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CE, long a staple in analytical chemistry for molecular separations, has recently been adapted for separating heterogeneous mixtures of microbial cells based on intrinsic differences in cell morphology and surface charge. In this application, CE enables effective separations of both relatively broad categories of cells, as well as of more similar cell types. As a phenotypic approach, CE may be less applicable to certain populations, including those comprised of pleiomorphic cells or chain-forming cells, where differences in cell size, shape, or chain length may lead to broad, "unfocusable" distributions in cell surface charge. At the other end of the spectrum, closely related species having similar surface charge profiles may not be separable via CE alone. Successful combination of microbial CE with a compatible method for generating cell-specific signals could address these limitations, increasing the diagnostic power of this approach. Fluorescence in situ hybridization (FISH) is a rapid molecular technique for fluorescence-based labeling of whole target cells. In this work, we combined a simple CE-based presence/absence test with FISH to develop a bacterial detection assay having an additional "layer" of molecular specificity. Using this approach, we were able to differentiate Salmonella Typhimurium from Escherichia coli in mixed populations via CE. Both hybridizations and CE run times were short (10-15 min), bacterial populations were highly focused ( approximately 2-3 s peak width) and there was no need for a posthybridization wash step. As few as three injected cells of S. Typhimurium were detected against a background of approximately 300 injected E. coli cells, suggesting the possibility for single-cell detection of pathogens using this technique. This proof of concept study highlights the potential of CE-FISH as a promising new tool for molecular detection of specific bacterial cells within mixtures of closely related, physiologically inseparable populations. 相似文献
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Andrew G McDonald Sinéad Boyce Gerard P Moss Henry BF Dixon Keith F Tipton 《BMC biochemistry》2007,8(1):14
Background
We describe the database ExplorEnz, which is the primary repository for EC numbers and enzyme data that are being curated on behalf of the IUBMB. The enzyme nomenclature is incorporated into many other resources, including the ExPASy-ENZYME, BRENDA and KEGG bioinformatics databases. 相似文献3.
Debjani?Mitra Anthony?L.?PomettoIII Samir?K.?Khanal Bishnu?Karki Byron?F.?Brehm-Stecher J.??van?Leeuwen 《Applied biochemistry and biotechnology》2010,162(7):1819-1833
The objective of this study was to evaluate the potential of low/negative value soy whey (SW) as an alternative, inexpensive
fermentation substrate to culture Lactococcus lactis subsp. lactis for nisin production. Initially, a microtiter plate assay using a Bioscreen C Microbiology Plate Reader was used for rapid
optimization of culture conditions. Various treatments were examined in efforts to optimize nisin production from SW, including
different methods for SW sterilization, ultrasonication of soy flake slurries for possible nutrient release, comparison of
diluted and undiluted SW, and supplementation of SW with nutrients. In subsequent flask-based experiments, dry bacterial mass
and nisin yields obtained from SW were 2.18 g/L and 619 mg/L, respectively, as compared to 2.17 g/L and 672 mg/L from a complex
medium, de Man–Rogosa–Sharpe broth. Ultrasonication of soybean flake slurries (10% solid content) in water prior to production
of SW resulted in ∼2% increase in biomass yields and ∼1% decrease in nisin yields. Nutrient supplementation to SW resulted
in ∼3% and ∼7% increase in cell and nisin yields, respectively. This proof-of-concept study demonstrates the potential for
use of a low/negative value liquid waste stream from soybean processing for production of a high-value fermentation end product. 相似文献
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M Julia BF Flaminio Alexandre S Borges Daryl V Nydam David W Horohov Rolf Hecker Mary Beth Matychak 《Journal of immune based therapies and vaccines》2007,5(1):1-17
Background
Cytosine-phosphate-guanosine oligodeoxynucleotide (CpG-ODN) has been used successfully to induce immune responses against viral and intracellular organisms in mammals. The main objective of this study was to test the effect of CpG-ODN on antigen presenting cells of young foals. 相似文献
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