultberg, Malin, et al.
(författare)
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Traces of copper ions deplete glutathione in human hepatoma cell cultures with low cysteine content
- 2007
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Ingår i: Chemico-Biological Interactions. - : Elsevier BV. - 1872-7786 .- 0009-2797. ; 167:1, s. 56-62
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Tidskriftsartikel (refereegranskat)abstract
- Background: Cell death induced by intracellutar 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 10 mu mol/L) and two other glutathione-stimulating agents (lipoic acid and mercury ions). Results: Copper ions (10 mu mol/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 (420 nmol/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 (84 nmol/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 disultide binding to cysteine residues in extracellular proteins, which causes a further decrease of total glutathione. (c) 2007 Elsevier Ireland Ltd. All rights reserved.
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| 9. |
- Alam, Mehboob, et al.
(författare)
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Prevalence of Escherichia coli O157:H7 on spinach and rocket as affected by inoculum and time to harvest
- 2014
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Ingår i: Scientia Horticulturæ. - : Elsevier BV. - 0304-4238 .- 1879-1018. ; 165, s. 235-241
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Tidskriftsartikel (refereegranskat)abstract
- Irrigation water is an important vehicle for dissemination of human pathogens to plants. As contamination in an early stage of the production chain cannot necessarily be counteracted later, cultural measures to reduce the contamination risk need to be adopted during primary production. In a two-factorial greenhouse experiment, we studied the impact of inoculum density and the interval between irrigation and haivest on the prevalence of an inoculated gfp-tagged non-pathogenic strain of Escherichia coli O157:H7. The strain was inoculated with the irrigation water at a density of log 5.6, log 6.6 and log 7.6 CFU ml(-1) into the phyllosphere of fully grown crops of rocket and spinach (BBCH 49). The crops were then harvested after 3, 24,48 and 72 h. The introduced strain decreased exponentially in numbers within 72 h, to 49.6%, 52.6% and 50.6%, respectively, in the spinach and to 58.5%, 67.4% and 73.4% in the rocket. No differences were found in the number of the total viable count of aerobic bacteria and of Enterobacteriaceae as assessed on tryptic soy agar (TSA) and violet red bile dextrose agar (VRBD), respectively. Sequencing of the 16S rRNA genes of randomly selected isolates from VRBD were identified as Enterobacter cloaceae, Enterobacter ludwigii, Pantoea sp. and Raoultella planticola as the dominant Enterobacteriaceae species in the rocket and spinach phyllosphere. We found that cessation of irrigation for three days seems not to be an adequate sanitisation treatment to exclude the possibility of viable E. coil 0157:H7 cells on spinach or rocket. (C) 2013 Elsevier B.V. All rights reserved.
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| 10. |
- Alsanius, Beatrix, et al.
(författare)
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Bedömning av markens mikroliv
- 2024
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Ingår i: LTV-fakultetens faktablad.
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Annan publikation (populärvet., debatt m.m.)
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