The Experts below are selected from a list of 20688 Experts worldwide ranked by ideXlab platform
Susan C Roberts - One of the best experts on this subject based on the ideXlab platform.
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The Interface amongst Conserved and Specialized Pathways in Non-Paclitaxel and Paclitaxel Accumulating Taxus Cultures
'MDPI AG', 2021Co-Authors: Michelle C. Mckee, Sarah A Wilson, Susan C RobertsAbstract:Plant Cell Cultures derived from Taxus are used to produce valuable metabolites like paclitaxel, a chemotherapeutic drug. Methyl jasmonate elicitation enhances paclitaxel accumulation, but also inhibits Culture growth and increases phenylpropanoid biosynthesis, two side effects that detract from taxane accumulation. To understand the connection between all of these processes, a systems approach is applied to investigate Cell-wide metabolism in Taxus. Non-paclitaxel and paclitaxel accumulating Cultures were elicited over single and multi-generational periods, and subsequent changes in conserved and specialized metabolism were quantified. Methyl jasmonate typically resulted in decreased growth and increased metabolite content in paclitaxel accumulating Cultures. Conversely, elicitation typically resulted in either no change or decrease in accumulation of metabolites in the non-paclitaxel accumulating Cultures. In both sets of Cultures, variability was seen in the response to methyl jasmonate across generations of Cell growth. Consolidation of these data determined that paclitaxel accumulation and basal levels of phenolic and flavonoid compounds are indirectly correlated with aggregate size. These approaches assess alternative metabolic pathways that are linked to paclitaxel biosynthesis and provide a comprehensive strategy to both understand the relationship between conserved and specialized metabolism in Plants and in the design of strategies to increase natural product yields in Plant Cell Culture
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recent advances towards development and commercialization of Plant Cell Culture processes for the synthesis of biomolecules
Plant Biotechnology Journal, 2012Co-Authors: Sarah A Wilson, Susan C RobertsAbstract:Plant Cell Culture systems were initially explored for use in commercial synthesis of several high-value secondary metabolites, allowing for sustainable production that was not limited by the low yields associated with natural harvest or the high cost associated with complex chemical synthesis. Although there have been some commercial successes, most notably paclitaxel production from Taxus sp., process limitations exist with regards to low product yields and inherent production variability. A variety of strategies are being developed to overcome these limitations including elicitation, in situ product removal and metabolic engineering with single genes and transcription factors. Recently, the Plant Cell Culture production platform has been extended to pharmaceutically active heterologous proteins. Plant systems are beneficial because they are able to produce complex proteins that are properly glycosylated, folded and assembled without the risk of contamination by toxins that are associated with mammalian or microbial production systems. Additionally, Plant Cell Culture isolates transgenic material from the environment, allows for more controllable conditions over field-grown crops and promotes secretion of proteins to the medium, reducing downstream purification costs. Despite these benefits, the increase in cost of heterologous protein synthesis in Plant Cell Culture as opposed to field-grown crops is significant and therefore processes must be optimized with regard to maximizing secretion and enhancing protein stability in the Cell Culture media. This review discusses recent advancements in Plant Cell Culture processing technology, focusing on progress towards overcoming the problems associated with commercialization of these production systems and highlighting recent commercial successes.
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Characterization of aggregate size in Taxus suspension Cell Culture
Plant Cell Reports, 2010Co-Authors: Martin E. Kolewe, Michael A. Henson, Susan C RobertsAbstract:Plant Cells grow as aggregates in suspension Culture, but little is known about the dynamics of aggregation, and no routine methodology exists to measure aggregate size. In this study, we evaluate several different methods to characterize aggregate size in Taxus suspension Cultures, in which aggregate diameters range from 50 to 2,000 μm, including filtration and image analysis, and develop a novel method using a specially equipped Coulter counter system. We demonstrate the suitability of this technology to measure Plant Cell Culture aggregates, and show that it can be reliably used to measure total biomass accumulation compared to standard methods such as dry weight. Furthermore, we demonstrate that all three methods can be used to measure an aggregate size distribution, but that the Coulter counter is more reliable and much faster, and also provides far better resolution. While absolute measurements of aggregate size differ based on the three evaluation techniques, we show that linear correlations are sufficient to account for these differences ( R ^2 > 0.99). We then demonstrate the utility of the novel Coulter counter methodology by monitoring the dynamics of a batch process and find that the mean aggregate size increases by 55% during the exponential growth phase, but decreases during stationary phase. The results indicate that the Coulter counter method can be routinely used for advanced process characterization, particularly to study the relationship between aggregate size and secondary metabolite production, as well as a source of reliable experimental data for modeling aggregation dynamics in Plant Cell Culture.
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pharmaceutically active natural product synthesis and supply via Plant Cell Culture technology
Molecular Pharmaceutics, 2008Co-Authors: Martin E. Kolewe, Vishal Gaurav, Susan C RobertsAbstract:The chemical diversity of Plant-derived natural products allows them to function in a multitude of ways including flavor enhancers, agricultural chemicals, and importantly, human medicinals. Supply of pharmaceutically active natural products is often a challenge due to the slow growing nature of some species, low yields found in nature, and unpredictable variability in accumulation. Several production options are available including natural harvestation, total chemical synthesis, semisynthesis from isolated precursors, and expression of Plant pathways in microbial systems. However, for some medicinal natural products, such as the anticancer agent paclitaxel, where low yields in nature, chemical complexity and lack of knowledge of the complete biosynthetic pathway, preclude many of these options, Plant Cell Culture technology is an attractive alternative for supply. Plant Cell suspension Cultures are amenable to scale-up, environmental optimization, and metabolic engineering. This review focuses on some of...
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production and engineering of terpenoids in Plant Cell Culture
Nature Chemical Biology, 2007Co-Authors: Susan C RobertsAbstract:Terpenoids are a diverse class of natural products that have many functions in the Plant kingdom and in human health and nutrition. Their chemical diversity has led to the discovery of over 40,000 different structures, with several classes serving as important pharmaceutical agents, including the anticancer agents paclitaxel (Taxol) and terpenoid-derived indole alkaloids. Many terpenoid compounds are found in low yield from natural sources, so Plant Cell Cultures have been investigated as an alternate production strategy. Metabolic engineering of whole Plants and Plant Cell Cultures is an effective tool to both increase terpenoid yield and alter terpenoid distribution for desired properties such as enhanced flavor, fragrance or color. Recent advances in defining terpenoid metabolic pathways, particularly in secondary metabolism, enhanced knowledge concerning regulation of terpenoid accumulation, and application of emerging Plant systems biology approaches, have enabled metabolic engineering of terpenoid production. This paper reviews the current state of knowledge of terpenoid metabolism, with a special focus on production of important pharmaceutically active secondary metabolic terpenoids in Plant Cell Cultures. Strategies for defining pathways and uncovering rate-influencing steps in global metabolism, and applying this information for successful terpenoid metabolic engineering, are emphasized.
Michael Wink - One of the best experts on this subject based on the ideXlab platform.
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production and secretion of recombinant thaumatin in tobacco hairy root Cultures
Biotechnology Journal, 2012Co-Authors: Ngoc Bich Pham, Holger Schafer, Michael WinkAbstract:Production of recombinant proteins in Plant Cell or organ Cultures and their secretion into the Plant Cell Culture medium simplify the purification procedure and increase protein yield. In this study, the sweet-tasting protein thaumatin I was expressed and successfully secreted from tobacco hairy root Cultures. The presence of an ER signal peptide appears to be crucial for the secretion of thaumatin: without an ER signal peptide, no thaumatin was detectable in the spent medium, whereas inclusion of the ER signal peptide calreticulin fused to the N terminus of thaumatin led to the secretion of thaumatin into the spent medium of hairy root Cultures at concentrations of up to 0.21 mg/L. ExtraCellular thaumatin levels reached a maximum after 30 days (stationary phase) and the subsequent decline was linked to the rapid increase of proteases in the medium. Significant amounts of thaumatin were trapped in the apoplastic space of the root Cells. The addition of polyvinylpyrrolidone and sodium chloride into the Culture medium led to an increase of extraCellular thaumatin amounts up to 1.4 and 2.63 mg/L, respectively. Thaumatin production compares well with yields from other transgenic Plants, so that tobacco hairy roots can be considered an alternative production platform of thaumatin. See accompanying commentary by Eva Stoger DOI: 10.1002/biot.201100472
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production and secretion of recombinant thaumatin in tobacco hairy root Cultures
Biotechnology Journal, 2012Co-Authors: Ngoc Bich Pham, Holger Schafer, Michael WinkAbstract:Production of recombinant proteins in Plant Cell or organ Cultures and their secretion into the Plant Cell Culture medium simplify the purification procedure and increase protein yield. In this study, the sweet-tasting protein thaumatin I was expressed and successfully secreted from tobacco hairy root Cultures. The presence of an ER signal peptide appears to be crucial for the secretion of thaumatin: without an ER signal peptide, no thaumatin was detectable in the spent medium, whereas inclusion of the ER signal peptide calreticulin fused to the N terminus of thaumatin led to the secretion of thaumatin into the spent medium of hairy root Cultures at concentrations of up to 0.21 mg/L. ExtraCellular thaumatin levels reached a maximum after 30 days (stationary phase) and the subsequent decline was linked to the rapid increase of proteases in the medium. Significant amounts of thaumatin were trapped in the apoplastic space of the root Cells. The addition of polyvinylpyrrolidone and sodium chloride into the Culture medium led to an increase of extraCellular thaumatin amounts up to 1.4 and 2.63 mg/L, respectively. Thaumatin production compares well with yields from other transgenic Plants, so that tobacco hairy roots can be considered an alternative production platform of thaumatin. See accompanying commentary by Eva Stoger DOI: 10.1002/biot.201100472
Laurence Fazan - One of the best experts on this subject based on the ideXlab platform.
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overcoming sexual sterility in conservation of endangered species the prominent role of biotechnology in the multiplication of zelkova sicula ulmaceae a relict tree at the brink of extinction
Plant Cell Tissue and Organ Culture, 2019Co-Authors: Angela Carra, Caterina Catalano, Ornella Badalamenti, Francesco Carimi, S Pasta, Antonio Motisi, Loredana Abbate, Francesca La Bella, Laurence FazanAbstract:Biotechnology provides valuable tools to support conservation of Plant species, especially in case of threatened taxa or when dealing with seed unavailability, low viability or sterility. However, Plant Cell Culture methods have often to face problems associated with tissue recalcitrance to in vitro systems. Recalcitrance can be related to a variety of triggering factors, involving many efforts and manipulations within one or more of the micropropagation stages before obtaining successful results. An in vitro propagation protocol was developed for Zelkova sicula, a very rare and endangered relict tree, endemic to Sicily (Southern Italy). The species revealed extremely recalcitrant to in vitro Culture approaches, but after many trials throughout a number of years an effective micropropagation protocol was completed. The rooting rate was about 84% of the treated exPlants, 8% of which were successfully acclimatized outdoor and reintroduced in the wild within a comprehensive conservation project. The technique allowed to overcome the problems of sexual sterility of this species, hence contributing concretely to contrast the problems connected with its conservation. However, additional efforts need to be carried out in order to refine the acclimatization step and further improve the whole process effectiveness. A micropropagation protocol was developed for the rare and endangered tree species Zelkova sicula. The in vitro procedure allowed to overcome seed sterility providing a Plant stock successfully reintroduced in the wild.
S Pasta - One of the best experts on this subject based on the ideXlab platform.
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overcoming sexual sterility in conservation of endangered species the prominent role of biotechnology in the multiplication of zelkova sicula ulmaceae a relict tree at the brink of extinction
Plant Cell Tissue and Organ Culture, 2019Co-Authors: Angela Carra, Caterina Catalano, Ornella Badalamenti, Francesco Carimi, S Pasta, Antonio Motisi, Loredana Abbate, Francesca La Bella, Laurence FazanAbstract:Biotechnology provides valuable tools to support conservation of Plant species, especially in case of threatened taxa or when dealing with seed unavailability, low viability or sterility. However, Plant Cell Culture methods have often to face problems associated with tissue recalcitrance to in vitro systems. Recalcitrance can be related to a variety of triggering factors, involving many efforts and manipulations within one or more of the micropropagation stages before obtaining successful results. An in vitro propagation protocol was developed for Zelkova sicula, a very rare and endangered relict tree, endemic to Sicily (Southern Italy). The species revealed extremely recalcitrant to in vitro Culture approaches, but after many trials throughout a number of years an effective micropropagation protocol was completed. The rooting rate was about 84% of the treated exPlants, 8% of which were successfully acclimatized outdoor and reintroduced in the wild within a comprehensive conservation project. The technique allowed to overcome the problems of sexual sterility of this species, hence contributing concretely to contrast the problems connected with its conservation. However, additional efforts need to be carried out in order to refine the acclimatization step and further improve the whole process effectiveness. A micropropagation protocol was developed for the rare and endangered tree species Zelkova sicula. The in vitro procedure allowed to overcome seed sterility providing a Plant stock successfully reintroduced in the wild.
Fernando Orozcosanchez - One of the best experts on this subject based on the ideXlab platform.
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bioprocess Plant design and economic analysis of an environmentally friendly insect controller agent produced with azadirachta indica Cell Culture
Biochemical Engineering Journal, 2020Co-Authors: Santiago Benavideslopez, Juan Oviedoramirez, Juandavid Lopeztaborda, Anny Martinezmira, Andres Vasquezrivera, Rodrigo Hoyossanchez, Fernando OrozcosanchezAbstract:Abstract Chemical pesticides cause serious problems to the environment, as well as human and animal health. A conceptual design and economic analysis was carried out for a hypothetical factory in order to produce an environmentally friendly insect controller agent from Azadirachta indica Cell Culture. The proposed factory is composed of a series of bioreactors that can produce 60.0 kg of active compound/batch. This designed Plant had a capacity of 136 batches/year, which represents 40,800 kg of bioinsecticide, and it was located in Medellin (Colombia) with a total building cost of 12.2 million USD. Three bioinsecticide formulations, two equipment costs and variation in product/substrate yields were analyzed. To achieve profitability in the project, the minimum selling price of the formulated products was calculated between 76.9–330.0 USD/kg (Net Present Value > 0). This is the first report of a bioprocess factory design and economic analysis for an insect controller agent using Plant Cell Culture.
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rheology and mixing analysis of Plant Cell Cultures azadirachta indica borojoa patinoi and thevetia peruviana in shake flasks
Biochemical Engineering Journal, 2016Co-Authors: Astrid Catalina Alvarezyela, Laura Natalia Chiquizamontano, Rodrigo Hoyos, Fernando OrozcosanchezAbstract:Abstract Plant Cell Culture is a useful technology for the production of secondary metabolites with commercial and pharmaceutical value. The rheology, morphology or aggregation of Cell suspension have different applications in flow systems, bioreactor design and unit operations. This suggests solutions to mixing, mass transfer, hydrodynamic stress and Cell growth problems. In this study, some morphological aspects associated with elliptical form factor and the tendency to form Cell aggregates of Azadirachta indica , Borojoa patinoi and Thevetia peruviana Cell Cultures were evaluated in shake flasks. The rheological behavior through rheograms for Cell concentrations of 0, 4, 8 and 12 g DW l ⿿1 was also evaluated. From this data, properties and parameters like apparent viscosity, Reynolds number, phase state and volumetric power were calculated for shake flasks of 250 and 500 ml. The results showed a dilatant behavior of the Culture medium and pseudo-plastic behavior of Cell Cultures. This last behavior increases with Cell concentration and size of the Cell aggregates. Rheograms for all Cell concentrations of A. indica , were significantly different from the other two species. Culture conditions like shaker orbit diameters and flask volumes were recommended in order to favor an adequate Cell growth and mass transfer in Plant Cell Cultures.