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- Knutsson, Pavleta, 1980, et al.
(författare)
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Phycoremediation of heavy metals
- 2016
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Ingår i: Energy and Clean Technologies Conference Proceedings, Sgem 2016, Vol I. - 9786197105636 ; , s. 533-540
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Konferensbidrag (refereegranskat)abstract
- Increasing amounts of heavy metals is a growing societal problem. By using ion exchangers, heavy metals can be captured and thereby their environmental impact can be decreased. Microalgae have been shown to adsorb metals; the algal cell wall contains functional groups, such as amino-, carboxyl-, hydroxyl- and sulphate groups, to which the various metal ions could bind [1]. This makes them suitable as a sustainable alternative for environmental remediation. Removal of pollutants with algae is called phycoremediation and is well studied for e.g. waste water [2]. Within this project, we study the potential of microalgae for remediating heavy metals in low concentration originating from leaching of combustion ashes, by measuring the metal binding capacity by three phytoplankton species: Chlorella sauna, Dunaliella sauna and Scendesmus obliquus. The heavy metals assessed are divalent ions of copper (Cu), cadmium (Cd), zinc (Zn), mercury (Hg) and lead (Pb). The effect of pH has been determined, as well as binding over time.
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| 5. |
- Dinér, Peter, 1976, et al.
(författare)
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Design, synthesis, and characterization of a highly effective Hog1 inhibitor: a powerful tool for analyzing MAP kinase signaling in yeast.
- 2011
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Ingår i: PloS one. - : Public Library of Science (PLoS). - 1932-6203. ; 6:5
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Tidskriftsartikel (refereegranskat)abstract
- The Saccharomyces cerevisiae High-Osmolarity Glycerol (HOG) pathway is a conserved mitogen-activated protein kinase (MAPK) signal transduction system that often serves as a model to analyze systems level properties of MAPK signaling. Hog1, the MAPK of the HOG-pathway, can be activated by various environmental cues and it controls transcription, translation, transport, and cell cycle adaptations in response to stress conditions. A powerful means to study signaling in living cells is to use kinase inhibitors; however, no inhibitor targeting wild-type Hog1 exists to date. Herein, we describe the design, synthesis, and biological application of small molecule inhibitors that are cell-permeable, fast-acting, and highly efficient against wild-type Hog1. These compounds are potent inhibitors of Hog1 kinase activity both in vitro and in vivo. Next, we use these novel inhibitors to pinpoint the time of Hog1 action during recovery from G(1) checkpoint arrest, providing further evidence for a specific role of Hog1 in regulating cell cycle resumption during arsenite stress. Hence, we describe a novel tool for chemical genetic analysis of MAPK signaling and provide novel insights into Hog1 action.
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| 8. |
- Hellström, Andreas, 1980, et al.
(författare)
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Secretion of non-cell-bound phytase by the yeast Pichia kudriavzevii TY13
- 2015
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Ingår i: Journal of Applied Microbiology. - : Oxford University Press (OUP). - 1365-2672 .- 1364-5072. ; 118:5, s. 1126-1136
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Tidskriftsartikel (refereegranskat)abstract
- AimsMineral deficiencies cause several health problems in the world, especially for populations consuming cereal-based diets rich in the anti-nutrient phytate. Our aim was to characterize the phytate-degrading capacity of the yeast Pichia kudriavzevii TY13 and its secretion of phytase. Methods and ResultsThe phytase activity in cell-free supernatants from cultures with 100% intact cells was 35-190mUml(-1) depending on the media. The K-m was 028mmoll(-1) and the specific phytase activity 032Umg(-1) total protein. The phytase activity and secretion of extracellular non-cell-bound phytase was affected by the medium phosphate concentrations. Further, addition of yeast extract had a clearly inducing effect, resulting in over 60% of the cultures total phytase activity as non-cell-bound. ConclusionsOur study reveals that it is possible to achieve high extracellular phytase activity from the yeast P.kudriavzevii TY13 by proper composition of the growth medium. Significance and Impact of the StudyTY13 could be a promising future starter culture for fermented foods with improved mineral bioavailability. Using strains that secrete phytase to the food matrix may significantly improve the phytate degradation by facilitating the enzyme-to-substrate interaction. The secreted non-cell-bound phytase activities by TY13 could further be advantageous in industrial production of phytase.
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| 9. |
- Knutsson, Pavleta, 1980, et al.
(författare)
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Phycoremediation of heavy metals in ashes
- 2014
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Ingår i: Chalmers Life Science Area of Advance Meeting, May 5, Göteborg.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- A growing problem in today’s society is the increasing amount of ash from the production of electricity and heat. Ash contains heavy metals that may be harmful to the environment. By using algae as ion exchangers, the ashes can be purified from certain heavy metals before deposit and its environmental impact is decreased [1]. Algal cell wall contains functional groups, such as amino-, carboxyl-, hydroxyl- and suphate groups, to which the various metal ions can bind bind [3]. An ion exchange of bound metal ions toward heavy metal ions can occur when the cell wall comes in contact with, for example, leachate from the ashes [1]. The process of using algae for environmental remediation is called phycoremediation.Within this project, we study the potential of microalgae for remediating ash from heavy metals, by measuring the metal binding capacity by three phytoplankton species: Chlorella salina, Dunaliella salina and Scendesmus obliquus. The heavy metals assayed are divalent ions of mercury (Hg), cadmium (Cd), copper (Cu), lead (Pb), zinc (Zn). The effect of pH has been investigated as well as total binding over time. To apply the method on a more authentic situation, the binding of metals from combustion ash was investigated.
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- Ljungdahl, Thomas, 1974, et al.
(författare)
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Positional Scanning Peptide Libraries for Kinase Substrate Specificity Determinations: Straightforward and Reproducible Synthesis Using Pentafluorophenyl Esters.
- 2010
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Ingår i: Journal of combinatorial chemistry. - : American Chemical Society (ACS). - 1520-4774 .- 1520-4766. ; 12:5, s. 733-742
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Tidskriftsartikel (refereegranskat)abstract
- An efficient method to synthesize positional scanning synthetic combinatorial libraries (PS-SCLs) for studying the specificity of protein kinases is presented. Isokinetic ratios for pentafluorophenyl esters were determined iteratively using a new approach incorporating high performance liquid chromatography (HPLC) quantification and statistical experimental design. In the development process a large amount of work was put in to find efficient ways of screening for new isokinetic mixtures and to optimize the process of PS-SCL synthesis. The newly developed methods for the screening of isokinetic mixtures could be used for the screening of other interesting mixtures, but more importantly, the isokinetic ratios determined for the preactivated pentafluorophenyl esters were incorporated into a new efficient protocol. This straightforward protocol allows for a convenient synthesis of high quality PS-SCLs regardless of previous experience in solid phase synthesis.
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