| 1. |
- Kittler, Stefan, et al.
(författare)
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Recombinant Protein L: Production, Purification and Characterization of a Universal Binding Ligand
- 2022
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Ingår i: Journal of Biotechnology. - : Elsevier BV. - 1873-4863 .- 0168-1656. ; 359, s. 108-115
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Tidskriftsartikel (refereegranskat)abstract
- Protein L (PpL) is a universal binding ligand that can be used for the detection and purification of antibodies and antibody fragments. Due to the unique interaction with immunoglobulin light chains, it differs from other affinity ligands, like protein A or G. However, due to its current higher market price, PpL is still scarce in applications. In this study, we investigated the recombinant production and purification of PpL and characterized the product in detail. We present a comprehensive roadmap for the production of the versatile protein PpL in E. coli.
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| 2. |
- Nordell, Erik, et al.
(författare)
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Thermal post-treatment of digestate in order to increase biogas production with simultaneous pasteurization
- 2022
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Ingår i: Journal of Biotechnology. - : Elsevier. - 0168-1656 .- 1873-4863. ; :344, s. 32-39
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Tidskriftsartikel (refereegranskat)abstract
- Biogas production by anaerobic digestion (AD) of organic wastes is important for the transition to fossil free fuelsin both the transport sector, industries and shipping. The aim of this study was to target the residual organicmatter in the outgoing residue from the AD process, so called digestate, with different thermal treatmentmethods in order to improve digestate degradability and biogas potential upon post-digestion. The thermaltreatment was performed at 55 ◦C in 24 h, 70 ◦C in 1 h and by thermal hydrolysis process (THP; 165 ◦C, 8 bar in0.33 h), and were carefully selected to offer a simultaneous possibility for pasteurization of the digestate accordingto the regulations in Sweden. Digestates from ten full-scale biogas plants were collected, with differentsubstrate profiles including wastewater treatment plant (WWTP), food waste digestion, agriculture digestion andmanure digestion. The results showed that all thermal treatment methods caused increased dissolved organiccarbon concentration (DOC). Four of the thermal treated digestates with the highest increase in DOC weresubsequently tested for the bio-methane potential. Thermal treatments at 70 ◦C and THP, respectively, resulted inthe highest increase in bio-methane potentials, with an increase of 15–39% for one WWTP, 38 – 40% fordigestate from an agriculture digestion plant and 20 – 22% for digestate from a co-digestion plant treating foodwaste. Interestingly, the bio-methane potential from digestate treated with the energy-intense THP method, didnot show any significant difference compared to thermal treatment at 70 ◦C for 1 h. The outcomes of this studysuggest that placing a pasteurization unit between a main digester and a post digester, when applying two-stepdigestion allows for a combined pasteurization and increased biogas production.
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| 3. |
- Park, Yu Rim, et al.
(författare)
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Enhancement of catabolite regulatory genes in Saccharomyces cerevisiae to increase ethanol production using hydrolysate from red seaweed Gloiopeltis furcata
- 2021
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Ingår i: Journal of Biotechnology. - : Elsevier BV. - 0168-1656 .- 1873-4863. ; 333, s. 1-9
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Tidskriftsartikel (refereegranskat)abstract
- Glucose and galactose are monosaccharides obtained from Gloiopeltis furcata (Red algae). A total monosaccharide yield of 62.3 g/L was obtained from G. furcata using thermal acid hydrolysis and enzymatic saccharification. Activated carbon was used to eliminate hydroxymethylfurfural (HMF) from the hydrolysate. Previously obtained monosaccharides are used for ethanol production by Saccharomyces cerevisiae. S. cerevisiae consumes glucose first, then galactose. The methods for reducing fermentation time and increasing the ethanol yield coefficient using the simultaneous consumption of glucose and galactose have been evaluated. Gal3p and Gal80p of S. cerevisiae act as signal transducers that govern the galactose inducer Gal4p mediated transcriptional activation of the Gal gene family. Gal80p binds to Gal4p for transcription deactivation. Therefore, Gal80p was deleted for Gal4p expression without interruption.
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| 4. |
- Schwarz, Hubert, et al.
(författare)
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Small-scale bioreactor supports high density HEK293 cell perfusion culture for the production of recombinant Erythropoietin
- 2020
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Ingår i: Journal of Biotechnology. - : Elsevier. - 0168-1656 .- 1873-4863. ; 309, s. 44-52
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Tidskriftsartikel (refereegranskat)abstract
- Process intensification in mammalian cell culture-based recombinant protein production has been achieved by high cell density perfusion exceeding 10(8) cells/mL in the recent years. As the majority of therapeutic proteins are produced in Chinese Hamster Ovary (CHO) cells, intensified perfusion processes have been mainly developed for this type of host cell line. However, the use of CHO cells can result in non-human posttranslational modifications of the protein of interest, which may be disadvantageous compared with human cell lines. In this study, we developed a high cell density perfusion process of Human Embryonic Kidney (HEK293) cells producing recombinant human Erythropoietin (rhEPO). Firstly, a small-scale perfusion system from commercial bench-top screening bioreactors was developed for < 250 mL working volume. Then, after the first trial runs with CHO cells, the system was modified for HEK293 cells (more sensitive than CHO cells) to achieve a higher oxygen transfer under mild aeration and agitation conditions. Steady states for medium (20 x 10(6) cells/mL) and high cell densities (80 x 10(6) cells/mL), normal process temperature (37 degrees C) and mild hypothermia (33 degrees C) as well as different cell specific perfusion rates (CSPR) from 10 to 60 pL/cell/day were applied to study the performance of the culture. The volumetric productivity was maximized for the high cell density steady state but decreased when an extremely low CSPR of 10 pL/cell/day was applied. The shift from high to low CSPR strongly reduced the nutrient uptake rates. The results from our study show that human cell lines, such as HEK293 can be used for intensified perfusion processes.
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| 5. |
- Ulfenborg, Benjamin, 1985-, et al.
(författare)
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Multi-Assignment Clustering : Machine learning from a biological perspective
- 2021
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Ingår i: Journal of Biotechnology. - : Elsevier. - 0168-1656 .- 1873-4863. ; 326, s. 1-10
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Tidskriftsartikel (refereegranskat)abstract
- A common approach for analyzing large-scale molecular data is to cluster objects sharing similar characteristics. This assumes that genes with highly similar expression profiles are likely participating in a common molecular process. Biological systems are extremely complex and challenging to understand, with proteins having multiple functions that sometimes need to be activated or expressed in a time-dependent manner. Thus, the strategies applied for clustering of these molecules into groups are of key importance for translation of data to biologically interpretable findings. Here we implemented a multi-assignment clustering (MAsC) approach that allows molecules to be assigned to multiple clusters, rather than single ones as in commonly used clustering techniques. When applied to high-throughput transcriptomics data, MAsC increased power of the downstream pathway analysis and allowed identification of pathways with high biological relevance to the experimental setting and the biological systems studied. Multi-assignment clustering also reduced noise in the clustering partition by excluding genes with a low correlation to all of the resulting clusters. Together, these findings suggest that our methodology facilitates translation of large-scale molecular data into biological knowledge. The method is made available as an R package on GitLab (https://gitlab.com/wolftower/masc).
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| 6. |
- Andreasson, Linnea, et al.
(författare)
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Differentiation of induced pluripotent stem cells into definitive endoderm on Activin A-functionalized gradient surfaces
- 2021
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Ingår i: Journal of Biotechnology. - : Elsevier BV. - 0168-1656. ; 325:January, s. 173-178
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Tidskriftsartikel (refereegranskat)abstract
- Activin A plays a central role in the differentiation of stem cells into definitive endoderm, the first step in embryonic development and function development in many organ systems. The aims of this study were to induce controlled and fine-tuned cell differentiation using a gradient nanotechnology and compare this with a classic protocol and to investigate how induced pluripotent stem cells differentiated depending on the gradual increase of Activin A. The density difference was tested by attaching Activin A to a gold nanoparticle gradient for high-precision density continuity. Cells expressed the definitive endoderm markers SRY-box transcription factor 17 and transcription factor GATA-4 to different extents along the gradient, indicating a density-dependent cell response to Activin A. In both the gradient and the classic differentiation setups, the protein expression increased from days 1 to 5, but a significant increase already on day 3 was found only in the gradient-based setup. By utilizing the gradient technology to present the right amount of active biomolecules to cells in vitro, we were able to find an optimal setting for differentiation into definitive endoderm. The use of gradient surfaces for differentiation allows for improvements, such as efficiency and faster differentiation, compared with a classic protocol. © 2020 Elsevier B.V.
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| 7. |
- Campos, Joana, et al.
(författare)
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Optically pure lactic acid production from softwood-derived mannose by Pediococcus acidilactici
- 2021
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Ingår i: Journal of Biotechnology. - : Elsevier BV. - 0168-1656. ; 335, s. 1-8
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Tidskriftsartikel (refereegranskat)abstract
- Softwood is of interest as a renewable carbon source for production of lactic acid. Softwood hydrolysate contains a high content of mannose. Lactic acid production from mannose by two modified strains, L-lactic acid producing Pediococcus acidilactici TY112 and D-lactic acid producing ZP26, was investigated in the current work. The two strains efficiently converted mannose to L- and D-lactate isomers with an optical purity exceeding 99 %, although the mannose utilization rates were lower than the glucose utilization rates. The mannose conversion to L- and D-lactic acids by P. acidilactici was also confirmed in dilute spruce hemicellulose hydrolysate. The present study provides important knowledge on utilization of the spectrum of fermentable sugars in softwood for future production of chiral lactic acid from lignocellulose feedstocks.
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| 8. |
- Ngo, Ngoc T.N., et al.
(författare)
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Efficient laccase/TEMPO oxidation of alkyl glycosides : Effects of carbohydrate group and alkyl chain length
- 2020
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Ingår i: Journal of Biotechnology: X. - : Elsevier BV. - 2590-1559 .- 0168-1656. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- Alkyl glycosides with long hydrophobic chains have attractive surfactant properties, but their wider application is hampered by their low solubility in water. Here, a route to increased solubility by introduction of carboxyl groups via laccase/TEMPO oxidation is presented. The oxidation pathways for dodecyl β-maltoside and hexadecyl β-maltoside were studied in detail. Close to full conversion was achieved for both substrates and conditions were found under which the diacid products dominated, with only minor amounts of under-oxidized and over-oxidized products. Dodecyl β-maltoside oxidation was improved to give a yield of 85 % of the diacid derivative. Interestingly, in spite of low substrate solubility the oxidation of hexadecyl β-maltoside was very efficient in aqueous medium, due to the higher solubility of the products. Addition of organic cosolvents did not provide additional advantages. The method is promising for producing soluble anionic derivatives of alkyl glycosides in an environmentally friendly and efficient way.
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| 9. |
- Winterling, Jeanette, et al.
(författare)
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Worries and Psychological Well-Being in Potential Hematopoietic Stem Cell Donors Before Donation-A Swedish National Study
- 2023
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Ingår i: Transplantation Proceedings. - : Elsevier. - 0041-1345 .- 1873-2623. ; 55:1, s. 242-248
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Tidskriftsartikel (refereegranskat)abstract
- Background. The physical risks involved in donating hematopoietic stem cells have been thoroughly studied, but little is known about the psychological risks potential donors might face before donation. The aim of this study was to describe potential the pre-donation worries and psychological well-being of hematopoietic stem cell donors and investigate possible associations between donor characteristics and psychological well-being.Methods. In a cross-sectional, national cohort study, we describe pre-donation worries and psychological well-being and investigate possible associations between donor characteristics and psychological well-being. A questionnaire was sent to prospective adult hematopoietic stem cells donors.Results. The study included 210 participants, 47% of whom were related and 53% unrelated to the recipient. Of the participants, 39% reported great worry about the recipient and 12% great worry about themselves as potential donors. Symptoms of anxiety were expressed by 21%, whereas symptoms of depression were uncommon and perceived general mental health was slightly lower than in the Swedish population. Great worry about oneself, lower age, and female sex were related to increased anxiety and lower mental health.Conclusion. This study highlighted that some potential donors report high levels of pre -dona-tion worry and that greater worry about oneself, lower age, and female sex are associated with lower psychological well-being. Although further studies are needed to investigate this psycho-logical risk over time, it is clear that some potential donors are particularly vulnerable.
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