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- Anasontzis, George E, 1980
(författare)
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Biomass modifying enzymes: From discovery to application
- 2012
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Ingår i: Oral presentation at the Chalmers Life Science AoA conference.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- It has now been realized that the road towards the bio-based economy is a one-way street, leaving gradually the oil-based technology and driving slowly towards a more sustainable society. The current non-biodegradable hydrocarbon fuels and plastics will be replaced by new products which will derive from natural and renewable resources. The synthesis of such biofuels and biochemicals is still challenged by the difficulties to cost efficiently degrade lignocellulosic material to fermentable sugars or to isolate the intact polymers. Biomass degrading and modifying enzymes play an integral role both in the separation of the polymers from the wood network, as well as in their subsequent modification, prior to further product development.Our group interests focus on all levels of applied enzyme research of biomass acting enzymes: Discovery, assay development, production and application. Relevant examples will be provided: What is our strategy for discovering novel microorganisms and enzymes from the tropical forests and grasslands of Vietnam? How do we design novel real-world assays for enzyme activity determination? Which are the bottlenecks in the enzymatic cellulose hydrolysis? How enzymes can be used to produce high added value compounds from biomass?
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| 3. |
- McKee, Lauren S., et al.
(författare)
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A GH115 alpha-glucuronidase from Schizophyllum commune contributes to the synergistic enzymatic deconstruction of softwood glucuronoarabinoxylan
- 2016
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Ingår i: Biotechnology for Biofuels. - : BioMed Central. - 1754-6834. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- Background: Lignocellulosic biomass from softwood represents a valuable resource for the production of biofuels and bio-based materials as alternatives to traditional pulp and paper products. Hemicelluloses constitute an extremely heterogeneous fraction of the plant cell wall, as their molecular structures involve multiple monosaccharide components, glycosidic linkages, and decoration patterns. The complete enzymatic hydrolysis of wood hemicelluloses into monosaccharides is therefore a complex biochemical process that requires the activities of multiple degradative enzymes with complementary activities tailored to the structural features of a particular substrate. Glucuronoarabinoxylan (GAX) is a major hemicellulose component in softwood, and its structural complexity requires more enzyme specificities to achieve complete hydrolysis compared to glucuronoxylans from hardwood and arabinoxylans from grasses. Results: We report the characterisation of a recombinant alpha-glucuronidase (Agu115) from Schizophyllum commune capable of removing (4-O-methyl)-glucuronic acid ((Me) GlcA) residues from polymeric and oligomeric xylan. The enzyme is required for the complete deconstruction of spruce glucuronoarabinoxylan (GAX) and acts synergistically with other xylan-degrading enzymes, specifically a xylanase (Xyn10C), an alpha-l-arabinofuranosidase (AbfA), and a beta-xylosidase (XynB). Each enzyme in this mixture showed varying degrees of potentiation by the other activities, likely due to increased physical access to their respective target monosaccharides. The exo-acting Agu115 and AbfA were unable to remove all of their respective target side chain decorations from GAX, but their specific activity was significantly boosted by the addition of the endo-Xyn10C xylanase. We demonstrate that the proposed enzymatic cocktail (Agu115 with AbfA, Xyn10C and XynB) achieved almost complete conversion of GAX to arabinofuranose (Araf), xylopyranose (Xylp), and MeGlcA monosaccharides. Addition of Agu115 to the enzymatic cocktail contributes specifically to 25 % of the conversion. However, traces of residual oligosaccharides resistant to this combination of enzymes were still present after deconstruction, due to steric hindrances to enzyme access to the substrate. Conclusions: Our GH115 alpha-glucuronidase is capable of finely tailoring the molecular structure of softwood GAX, and contributes to the almost complete saccharification of GAX in synergy with other exo- and endo-xylan-acting enzymes. This has great relevance for the cost-efficient production of biofuels from softwood lignocellulose.
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| 6. |
- Anasontzis, George E, 1980, et al.
(författare)
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Screening the tropical fungal biodiversity of Vietnam for biomass modifying enzymes, with secretome and transcriptome analyses
- 2013
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Ingår i: 27th Fungal Genetics Conference.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- In the bio-based economy concept, the current hydrocarbon fuels and non-biodegradable plastics will be replaced by new products which will derive from natural and renewable resources. The synthesis of such biofuels and biochemicals is still challenged by the difficulties to cost efficiently degrade lignocellulosic materials to fermentable sugars or to isolate the intact polymers. Biomass degrading and modifying enzymes play an integral role both in the separation of the polymers from the wood network, as well as in subsequent modifications, prior to further product development. The type of application usually defines the conditions where the reactions should take place. Thus, novel enzymes with variable combined properties, such as different thermotolerance, pH range of activity, substrate specificity and solvent tolerance, still need to be discovered and developed to achieve the highest possible efficiency in each occasion. We took advantage of the rapidly evolving and high biodiversity of the tropics and have been screening various isolates for their cellulases and hemicellulases activities. Promising strains were then cultivated in bioreactors with different carbon sources, such as wheat bran, spruce and avicel and their biomass degrading capacity was analysed through cross species protein identification of their secretome with TMT. Information on the genes involved in the different stages of the fermentation and the carbon source will be acquired with next generation sequencing of the total transcriptome. Interesting transcripts will then be used to heterologously clone and express the respective genes and identify their role in the degradation process.
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| 8. |
- Anasontzis, George E, 1980, et al.
(författare)
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Enzyme Discovery Platform
- 2012
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Ingår i: WWSC annual conference, 21-23 November 2012, Uddevalla, Sweden.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Biomass treatment for the separation of its components and the modification of their properties requires a wide range of enzymes. Efficiency matters too, so multiple enzymes of the same activity need to be tested before they can be applied in a larger scale. We have launched the implementation of a strategic plan for the discovery of novel enzymes, starting from the isolation of new fungal strains from Vietnam and leading to the cloning and characterization of the enzymes of interest.
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| 10. |
- Anasontzis, George E, 1980, et al.
(författare)
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Screening Natural Resources for Enzymes With Wood Degrading and Wood Modifying Properties
- 2011
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Ingår i: Italic6/COST conference, 5–8 September 2011, Viterbo, Italy.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The production of high added value compounds from forest and agricultural biomass has become one of the main targets of contemporary carbohydrates research. The renewability of the biomass, the potential use of waste residues and the complete or partial biodegradability of the products have made the whole approach an attractive perspective towards the sustainable and green ideal. However, most of the already developed biomass separation and modification processes are based on chemical reactions at extreme conditions that are costly and often harmful for the environment. Enzymatic and microbial catalyzed processes present an interesting alternative. The development and discovery of novel biological approaches in the modification, degradation and separation of wood biomass is one of the main activities of the Industrial Biotechnology Group at Chalmers University of Technology, also as part of the Wallenberg Wood Science Center (WWSC).Presently, we pursue this aim through a triple approach: •Μultiple enzymatic screening of phytopathogenic and wood degrading filamentous fungi, such as Trametes hirsuta and Penicillium pinophilum, as well as screening newly isolated microorganisms. We seek enzymes with industrially interesting activities and unique properties, such as reactivity under extreme conditions.•Microorganisms efficient in degrading lignocellulose produce enzyme in response to the environmental conditions. In collaboration with Associate Professor Gianni Panagiotou, Center for Biological Sequence Analysis, DTU, we are looking for sequenced, but still unclassified proteins, which are related to the degradation of plant biomass using information from transcriptomics analysis of Aspergillus oryzae grown on different carbon sources.•Novel enzymes can only be identified by new methods. We investigate the properties of synthetic model compounds that can simulate the natural substrates and the implementation of different analytical methods for the identification of the sometimes complex and singular enzymatic activities. In collaboration with Associate Professor Paul Christakopoulos, BIOtechMASS Unit, School of Chemical Engineering, National Technical University of Athens, we also attempt to isolate model compounds from plant cell wall material.
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