REFERENCES

1. Study of the effect of sugar starvation at various O2 conditions on isolated cells from leafy vegetables on Lambda Minifor. 2017:

Abstract: Sugar starvation is a common phenomenon occurring in most leafy vegetables after harvest and storage. Additionally, leafy vegetables are subjected to low O2 stress when stored in modified atmosphere conditions. In this study, the metabolism of isolated lamb’s lettuce cells was studied upon sugar starvation under O2 stress conditions, using 13C labelled glucose. Fast depletions of the soluble sugars were observed, being more pronounced under aerobic conditions than under low O2 stress conditions. Sugar starvation under aerobic conditions resulted in increased levels and decreased 13C label incorporation of TCA cycle intermediates and amino and fatty acids originating from glycolytic and TCA cycle pathways, compared to starving cells incubated under low O2stress. On incubation under low O2 stress a switch in metabolism from aerobic to fermentation metabolism was observed. Under low O2 stress conditions, increased levels and 13C label incorporated in hexose phosphates, pyruvate, lactate, GABA, alanine, together with increased levels of acetaldehyde, ethanol and ethyl acetate was observed indicating fermentative metabolism was triggered.

2. Robust cellulosic ethanol production from sugarcane bagasse with Saccharomyces cerevisiae ATCC 20602 in LAMBDA MINIFOR laboratory bioreactor under aerobic and anaerobic conditions with controlled redox potential measurement: 2016.

Abstract: The present study deals with the production of cellulosic ethanol from bagasse using the synthesized TiO2 coupled nanocellulose (NC-TiO2) as catalyst. Aspergillus nidulans AJSU04 cellulase was used for the hydrolysis of bagasse. NC-TiO2 at various concentrations was added to bagasse in order to enhance the yield of reducing sugars. Complex interaction between cellulase, bagasse, NC-TiO2 and the reaction environment is thoroughly studied. A mathematical model was developed to describe the hydrolysis reaction. Ethanol production from enzymatically hydrolyzed sugarcane bagasse catalyzed with NC-TiO2 was carried out using Saccharomyces cerevisiae ATCC 20602. The glucose release rates and ethanol concentrations were determined. Ethanol produced was found to be strongly dependent on pretreatment given, hydrolysis and fermentation conditions. The study confirmed the promising accessibility of NC-TiO2, for enhanced glucose production rates and improved ethanol yield.

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3. S. pyogenes Cas9 protein expressed using a 3L computer-controlled MINIFOR bioreactor in batch medium followed by exponential feeding: 2015.

Homology-directed repair in rodent zygotes using Cas9 and TALEN engineered proteins.Ménoret, Séverine, Anne De Cian, Laurent Tesson, Séverine Remy, Claire Usal, Jean-Baptiste Boulé, Charlotte Boix et al.  Scientific reports5 (2015). 2015; 7 Oct 2015. Nature ublishing Group. INSERM UMR 1064-ITUN; CNRS UMS3556 Nantes; CNRS UMR7196; Sorbonne Universities; University Pierre & Marie Curie; France. 

 

Abstract: The generation of genetically-modified organisms has been revolutionized by the development of new genome editing technologies based on the use of gene-specific nucleases, such as meganucleases, ZFNs, TALENs and CRISPRs-Cas9 systems. The most rapid and cost-effective way to generate genetically-modified animals is by microinjection of the nucleic acids encoding gene-specific nucleases into zygotes. However, the efficiency of the procedure can still be improved. In this work we aim to increase the efficiency of CRISPRs-Cas9 and TALENs homology-directed repair by using TALENs and Cas9 proteins, instead of mRNA, microinjected into rat and mouse zygotes along with long or short donor DNAs. We observed that Cas9 protein was more efficient at homology-directed repair than mRNA, while TALEN protein was less efficient than mRNA at inducing homology-directed repair. Our results indicate that the use of Cas9 protein could represent a simple and practical methodological alternative to Cas9 mRNA in the generation of genetically-modified rats and mice as well as probably some other mammals.

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4. Fermentation of engineered microorganism in laboratory scale bioreactor MINIFOR for efficient conversion of lactose-to-ethanol: 2015.

"Methods for genetic optimization of biocatalysts for biofuel production from dairy waste through synthetic biology."Pasotti, L., S. Zucca, M. Casanova, N. Politi, I. Massaiu, G. Mazzini, G. Micoli, C. Calvio, M. G. Cusella De Angelis, and P. Magni. In Engineering in Medicine and Biology Society (EMBC), 2015 37th Annual International Conference of the IEEE, pp. 953-956. IEEE, 2015. Department of Electrical, Computer & Biomedical Engineering and Interdepartmental Research Centre for Tissue Engineering, University of Pavia, Italy. Keywords: lactose-to-ethanol conversion; microorganism optimization; synthetic biology; whey protein; permeate; pollutant waste disposal; genetic optimization; green energy production; biofuel production; cheese production process; dairy waste; biocatalyst

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Abstract: Whey is an abundant by-product of cheese production process and it is considered a special waste due to its high nutritional load and hypertrophic potential. Technologies for whey valorization are available. They can convert such waste into high-value products, like whey proteins. However, the remaining liquid (called permeate) is still considered as a polluting waste due to its high lactose concentration. The alcoholic fermentation of lactose into ethanol will simultaneously achieve two important goals: safe disposal of a pollutant waste and green energy production. This methodology paper illustrates the workflow carried out to design and realize an optimized microorganism that can efficiently perform the lactose-to-ethanol conversion, engineered via synthetic biology experimental and computational approaches.

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5. Six-species flow cell biofilm model was developed by culturing bacteria in LAMBDA MINIFOR Bioreactor to evaluate the biofilm development under flow and shear conditions: 2015.

The use of in vitro model systems to study dental biofilms associated with caries: a short review. Salli, Krista M., and Arthur C. Ouwehand.Journal of oral Microbiology 7 (2015). J Oral Microbiol. 2015; 7: 10.3402/jom.v7.26149. DuPont Nutrition and Health, Kantvik Active Nutrition, Finland. Keywords: dental caries, batch culture, continuous culture, artificial mouth, flow cell, microcosm 

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Abstract: A dental biofilm forms a distinct environment where microorganisms live in a matrix of extracellular polysaccharides. The biofilm favors certain bacteria and creates a habitat that functions differently compared to planktonic bacteria. Reproducible model systems which help to address various questions related to biofilm formation, the process of caries development, and its prevention are needed and are continuously developed. Recent research using both batch culture, continuous culture and flow cells in caries biofilm formation is presented. The development of new techniques and equipment has led to a deeper understanding of how caries biofilms function. Biofilm models have also been used in the development of materials inhibiting secondary caries. This short review summarizes available models to study these questions.

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6. Quantification of ribosomal proteins (RPs) from Yeast cells cultured in MINIFOR and mouse embryonic stem cells (ESC) to study the core RPs stoichiometry: 2015.

Differential stoichiometry among core ribosomal proteins, arXiv:1406.0399 Nikolai Slavov, Stefan Semrau, Edoardo Airoldi, Bogdan Budnik, Alexander van Oudenaarden, , Jun 2015. Cell Reports 13 , 865–873 November 3, 2015. Harvard University, USA; Broad Institute of MIT and Harvard, USA and Hubrecht Institute, Netherlands . Keywords: Budding Yeast cells, Embryonic stem cells (ESC), Ribosomal Protein, RP, ribosomes, mRNA, mass-spectrometry, posttranslational modification, PTM)

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Abstract: Understanding the regulation and structure of ribosomes is essential to understanding protein synthesis and its deregulation in disease. While ribosomes are believed to have a fixed stoichiometry among their core ribosomal proteins (RPs), some experiments suggest a more variable composition. Testing such variability requires direct and precise quantification of RPs. We used mass-spectrometry to directly quantify RPs across monosomes and polysomes of mouse embryonic stem cells (ESC) and budding yeast. Our data show that the stoichiometry among core RPs in wild-type yeast cells and ESC depends both on the growth conditions and on the number of ribosomes bound per mRNA. Furthermore, we find that the fitness of cells with a deleted RP-gene is inversely proportional to the enrichment of the corresponding RP in polysomes. Together, our findings support the existence of ribosomes with distinct protein composition and physiological function.

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7. Growing yeast cultures (DBY12007) in MINIFOR at steady state to study the aerobic glycolysis and energy flux: 2014.

Constant Growth Rate Can Be Supported by Decreasing Energy Flux and Increasing Aerobic Glycolysis. Nikolai Slavov, Bogdan A. Budnik, David Schwab, Edoardo M. Airoldi, and Alexander van Oudenaarden, Cell Reports 7, 705–714, May 8, 2014   Massachusetts Institute of Technology, USA; Harvard University, USA; Hubrecht Institute, Netherlands and Princeton University, USA. Keywords: Yeast, aerobic glycolysis, exponential growth, O2 consumption, CO2 production, amino acids, mRNAs, proteins, posttranslational modifications, stress sensitivity, respiratory quotient (RQ)

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Abstract: Fermenting glucose in the presence of enough oxygen to support respiration, known as aerobic glycolysis, is believed to maximize growth rate. We observed increasing aerobic glycolysis during exponential growth, suggesting additional physiological roles for aerobic glycolysis. We investigated such roles in yeast batch cultures by quantifying O2 consumption, CO2 production, amino acids, mRNAs, proteins, posttranslational modifications, and stress sensitivity in the course of nine doublings at constant rate. During this course, the cells support a constant biomass-production rate with decreasing rates of respiration and ATP production but also decrease their stress resistance. As the respiration rate decreases, so do the levels of enzymes catalyzing rate-determining reactions of the tricarboxylic-acid cycle (providing NADH for respiration) and of mitochondrial folate-mediated NADPH production (required for oxidative defense). The findings demonstrate that exponential growth can represent not a single metabolic/physiological state but a continuum of changing states and that aerobic glycolysis can reduce the energy demands associated with respiratory metabolism and stress survival.

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8. LAMBDA MINIFOR bioreactor to grow the oral bacteria (Streptococcus oralis, Actinomyces naeslundii, Veillonella parvula, Fusobacterium nucleatum, Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis) under planktonic conditions: 2014.

Abstract: Bacteria in the oral cavity grow in the form of biofilms; these structures are subject to constant saliva or gingival crevicular fluid flow conditions. The aims of this study were: (i) to develop and to characterize an in-vitro biofilm model with oral bacteria growing under flow and shear conditions; and (ii) to demonstrate the usefulness of the model for evaluating the activity of three antiplaque agents.We used a bioreactor to grow the oral bacteria Streptococcus oralis, Actinomyces naeslundii, Veillonella parvula, Fusobacterium nucleatum, Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis under planktonic conditions. Biofilms were established using a modified Robbins device on hydroxyapatite (HAP) discs. Three- to 7-d-old biofilms were analysed using culture methods, scanning electron microscopy, Live/Dead staining and fluorescence in-situ hybridization (confocal laser scanning microscopy). Finally, we assessed the antimicrobial activity of three mouthrinses [0.12% chlorhexidine (CHX), 0.12% chlorhexidine and sodium fluoride (CHX+NaF) and 0.12% chlorhexidine and 0.05% cetylpyridinium chloride (CHX+CPC)] using a planktonic test (short interval–killing test) and in our 4-d biofilm model. The viable cell counts showed that each species was consistently found in the biofilms throughout the study. The architecture and cell distribution were similar to those described for biofilms in situ, with the exception of a thin layer of living cells that was found close to the HAP. The effectiveness test of the mouthwashes demonstrated that cells in biofilms showed more tolerance compared with planktonic cells. Moreover, it was observed that in 4-d biofilm formed in vitro, CHX+CPC caused significantly higher mortality compared with CHX (p = 0.003) and CHX+NaF (p < 0.001). Our results suggest that we have a highly reproducible system for multispecies oral biofilm formation and that it is a useful tool for assessing antibacterial molecules before their clinical evaluation. It also has great potential to be used in basic research on supragingival and subgingival biofilms.

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9. Cultivation of microalgae (Chlorella vulgaris Beyerinck) in laboratory bioreactor MINIFOR: 2014.

Mikrovetikate Chlorella vulgaris kasvatamise eelkatsed bioreaktoris Lambda Minifor
Heitur, Heiko. "Mikrovetika Chlorella vulgaris Beyerincki kasvatamine CO2 sidumise eesmärgil." PhD diss., 2014. Estonian University of Life Sciences, Estonia. 

 

 

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10. Selective and non-selective batch fermentation of date extract using Saccharomyces cerevisiae (commercial strain used in bakeries (wild strain), glucose selective strains ATCC 36858 and ATCC 36859) studied in LAMBDA MINIFOR fermentor: 2014.

Selective fermentation of pitted dates by S. cerevisiae for the production of concentrated fructose syrups and ethanol,  Meilana Dharma Putra, Ahmed E. Abasaeed, Mohamed A. Zeinelabdeen, Mohamed H. Gaily, Ashraf K. Sulieman, Journal of Physics: Conference Series 495 (2014) 012034  Chemical Engineering Department, King Saud University, Saudi Arabia. Keywords: Selective, non-selective, fermentation, yeast, S. cerevisiae, fructose, ethanol, date, HPLC, kinetic profile, batch.

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Abstract: About half of worldwide production of dates is unconsumed. Dates contain over 75 % reduced sugars (mostly glucose and fructose with nearly equal amount). Compared to the commercial Saccharomyces cerevisiae wild strain, the strains ATCC 36858 and 36859 could produce high concentration fructose syrups. The fructose fractions obtained were 95.9 and 97.4% for ATCC 36858 and 86.5 and 91.4% for ATCC 36859 at 30 and 33°C, respectively. Fructose yields higher than 90% were obtained using ATCC 36858 compared to those obtained using ATCC 36859 which were 87.3 and 66.1% at 30 and 33°C, respectively. The ethanol yield using ATCC 36858 was higher than that using ATCC 36859 by 16 and 9% at 30 and 33°C, respectively. Through this finding, the production of fructose and ethanol from date extract is a promising process. Moreover, the fructose fractions obtained here (about 90%) are much higher than those obtained with the commercial process, i.e. 55 % fructose syrups.

11. Controlled growth of Staphylococcus aureus under various concentrations of BAC (benzalkonium chloride) in MINIFOR fermentor. 2013:

The Role of the qacA Gene in Mediating Resistance to Quaternary Ammonium Compounds. Dana Cervinkova, Vladimir Babak, Durdica Marosevic, Iva Kubikova, and Zoran Jaglic. Microbial Drug Resistance. June 2013, 19(3): 160-167.  Veterinary Research Institute, Brno, Czech Republic. Keywords: Staphylococcus aureus, benzalkonium chloride (BAC), exponential phase, expression, real-time PCR, culture, concentration

Reference MINIFOR usehttp://online.liebertpub.com/templates/jsp/_style2/_mal/images/docReqArticlePDF.jpg

Abstract: Conditions facilitating resistance to quaternary ammonium compounds (QACs) were investigated in Staphylococcus aureus SK982 exposed to benzalkonium chloride (BAC; a member of QACs) under various circumstances. S. aureus SK982 carrying the qacA gene encoding for resistance to QACs was grown in the presence of stable or gradually increasing concentrations of BAC, or it was exposed to this antiseptic in the exponential phase of growth. Bacteria cultivated in the highest BAC concentrations that did not retard their growth comparing to the untreated control were subjected to real-time quantitative polymerase chain reaction analysis for relative expression of the efflux genes qacA and norA. Under such conditions, S. aureus SK982 tolerated a relatively low stable concentration of BAC (1.22 mg/L) when compared with a gradually increasing antiseptic concentration (tolerance of 4.88 mg/L). However, in both cases, qacA expression was not significant. The culture exposed in the exponential phase of growth tolerated the highest concentration of BAC (9.76 mg/L) as also accompanied by significant overexpression of qacA. Expression of norA was relatively low regardless of the conditions tested. It seems that under the short-term conditions, the phase of bacterial growth is more important for the expression of BAC resistance than the capability to adapt to this antiseptic. This study provides a deeper insight into the relevance of the qac genes in conferring resistance to QACs.

12. Systems for High-Density Hybridoma Growth and High-yield mAb production in cell culture: Bench-top stirred tank bioreactors, 1-5 L (MINIFOR - LAMBDA Laboratory Instruments). 2013:

Abstract: Antibodies protect us from a wide range of infectious diseases and cancers and have become an indispensable tool in science—both for conventional immune response research as well as other areas related to protein identification analysis. This second edition of Making and Using Antibodies: A Practical Handbook provides clear guidance on all aspects of how to make and use antibodies for research along with their commercial and industrial applications... From the eradication of smallpox to combating cancer, antibodies present an attractive solution to a range of biomedical problems. They are relatively easy to make and use, have great flexibility in applications, and are cost effective for most labs. This volume will assist biomedical researchers and students and pave the way for future discovery of new methods for making and using antibodies for a host of applications.

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13. The metabolic stress response of tomato cell culture (Lycopersicum esculentum) to low oxygen studied using LAMBDA MINIFOR Bioreactor. 2013:

The metabolic response of cultured tomato cells to low oxygen stress.  Ampofo-Asiama, J., Baiye, V. M. M., Hertog, M. L. A. T. M., Waelkens, E., Geeraerd, A. H., Nicolai, B. M. (2013), Plant Biology. German Botanical Society and The Royal Botanical Society of the Netherlands. Keywords: 3C label; cell culture; low O2 stress; Lycopersicum esculentum; metabolome

Plant Biology

Abstract: The storage of fruits and vegetables under a controlled atmosphere can induce low oxygen stress, which can lead to post-harvest losses through the induction of disorders such as core breakdown and browning. To gain better understanding of the metabolic response of plant organs to low oxygen, cultured tomato cells (Lycopersicum esculentum) were used as a model system to study the metabolic stress response to low oxygen (0 and 1 kPa O2). By adding 13C labelled glucose, changes in the levels of polar metabolites and their 13C label accumulation were quantified. Low oxygen stress altered the metabolite profile of tomato cells, with the accumulation of the intermediates of glycolysis in addition to increases in lactate and sugar alcohols. 13C label data showed reduced label accumulation in almost all metabolites except lactate and some sugar alcohols. The results showed that low oxygen stress in tomato cell culture activated fermentative metabolism and sugar alcohol synthesis while inhibiting the activity of the TCA cycle and the biosynthesis of metabolites whose precursors are derived from central metabolism, including fluxes to most organic acids, amino acids and sugars.

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14. LAMBDA MINIFOR Bioreactor used for recombinant protein (Chemokines) expression in E. coli. 2013:

PhD Thesis. 2013. Birgit Kramp, "Establishing the interaction between the CC chemokine ligand 5 and the receptors CCR1 and CCR5
Fakultät für Mathematik, Informatik und Naturwissenschaften, RWTH Aachen, Belgium.

 

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15. Recombinant expression of the Met-CCL5, protease resistant CXCL12 (S4V) and F1-CX3CL1 in E. coli to study their role in Cardiovascular disease (CVD). 2013:

PhD Thesis. 2013. Projahn, D., Generation, function and therapeutic application of chemotactic cytokines in cardiovascular diseases
Institut für Molekulare Herz-Kreislaufforschung, Fakultät für Mathematik, Informatik und Naturwissenschaften, RWTH Aachen, Belgium.
Fakultät für Mathematik, Informatik und Naturwissenschaften, RWTH Aachen, Belgium.

 

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16. Expression of Caf1 protein using Escherichia coli strain to study mammalian cell adhesion, shape and number of focal adhesion. 2013:

PhD Thesis. 2013. Machado Roque, A. I., Protein scaffolds for cell culture, 2013 , Newcastle University

 

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17. MINIFOR Bioreactors for stem cells. 2012:

A non-rotational, computer-controlled suspension bioreactor for expansion of umbilical cord blood mononuclear cellsShayan, N., Ebrahimi, M., Beiki, B. and Janzamin, E. 2012. BIOTECHNOLOGY LETTERS. Department of Regenerative Medicine and Stem Cells and Developmental Biology, Cell Research Center, Royan Institute for Stem Cell Biology and Technology, Royan Cord Blood Bank, Tehran, Iran. Keywords: Static culture; Suspension bioreactor; Umbilical cord blood; Vertical mixing

Biotechnology LettersBiotechnology Letters

Abstract: The proliferation and differentiation characteristics of umbilical cord blood mononuclear cells were examined in a non-rotational suspension bioreactor with a fishtail mixer. The system consisted of a glass vessel, a mixer that moved vertically, a data acquisition and control system to continuously monitor pH, temperature and dissolved O2. The bioreactor provided superior expansion of total HSCs and not total cell number, as well as expression of stemness-related genes which followed with increasing in number of colony-forming cells during 14 days of culture compared to T -lask culture. Vertical agitation thus reduces the total cell number, which may be related to increased shear stress, but has no effect on HSC function.

18. Effective production of Biobutanol from agricultural waste (giant hogweed, hay). 2012:

Abstract: One of the main concerns regarding extensive production of bio-butanol has been associated with the high costs of the substrate (preparation of  fermentable sugars) and the relatively low tolerance of Clostridia to butanol. In this study a simple, mild approach was tested to obtain fermentable sugars from agricultural waste. Giant hogweed and hay was pre-treated with simple boiling and enzymatically hydrolysed. The results demonstrated that after adaptation of the genus Clostridium bacteria to the new substrate, the growth kinetics and sugar consumption of these bacteria we are similar to the ones obtained in traditional culture media.

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19. Bioethanol production using Yeast (S. cerevisiae) in LAMBDA MINIFOR Fermenter. 2011:

Effect of wheat gluten proteins on bioethanol yield from grain. Burešová, I., Hřivna, L., Applied Energy Volume 88, Issue 4, April 2011, Pages 1205–1210 Agrotest Fyto, Ltd., Kroměříž, Czech Republic; Mendel University in Brno, Brno, Czech Republic Keywords: Bioethanol; Triticale; Wheat; Gluten; Protein

Abstract: Bioethanol can be used as motor fuel and/or as a gasoline enhancer. A high yield feedstock for bioethanol production is cereal grain. Cereal grains containing less gluten proteins (glutenin and gliadin), but high starch, are favoured by distillers because they increase the bioethanol conversion. The direct effect of wheat gluten proteins on bioethanol yield was studied on triticale grain. Examined triticale Presto 1R.1D5+10-2 and Presto Valdy were developed by introducing selected segments of wheat chromosome 1D into triticale chromosome 1R. Even if the samples analysed in this study do not afford to make definitive assumptions, it can be noticed that in analysed cases the presence of gliadin had more significant effect on investigated parameters than the presence of glutenin. Despite the presence of glutenin subunits did not significantly decrease the investigated parameters – specific weight, Hagberg falling number and starch content in grain met the requirements for grain for bioethanol production – protein content was higher than is optimal. The fermentation experiments demonstrated good bioethanol yields but depression in grain yields caused by the presence of wheat gliadin and glutenin decreased the energy balance of Presto Valdy and Presto 1R.1D5+10-2.

20. Anaerobic fermentation of the glucose component in dates extract by yeast Saccharomyces cerevisiae. 2010:

Abstract: A process comprising of extraction, fermentation, separation and decolorization for the production of high fructose syrups and/or ethanol from dates' extract was developed. In this paper, selective fermentation of the glucose component in dates' extract by Saccharomyces cerevisiae was employed to tailor the composition of the final product (fructose- or ethanol-rich). Over 90% of dates’ sugar was extracted by water. The fermentation experiments were conducted at 30 °C and 120 rpm. The commonly marketed 55% fructose syrup was obtained at two operating conditions, i.e., low (<50%) and high (>92%) sugar conversions. Maximum fructose concentrations (77.2-78.2%) were obtained at moderately high sugar conversions (74-82%). Decolorization by activated carbon for the fructose-rich syrup resulted in 87% of color removal. Preliminary economic analysis revealed the viability of this process.

21. Anaerobic expression using the LAMBDA MINIFOR. 2007:

Abstract: The genome sequence of the non-sugar-assimilating mesophile Methanococcus maripaludis contains three genes encoding enzymes: a nonphosphorylating NADP+-dependent glyceraldehyde-3-phosphate dehydrogenase (GAPN), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), and glyceraldehyde-3-phosphate ferredoxin oxidoreductase (GAPOR); all these enzymes are potentially capable of catalyzing glyceraldehyde-3-phosphate (G3P) metabolism. GAPOR, whose homologs have been found mainly in archaea, catalyzes the reduction of ferredoxin coupled with oxidation of G3P. GAPOR has previously been isolated and characterized only from a sugar-assimilating hyperthermophile, Pyrococcus furiosus (GAPORPf), and contains the rare metal tungsten as an irreplaceable cofactor. Active recombinant M. maripaludis GAPOR (GAPORMm) was purified from Escherichia coli grown in minimal medium containing 100 μM sodium molybdate. In contrast, GAPORMm obtained from cells grown in medium containing tungsten (W) and W and molybdenum (Mo) or in medium without added W and Mo did not display any activity. Activity and transcript analysis of putative G3P-metabolizing enzymes and corresponding genes were performed with M. maripaludis cultured under autotrophic conditions in chemically defined medium. The activity of GAPORMm was constitutive throughout the culture period and exceeded that of GAPDH at all time points. As GAPDH activity was detected in only the gluconeogenic direction and GAPN activity was completely absent, only GAPORMm catalyzes oxidation of G3P in M. maripaludis. Recombinant GAPORMm is posttranscriptionally regulated as it exhibits pronounced and irreversible substrate inhibition and is completely inhibited by 1 μM ATP. With support from flux balance analysis, it is concluded that the major physiological role of GAPORMm in M. maripaludis most likely involves only nonoptimal growth conditions.

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22.  pH and temperature continuously recorded with the LAMBDA MINIFOR and SIAM software. 2005:

Abstract: The genome sequence of the non-sugar-assimilating mesophile Methanococcus maripaludis contains three genes encoding enzymes: a nonphosphorylating NADP+-dependent glyceraldehyde-3-phosphate dehydrogenase (GAPN), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), and glyceraldehyde-3-phosphate ferredoxin oxidoreductase (GAPOR); all these enzymes are potentially capable of catalyzing glyceraldehyde-3-phosphate (G3P) metabolism. GAPOR, whose homologs have been found mainly in archaea, catalyzes the reduction of ferredoxin coupled with oxidation of G3P. GAPOR has previously been isolated and characterized only from a sugar-assimilating hyperthermophile, Pyrococcus furiosus (GAPORPf), and contains the rare metal tungsten as an irreplaceable cofactor. Active recombinant M. maripaludis GAPOR (GAPORMm) was purified from Escherichia coli grown in minimal medium containing 100 μM sodium molybdate. In contrast, GAPORMm obtained from cells grown in medium containing tungsten (W) and W and molybdenum (Mo) or in medium without added W and Mo did not display any activity. Activity and transcript analysis of putative G3P-metabolizing enzymes and corresponding genes were performed with M. maripaludis cultured under autotrophic conditions in chemically defined medium. The activity of GAPORMm was constitutive throughout the culture period and exceeded that of GAPDH at all time points. As GAPDH activity was detected in only the gluconeogenic direction and GAPN activity was completely absent, only GAPORMm catalyzes oxidation of G3P in M. maripaludis. Recombinant GAPORMm is posttranscriptionally regulated as it exhibits pronounced and irreversible substrate inhibition and is completely inhibited by 1 μM ATP. With support from flux balance analysis, it is concluded that the major physiological role of GAPORMm in M. maripaludis most likely involves only nonoptimal growth conditions.

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23. Bioreactors - An overview of the innovations implemented in MINIFOR bioreactors. 2003:

Abstract: A major effort has been invested in making bioreactors more efficient. The goal has been achieved in several steps. Firstly, a replacement of the traditional rotation movement by an oscillating up and down movement of stirring discs driven by an electromagnet yields several important advantages. A soft, whole volume movement of the medium results in optimal gas distribution throughout the medium and is also advantageous for cell growth. No vortex is formed and the elimination of baffles simplifies the construction of the bioreactor. A single silicone membrane efficiently replaces traditional seals and assures perfect sterility. In the case of extremely sensitive cells gas distribution tubing can be wound on a spiral fixed to the axis. The up and down movement facilitates the gas transfer and simultaneously provides a gentle movement of the medium. Secondly, a new heat radiation system has also been introduced. A heating spiral in a gilded parabolic reflector has been placed under the bottom of the vessel. The IR rays efficiently heat up the culture without overheating it at any volume of medium. Several innovations allow the construction of high quality bioreactors at lower cost.

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