Fold Improvement (fold + improvement)

Distribution by Scientific Domains


Selected Abstracts


Comparison of Commercial Enzymes for the Processing of Marula Pulp, Wine, and Spirits

JOURNAL OF FOOD SCIENCE, Issue 6 2002
M. Fundira
ABSTRACT: Commercial enzymes were compared in this study to improve the yield and clarification of marula fruit (Sclerocarya berria sub. caffra) juice. An increase in yield of up to 12% in juice treated with the enzyme Rapidase Filtration was recorded. A 15-fold improvement in juice clarity and an increase in total terpenes were observed after treatment with prefermentation processing enzymes. Post-fermented marula wine was treated with enzymes to hydrolyze bound monoterpenes. An increase in the free monoterpenes of at least 92% was observed in enzyme-treated juice. The different enzymes had both positive and negative effects on the flavor of the juice, wine, and distillate. Trenolin Bukett increased the aroma profile of the wine, while it remained closely related to the unaltered marula profile of the control. AR2000 had an overwhelming effect on the flavor profile, but the risk of deviating from the typical marula flavor was high. [source]


Accessible proteomics space and its implications for peak capacity for zero-, one- and two-dimensional separations coupled with FT-ICR and TOF mass spectrometry

JOURNAL OF MASS SPECTROMETRY (INCORP BIOLOGICAL MASS SPECTROMETRY), Issue 3 2006
Jennifer L. Frahm
The number and wide dynamic range of components found in biological matrixes present several challenges for global proteomics. In this perspective, we will examine the potential of zero-dimensional (0D), one-dimensional (1D), and two-dimensional (2D) separations coupled with Fourier-transform ion cyclotron resonance (FT-ICR) and time-of-flight (TOF) mass spectrometry (MS) for the analysis of complex mixtures. We describe and further develop previous reports on the space occupied by peptides, to calculate the theoretical peak capacity available to each separations-mass spectrometry method examined. Briefly, the peak capacity attainable by each of the mass analyzers was determined from the mass resolving power (RP) and the m/z space occupied by peptides considered from the mass distribution of tryptic peptides from National Center for Biotechnology Information's (NCBI's) nonredundant database. Our results indicate that reverse-phase-nanoHPLC (RP-nHPLC) separation coupled with FT-ICR MS offers an order of magnitude improvement in peak capacity over RP-nHPLC separation coupled with TOF MS. The addition of an orthogonal separation method, strong cation exchange (SCX), for 2D LC-MS demonstrates an additional 10-fold improvement in peak capacity over 1D LC-MS methods. Peak capacity calculations for 0D LC, two different 1D RP-HPLC methods, and 2D LC (with various numbers of SCX fractions) for both RP-HPLC methods coupled to FT-ICR and TOF MS are examined in detail. Peak capacity production rates, which take into account the total analysis time, are also considered for each of the methods. Furthermore, the significance of the space occupied by peptides is discussed. Copyright © 2006 John Wiley & Sons, Ltd. [source]


On-line concentration by field-enhanced sample injection with reverse migrating micelles in micellar electrokinetic capillary chromatography for the analysis of coumarins from traditional Chinese medicine and human serum

BIOMEDICAL CHROMATOGRAPHY, Issue 6 2010
Ting-Fu Jiang
Abstract In this work, a simple, reproducible and sensitive micellar electrokinetic chromatography method was developed for the separation and determination of three coumarins, imperatorin (IM), isoimperatorin (IO) and osthole (OS) from traditional Chinese medicine and human serum. Field-enhanced sample injection with reverse migrating micelles was used for on-line concentration of the coumarins. The optimum buffer contained 50,mM H3PO4, 160,mM sodium dodecyl sulfate, 20% acetonitrile and 15% 2-propanol, and the pH of buffer was 2.0. The sample solution was diluted with water containing 5,mM sodium dodecyl sulfate and injected for 15,s with ,8,kV after injection of 2,s water plug. The effects of concentrations of sodium dodecyl sulfate and organic modifier, the sample matrix, the injection time of water plug, the injection voltage and injection time of sample on the separation and stacking efficiency were investigated. Under the optimum conditions, the analytes were well separated and by optimizing the stacking conditions, about 93, 195 and 136 fold improvement in the detection sensitivity was obtained for IM, IO and OS. The contents of three coumarins in Angelica dahurica Benth, Radix Angelicae Pubescentis and Fructus Cnidii were successfully determined with satisfactory repeatability and recovery. The possibilities of using this method for the determination of three coumarins in spiked human serum were also tested. Copyright © 2009 John Wiley & Sons, Ltd. [source]


Clinical scale ex vivo manufacture of neutrophils from hematopoietic progenitor cells

BIOTECHNOLOGY & BIOENGINEERING, Issue 4 2009
Nicholas E. Timmins
Abstract Dose-intensive chemotherapy results in an obligatory period of severe neutropenia during which patients are at high risk of infection. While patient support with donor neutrophils is possible, this option is restricted due to donor availability and logistic complications. To overcome these problems, we explored the possibility of large scale ex vivo manufacture of neutrophils from hematopoietic progenitor cells (HPC). CD34+ HPC isolated from umbilical cord blood (UCB) and mobilized peripheral blood (mPB) were expanded in serum-free medium supplemented with stem cell factor, granulocyte colony stimulating factor, and a thrombopoietin peptide mimetic. After 15 days of cultivation a 5,800-fold expansion in cell number was achieved for UCB, and up to 4,000-fold for mPB, comprising 40% and 60% mature neutrophils respectively. Ex vivo expanded neutrophils exhibited respiratory burst activity similar to that for donor neutrophils, and were capable of killing Candida albicans in vitro. These yields correspond to a more than 10-fold improvement over current methods, and are sufficient for the production of multiple neutrophil transfusion doses per HPC donation. To enable clinical scale manufacture, we adapted our protocol for use in a wave-type bioreactor at a volume of 10,L. This is the first demonstration of a large scale bioprocess suitable for routine manufacture of a mature blood cell product from HPC, and could enable prophylactic neutrophil support for chemotherapy patients. Biotechnol. Bioeng. 2009; 104: 832,840 © 2009 Wiley Periodicals, Inc. [source]


Efficient experimental design and micro-scale medium enhancement of 6-deoxyerythronolide B production through Escherichia coli

BIOTECHNOLOGY PROGRESS, Issue 5 2009
Michael Pistorino
Abstract The recent use of heterologous hosts to produce natural products has shown significant potential, although limitations still exist regarding optimal production titers. In this study, we utilize micro-scale cultures and well-defined screening methods to identify key medium components that influence the heterologous production of the complex polyketide 6-deoxyerythronolide B (6dEB) through E. coli. It was determined that tryptone had a significant effect on 6dEB production and could supplement substrate requirements and improve recombinant protein levels of the essential deoxyerythronolide B synthase (DEBS) which catalyze 6dEB conversion. As a result, the study (1) demonstrates the feasibility of micro-scale cultures to study E. coli 6dEB production and effectively model larger-scale cultures; (2) identifies an enhanced medium which generates over 160 mg L,1 6dEB (a 22-fold improvement over current culture media); and (3) provides new insight and understanding related to the heterologous production of 6dEB from E. coli. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009 [source]


Development of a cytokine analog with enhanced stability using computational ultrahigh throughput screening

PROTEIN SCIENCE, Issue 5 2002
Peizhi Luo
Abstract Granulocyte-colony stimulating factor (G-CSF) is used worldwide to prevent neutropenia caused by high-dose chemotherapy. It has limited stability, strict formulation and storage requirements, and because of poor oral absorption must be administered by injection (typically daily). Thus, there is significant interest in developing analogs with improved pharmacological properties. We used our ultrahigh throughput computational screening method to improve the physicochemical characteristics of G-CSF. Improving these properties can make a molecule more robust, enhance its shelf life, or make it more amenable to alternate delivery systems and formulations. It can also affect clinically important features such as pharmacokinetics. Residues in the buried core were selected for optimization to minimize changes to the surface, thereby maintaining the active site and limiting the designed protein's potential for antigenicity. Using a structure that was homology modeled from bovine G-CSF, core designs of 25,34 residues were completed, corresponding to 1021,1028 sequences screened. The optimal sequence from each design was selected for biophysical characterization and experimental testing; each had 10,14 mutations. The designed proteins showed enhanced thermal stabilities of up to 13°C, displayed five-to 10-fold improvements in shelf life, and were biologically active in cell proliferation assays and in a neutropenic mouse model. Pharmacokinetic studies in monkeys showed that subcutaneous injection of the designed analogs results in greater systemic exposure, probably attributable to improved absorption from the subcutaneous compartment. These results show that our computational method can be used to develop improved pharmaceuticals and illustrate its utility as a powerful protein design tool. [source]