| 1. |
- Börner, Rosa Aragão
(författare)
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Isolation and cultivation of anaerobes
- 2016
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Ingår i: Advances in Biochemical Engineering/Biotechnology. - Cham : Springer International Publishing. - 0724-6145. ; 156
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Bokkapitel (refereegranskat)abstract
- Anaerobic microorganisms play important roles in different biotechnological processes. Their complex metabolism and special cultivation requirements have led to less isolated representatives in comparison to their aerobic counterparts. In view of that, the isolation and cultivation of anaerobic microorganisms is still a promising venture, and conventional methodologies as well as considerations and modifications are presented here. An insight into new methodologies and devices as well as a discussion on future perspectives for the cultivation of anaerobes may open the prospects of the exploitation of these microorganisms as a source for biotechnology.
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| 2. |
- Chen, Yun, 1978, et al.
(författare)
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Enabling Technologies to Advance Microbial Isoprenoid Production
- 2015
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Ingår i: Advances in Biochemical Engineering/Biotechnology. - Cham : Springer International Publishing. - 0724-6145 .- 1616-8542. ; 148, s. 143-160
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Tidskriftsartikel (refereegranskat)abstract
- Microbial production of isoprenoids provides an attractive alternative to biomass extraction and chemical synthesis. Although widespread research aims for isoprenoid biosynthesis, it is still in its infancy in terms of delivering commercial products. Large barriers remain in realizing a cost-competitive process, for example, developing an optimal microbial cell factory. Here, we summarize the many tools and methods that have been developed in the metabolic engineering of isoprenoid production, with the advent of systems biology and synthetic biology, and discuss how these technologies advance to accelerate the design–build–test engineering cycle to obtain optimum microbial systems. It is anticipated that innovative combinations of new and existing technologies will continue to emerge, which will enable further development of microbial cell factories for commercial isoprenoid production.
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| 3. |
- Concaro, Sebastian, et al.
(författare)
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Bioreactors for Tissue Engineering of Cartilage
- 2009
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Ingår i: Advances in Biochemical Engineering/Biotechnology. - 0724-6145 .- 1616-8542. - 9783540693574 ; 112, s. 125-143
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- The cartilage regenerative medicine field has evolved during the last decades. The first-generation technology, autologous chondrocyte transplantation (ACT) involved the transplantation of in vitro expanded chondrocytes to cartilage defects. The second generation involves the seeding of chondrocytes in a three-dimensional scaffold. The technique has several potential advantages such as the ability of arthroscopic implantation, in vitro pre-differentiation of cells and implant stability among others (Brittberg M, Lindahl A, Nilsson A, Ohlsson C, Isaksson O, Peterson L, N Engl J Med 331(14):889-895, 1994; Henderson I, Francisco R, Oakes B, Cameron J, Knee 12(3):209-216, 2005; Peterson L, Minas T, Brittberg M, Nilsson A, Sjogren-Jansson E, Lindahl A, Clin Orthop (374):212-234, 2000; Nagel-Heyer S, Goepfert C, Feyerabend F, Petersen JP, Adamietz P, Meenen NM, et al. Bioprocess Biosyst Eng 27(4):273-280, 2005; Portner R, Nagel-Heyer S, Goepfert C, Adamietz P, Meenen NM, J Biosci Bioeng 100(3):235-245, 2005; Nagel-Heyer S, Goepfert C, Adamietz P, Meenen NM, Portner R, J Biotechnol 121(4):486-497, 2006; Heyland J, Wiegandt K, Goepfert C, Nagel-Heyer S, Ilinich E, Schumacher U, et al. Biotechnol Lett 28(20):1641-1648, 2006). The nutritional requirements of cells that are synthesizing extra-cellular matrix increase along the differentiation process. The mass transfer must be increased according to the tissue properties. Bioreactors represent an attractive tool to accelerate the biochemical and mechanical properties of the engineered tissues providing adequate mass transfer and physical stimuli. Different reactor systems have been [5] developed during the last decades based on different physical stimulation concepts. Static and dynamic compression, confined and nonconfined compression-based reactors have been described in this review. Perfusion systems represent an attractive way of culturing constructs under dynamic conditions. Several groups showed increased matrix production using confined and unconfined systems. Development of automatic culture systems and noninvasive monitoring of matrix production will take place during the next few years in order to improve the cost affectivity of tissue-engineered products. © 2009 Springer.
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| 4. |
- Dainiak, Maria, et al.
(författare)
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Chromatography of living cells using supermacroporous hydrogels, cryogels
- 2007
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Ingår i: Advances in Biochemical Engineering, Biotechnology. - Berlin, Heidelberg : Springer Berlin Heidelberg. - 0724-6145. ; 106, s. 101-127
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Tidskriftsartikel (refereegranskat)abstract
- The preparative cell separation is an intrinsic requirement of various diagnostic, biotechnological and biomedical applications. Affinity chromatography is a promising technique for cell separation and is based on the interaction between a cell surface receptor and an immobilised ligand. Most of the currently available matrices have pore size smaller than the size of the cells and are not suitable for cell chromatography due to column clogging. Another problem encountered in chromatographic separation of cells is a difficulty to elute bound cells from affinity surfaces. Application of novel adsorbents, supermacroporous monolithic cryogels, allows overcoming these problems. Cryogels are characterised by highly interconnected large (10-100 mu m) pores, sponge-like morphology and high elasticity. They are easily derivatised with any ligand of choice. Convective migration can be used to transport the cells through the matrix. Target cells bind to affinity ligands, while other cells pass through the cryogel column non-retained and are removed during a washing step. Because of the spongy and elastic nature of the cryogel matrices, the cells are efficiently desorbed by mechanical compression of cryogels, which provides high cell viability and yields. The release of affinity bound cells by mechanical compression of a cryogel monolithic adsorbent is a unique and efficient way of cell detachment. This detachment strategy and the continuous macroporous structure make cryogels very attractive for application in cell separation chromatography.
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| 5. |
- Dainiak, Maria, et al.
(författare)
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Methods in cell separations
- 2007
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Ingår i: Advances in Biochemical Engineering, Biotechnology. - Berlin, Heidelberg : Springer Berlin Heidelberg. - 0724-6145. ; 106, s. 1-18
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Tidskriftsartikel (refereegranskat)abstract
- Research in the field of cell biology and biomedicine relies on technologies that fractionate cell populations and isolate rare cell types to high purity. A brief overview of methods and commercially available products currently used in cell separations is presented. Cell fractionation by size and density and highly selective affinity-based technologies such as affinity chromatography, fluorescence-activated cell sorting (FACS) and magnetic cell sorting are discussed in terms of throughput, yield, and purity.
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| 6. |
- Danielsson, Bengt
(författare)
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Artificial receptors
- 2008
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Ingår i: Biosensing for the 21st Century (Advances in Biochemical Engineering/Biotechnology). - Berlin, Heidelberg : Springer Berlin Heidelberg. - 0724-6145. - 9783540752004 ; 109, s. 97-122
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Herein I will provide a brief overview of artificial receptors with emphasis on molecularly imprinted polymers (MIPs) and their applications. Alternative techniques to produce artificial receptors such as in silico designed and modelled polymers as well as different receptors designed using libraries of more or less natural composition will also be mentioned. Examples of these include aptamers and bio-nanocomposites. The physical presentation of the receptors is important and may depend on the application. Block polymerization of MIPs and grinding to particles of suitable size used to be the preferred technique, but today beaded materials can be produced in sizes down to nanobeads and also nanofibers can be used to increase available surface area and thereby capacity. For sensor applications it may be attractive to include the artificial receptors in surface coatings or in membrane structures. Different composite designs can be used to provide additional desirable properties. MIPs and other artificial receptors are gaining rapidly increasing attention in very shifting application areas and an attempt to provide a systematic account for current applications has been made with examples from separation, solid-phase extraction, analysis, carbohydrate specific experiments, and MIPs-directed synthesis.
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| 7. |
- Fernandes, Rita Lencastre, et al.
(författare)
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Applying Mechanistic Models in Bioprocess Development
- 2013
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Ingår i: Advances in Biochemical Engineering, Biotechnology. - Berlin, Heidelberg : Springer Berlin Heidelberg. - 0724-6145. ; 132, s. 137-166
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Tidskriftsartikel (refereegranskat)abstract
- The available knowledge on the mechanisms of a bioprocess system is central to process analytical technology. In this respect, mechanistic modeling has gained renewed attention, since a mechanistic model can provide an excellent summary of available process knowledge. Such a model therefore incorporates process-relevant input (critical process variables)-output (product concentration and product quality attributes) relations. The model therefore has great value in planning experiments, or in determining which critical process variables need to be monitored and controlled tightly. Mechanistic models should be combined with proper model analysis tools, such as uncertainty and sensitivity analysis. When assuming distributed inputs, the resulting uncertainty in the model outputs can be decomposed using sensitivity analysis to determine which input parameters are responsible for the major part of the output uncertainty. Such information can be used as guidance for experimental work; i.e., only parameters with a significant influence on model outputs need to be determined experimentally. The use of mechanistic models and model analysis tools is demonstrated in this chapter. As a practical case study, experimental data from Saccharomyces cerevisiae fermentations are used. The data are described with the well-known model of Sonnleitner and Kappeli (Biotechnol Bioeng 28: 927-937, 1986) and the model is analyzed further. The methods used are generic, and can be transferred easily to other, more complex case studies as well.
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| 8. |
- Galbe, Mats, et al.
(författare)
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Pretreatment of Lignocellulosic Materials for Efficient Bioethanol Production
- 2007
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Ingår i: Advances in Biochemical Engineering/Biotechnology. - Berlin, Heidelberg : Springer Berlin Heidelberg. - 0724-6145. - 9783540736509 ; 108, s. 41-65
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Bokkapitel (refereegranskat)abstract
- Second-generation bioethanol produced from various lignocellulosic materials, such as wood, agricultural or forest residues, has the potential to be a valuable substitute for, or a complement to, gasoline. One of the crucial steps in the ethanol production is the hydrolysis of the hemicellulose and cellulose to monomer sugars. The most promising method for hydrolysis of cellulose to glucose is by use of enzymes, i.e. cellulases. However, in order to make the raw material accessible to the enzymes some kind of pretreatment is necessary. During the last few years a large number of pretreatment methods have been developed, comprising methods working at low pH, i.e. acid based, medium pH (without addition of catalysts), and high pH, i.e. with a base as catalyst. Many methods have been shown to result in high sugar yields, above 90% of theoretical for agricultural residues, especially for corn stover. For more recalcitrant materials, e.g. softwood, acid hydrolysis and steam pretreatment with acid catalyst seem to be the methods that can be used to obtain high sugar and ethanol yields. However, for more accurate comparison of different pretreatment methods it is necessary to improve the assessment methods under real process conditions. The whole process must be considered when a performance evaluation is to be made, as the various pretreatment methods give different types of materials. (Hemicellulose sugars can be obtained either in the liquid as monomer or oligomer sugars, or in the solid material to various extents; lignin can be either in the liquid or remain in the solid part; the composition and amount/concentration of possible inhibitory compounds also vary.) This will affect how the enzymatic hydrolysis should be performed(e.g. with or without hemicellulases), how the lignin is recovered and also the use of the lignin co-product.
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| 9. |
- Galbe, Mats, et al.
(författare)
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Process Engineering Economics of Bioethanol Production
- 2007
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Ingår i: Advances in Biochemical Engineering/Biotechnology. - Berlin, Heidelberg : Springer Berlin Heidelberg. - 0724-6145. - 9783540736509 ; 108, s. 303-327
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Bokkapitel (refereegranskat)abstract
- This work presents a review of studies on the process economics of ethanol production from lignocellulosic materials published since 1996. Our objective was to identify the most costly process steps and the impact of various parameters on the fi- nal production cost, e.g. plant capacity, raw material cost, and overall product yield, as well as process configuration. The variation in estimated ethanol production cost is considerable, ranging from about 0.13 to 0.81 US$ per liter ethanol. This can be explained to a large extent by actual process differences and variations in the assumptions underlying the techno-economic evaluations. The most important parameters for the economic outcome are the feedstock cost, which varied between 30 and 90US$ per metric ton in the papers studied, and the plant capacity, which influences the capital cost. To reduce the ethanol production cost it is necessary to reach high ethanol yields, as well as a high ethanol concentration during fermentation, to be able to decrease the energy required for distillation and other downstream process steps. Improved pretreatment methods, enhanced enzymatic hydrolysis with cheaper and more effective enzymes, as well as improved fermentation systems present major research challenges if we are to make lignocellulose-based ethanol production competitive with sugar- and starch-based ethanol. Process integration, either internally or externally with other types of plants, e.g. heat and power plants, also offers a way of reducing the final ethanol production cost.
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| 10. |
- Hahn-Hägerdal, Bärbel, et al.
(författare)
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Metabolic engineering for pentose utilization in Saccharomyces cerevisiae
- 2007
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Ingår i: Advances in Biochemical Engineering/Biotechnology. - Berlin, Heidelberg : Springer Berlin Heidelberg. - 0724-6145. - 9783540736509 ; 108, s. 147-177
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- The introduction of pentose utilization pathways in baker's yeast Saccharomyces cerevisiae is summarized together with metabolic engineering strategies to improve ethanolic pentose fermentation. Bacterial and fungal xylose and arabinose pathways have been expressed in S. cerevisiae but do not generally convey significant ethanolic fermentation traits to this yeast. A large number of rational metabolic engineering strategies directed among others toward sugar transport, initial pentose conversion, the pentose phosphate pathway, and the cellular redox metabolism have been exploited. The directed metabolic engineering approach has often been combined with random approaches including adaptation, mutagenesis, and hybridization. The knowledge gained about pentose fermentation in S. cerevisiae is primarily limited to genetically and physiologically well-characterized laboratory strains. The translation of this knowledge to strains performing in an industrial context is discussed.
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