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- Trydeman Knudsen, Marie, et al.
(författare)
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Characterization factors for land use impacts on biodiversity in life cycle assessment based on direct measures of plant species richness in European farmland in the ‘Temperate Broadleaf and Mixed Forest`.
- 2017
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Ingår i: Science of the Total Environment. - : Elsevier BV. - 0048-9697 .- 1879-1026. ; 580, s. 358-366
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Tidskriftsartikel (refereegranskat)abstract
- Life Cycle Assessment (LCA) is a widely used tool to assess environmental sustainability of products. The LCAshould optimally cover themost important environmental impact categories such as climate change, eutrophicationand biodiversity. However, impacts on biodiversity are seldom included in LCAs due tomethodological limitationsand lack of appropriate characterization factors. When assessing organic agricultural products theomission of biodiversity in LCA is problematic, because organic systems are characterized by higher species richnessat field level compared to the conventional systems. Thus, there is a need for characterization factors to estimateland use impacts on biodiversity in life cycle assessment that are able to distinguish between organic andconventional agricultural land use that can be used to supplement and validate the few currently suggested characterization factors. Based on a unique dataset derived fromfield recording of plant species diversity in farmlandacross six European countries, the present study provides newmidpoint occupation Characterization Factors(CF) expressing the Potentially Disappeared Fraction (PDF) to estimate land use impacts on biodiversity in the‘Temperate Broadleaf and Mixed Forest’ biome in Europe. The method is based on calculation of plant specieson randomly selected test sites in the biome and enables the calculation of characterization factors that are sensitiveto particular types ofmanagement.While species richness differs between countries, the calculated CFs areable to distinguish between different land use types (pastures (monocotyledons or mixed), arable land andhedges) and management practices (organic or conventional production systems) across countries. The new occupationCFs can be used to supplement or validate the fewcurrent CF's and can be applied in LCAs of agriculturalproducts to assess land use impacts on species richness in the ‘Temperate Broadleaf and Mixed Forest’ biome.
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| 2. |
- Lopez, J., et al.
(författare)
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Production of beta-ionone by combined expression of carotenogenic and plant CCD1 genes in Saccharomyces cerevisiae
- 2015
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Ingår i: Microbial Cell Factories. - : Springer Science and Business Media LLC. - 1475-2859. ; 14:1, s. Art. no. 84-
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Tidskriftsartikel (refereegranskat)abstract
- Background: Apocarotenoids, like the C13-norisoprenoids, are natural compounds that contribute to the flavor and/or aroma of flowers and foods. They are produced in aromatic plants-like raspberries and roses-by the enzymatic cleavage of carotenes. Due to their pleasant aroma and flavour, apocarotenoids have high commercial value for the cosmetic and food industry, but currently their production is mainly assured by chemical synthesis. In the present study, a Saccharomyces cerevisiae strain that synthesizes the apocarotenoid beta-ionone was constructed by combining integrative vectors and high copy number episomal vectors, in an engineered strain that accumulates FPP. Results: Integration of an extra copy of the geranylgeranyl diphosphate synthase gene (BTS1), together with the carotenogenic genes crtYB and crtI from the ascomycete Xanthophyllomyces dendrorhous, resulted in carotenoid producing cells. The additional integration of the carotenoid cleavage dioxygenase gene from the plant Petunia hybrida (PhCCD1) let to the production of low amounts of beta-ionone (0.073 +/- 0.01 mg/g DCW) and changed the color of the strain from orange to yellow. The expression of the crtYB gene from a high copy number plasmid in this former strain increased beta-ionone concentration fivefold (0.34 +/- 0.06 mg/g DCW). Additionally, the episomal expression of crtYB together with the PhCCD1 gene in the same vector resulted in a final 8.5-fold increase of beta-ionone concentration (0.63 +/- 0.02 mg/g DCW). Batch fermentations with this strain resulted in a final specific concentration of 1 mg/g DCW at 50 h, which represents a 15-fold increase. Conclusions: An efficient beta-ionone producing yeast platform was constructed by combining integrative and episomal constructs. By combined expression of the genes BTS1, the carotenogenic crtYB, crtI genes and the plant PhCCD1 gene-the highest beta-ionone concentration reported to date by a cell factory was achieved. This microbial cell factory represents a starting point for flavor production by a sustainable and efficient process that could replace current methods.
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