EFFECTS OF VEGETABLE TANNINS ON GLUCOSE OXIDATION BY VARIOUS MICROORGANISMS

1966 ◽  
Vol 12 (4) ◽  
pp. 787-794 ◽  
Author(s):  
J. Basaraba
Keyword(s):  
Escherichia Coli ◽  
Saccharomyces Cerevisiae ◽  
Energy Source ◽  
Pseudomonas Fluorescens ◽  
Glucose Oxidation ◽  
Glucose Utilization ◽  
Resting Cells ◽  
E Coli ◽  
Vegetable Tannins ◽  
Chestnut Wood

The effects of purified tannin preparations of chestnut wood and of wattle bark on the respiration of resting cells of microorganisms were measured in a Warburg apparatus. Tannins were tested at 0.5% (w/v) concentration alone and in mixtures with glucose which provided energy for the microorganisms. In presence of the chestnut and wattle tannins, the exogenous respiration of Asotobacter vinelandii was reduced by 50 and 85% and that of Escherichia coli by 40 and 20%, respectively; respiration of Azatobacler chroococcum was completely inhibited by either tannin. Glucose oxidation by Rhizobium melioti, Rhisobium sp., and Saccharomyces cerevisiae was inhibited by tannins to small degrees. Tannins had no effect on glucose utilization by Rhodotorula sp. and Pseudomonas fluorescens. A. vinelandii, E. coli, and P. fluorescens utilized tannins, especially wattle, as an energy source.

Inhibition of Escherichia coli Trimethylamine-N-oxide Reductase by Food Preservatives1

1982 ◽  
Vol 45 (3) ◽  
pp. 241-243 ◽  
Author(s):  
M. KRUK ◽  
J. S. LEE
Keyword(s):  
Escherichia Coli ◽  
Benzoic Acid ◽  
Sorbic Acid ◽  
Reductase Activity ◽  
Resting Cells ◽  
E Coli

Trimethylamine-N-oxide (TMA-O) reductase activity of resting cells of Escherichia coli was inhibited by tetrasodium ethylenediaminetetraacetate (Na4EDTA), benzoic acid (BA and methylparaben (MP). The 50% inhibitory concentrations of Na4EDTA, BA and MP were 20.2, 1.2 and 32.4 mM, respectively. BA at pH 6.5 or below most effectively inhibited the TMA-O reductase. Sorbic acid (SA), up to 0.70 mM, had no effect on TMA-O reductase activity, but SA inhibited the growth and subsequent TMA production in E. coli at or above 0.3S mM.

scholarly journals Separation and Detection of Escherichia coli and Saccharomyces cerevisiae Using a Microfluidic Device Integrated with an Optical Fibre

Biosensors ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 40
Author(s):  
Mohd Kamuri ◽  
Zurina Zainal Abidin ◽  
Mohd Yaacob ◽  
Mohd Hamidon ◽  
Nurul Md Yunus ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Saccharomyces Cerevisiae ◽  
Optical Fibre ◽  
Flow Rate ◽  
Incident Light ◽  
Microfluidic Channel ◽  
Integrated System ◽  
Time Range ◽  
Constant Frequency ◽  
E Coli

This paper describes the development of an integrated system using a dry film resistant (DFR) microfluidic channel consisting of pulsed field dielectrophoretic field-flow-fractionation (DEP-FFF) separation and optical detection. The prototype chip employs the pulse DEP-FFF concept to separate the cells (Escherichia coli and Saccharomyces cerevisiae) from a continuous flow, and the rate of release of the cells was measured. The separation experiments were conducted by changing the pulsing time over a pulsing time range of 2–24 s and a flow rate range of 1.2–9.6 μ L min − 1 . The frequency and voltage were set to a constant value of 1 M Hz and 14 V pk-pk, respectively. After cell sorting, the particles pass the optical fibre, and the incident light is scattered (or absorbed), thus, reducing the intensity of the transmitted light. The change in light level is measured by a spectrophotometer and recorded as an absorbance spectrum. The results revealed that, generally, the flow rate and pulsing time influenced the separation of E. coli and S. cerevisiae. It was found that E. coli had the highest rate of release, followed by S. cerevisiae. In this investigation, the developed integrated chip-in-a lab has enabled two microorganisms of different cell dielectric properties and particle size to be separated and subsequently detected using unique optical properties. Optimum separation between these two microorganisms could be obtained using a longer pulsing time of 12 s and a faster flow rate of 9.6 μ L min − 1 at a constant frequency, voltage, and a low conductivity.

scholarly journals RNA minihelices as model substrates for ATP/CTP:tRNA nucleotidyltransferase

1997 ◽  
Vol 327 (3) ◽  
pp. 847-851 ◽  
Author(s):  
Zengji LI ◽  
Yue SUN ◽  
L. David THURLOW
Keyword(s):  
Escherichia Coli ◽  
Saccharomyces Cerevisiae ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Single Base ◽  
Three Dimensional Structure ◽  
E Coli ◽  
Base Identity

Twenty-one RNA minihelices, resembling the coaxially stacked acceptor- /T-stems and T-loop found along the top of a tRNA's three-dimensional structure, were synthesized and used as substrates for ATP/CTP:tRNA nucleotidyltransferases from Escherichia coli and Saccharomyces cerevisiae. The sequence of nucleotides in the loop varied at positions corresponding to residues 56, 57 and 58 in the T-loop of a tRNA. All minihelices were substrates for both enzymes, and the identity of bases in the loop affected the interaction. In general, RNAs with purines in the loop were better substrates than those with pyrimidines, although no single base identity absolutely determined the effectiveness of the RNA as substrate. RNAs lacking bases near the 5ʹ-end were good substrates for the E. coli enzyme, but were poor substrates for that from yeast. The apparent Km values for selected minihelices were 2-3 times that for natural tRNA, and values for apparent Vmax were lowered 5-10-fold.

scholarly journals Microbial diversity beyond E. coli: new microbial worlds, new concepts in biology

2011 ◽  
Vol 32 (2) ◽  
pp. 73
Author(s):  
John A Fuerst
Keyword(s):  
Escherichia Coli ◽  
Saccharomyces Cerevisiae ◽  
Influenza Virus ◽  
Microbial Diversity ◽  
Microbial Evolution ◽  
E Coli ◽  
New Concepts ◽  
Wide Range ◽  
Classical Models ◽  
The Universe

Microbial diversity explores the universe of microorganisms beyond classical models such as Escherichia coli, influenza virus, or Saccharomyces cerevisiae. Exploring such new microbial worlds is essential for a microbiology which needs to learn about all the scientific and practical possibilities offered by billions of years of microbial evolution. Here we illustrate some examples of how studying a wide range of microbial diversity can assist microbiology as a fundamental and a practical science.

scholarly journals Effects of antibacterial compound of Saccharomyces cerevisiae from koumiss on immune function and caecal microflora of mice challenged with pathogenic Escherichia coli O8

2019 ◽  
Vol 88 (2) ◽  
pp. 233-241
Author(s):  
Yujie Chen ◽  
Chen Aorigele ◽  
Chunjie Wang ◽  
Wenqian Hou ◽  
Yunsheng Zheng ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Saccharomyces Cerevisiae ◽  
Immune Function ◽  
T Lymphocyte ◽  
Lymphocyte Subsets ◽  
Clinical Symptoms ◽  
Pathological Changes ◽  
T Lymphocyte Subsets ◽  
E Coli ◽  
Antibacterial Compound

The yeast Saccharomyces cerevisiae from koumiss has been shown to have antibacterial effects on Escherichia coli, possibly by producing antibacterial compound in metabolism; however, there is limited knowledge about its application in animal production. We therefore investigated the effects of an antibacterial compound of S. cerevisiae from koumiss on the immune function and caecal microflora of mice challenged with pathogenic Escherichia coli O8. Three groups were formed: negative control (NC), positive control (PC), and the antibacterial compound of S. cerevisiae at pH 2.0 (S2). Mice in the NC and PC groups were orally administered phosphate buffer solution (PBS) for 7 d. At 4 d, E. coli O8 was administered intraperitoneally in group PC. Mice in group S2 were first administered orally as mice in group NC, and subsequently intraperitoneally administered E. coli O8 as mice in group PC. Compared with the NC group, mice in the PC group displayed clinical symptoms and pathological changes in the small intestine. Small intestine villi in the S2 group also developed some histologically pathological changes but not as severe as in the PC group. Moreover, there was less mortality in the S2 group than in the PC group. In PC group, thymus indexes, immunoglobulin A (IgA) in serum and Bifidobacterium in caecum were decreased and E. coli in the caecum was increased. In the S2 group, CD8+ of T lymphocyte subsets in blood and Bifidobacterium in caecum were decreased, while spleen indexes, IgG, IgM in serum, and CD3+ of T lymphocyte subsets in blood were increased. This suggests that S2 can relieve clinical symptoms of mice challenged with pathogenic E. coli O8, enhance their immune function, and influence their caecal microflora. The study will provide a theoretical foundation for utilizing antibacterial compound of S. cerevisiae from koumiss for curative purposes.

scholarly journals Cloning of Phanerochaete chrysosporium leu2 by Complementation of Bacterial Auxotrophs and Transformation of Fungal Auxotrophs

1998 ◽  
Vol 64 (7) ◽  
pp. 2624-2629 ◽  
Author(s):  
Laura Schick Zapanta ◽  
Takefumi Hattori ◽  
Magarita Rzetskaya ◽  
Ming Tien
Keyword(s):  
Escherichia Coli ◽  
Saccharomyces Cerevisiae ◽  
Phanerochaete Chrysosporium ◽  
Expression Vector ◽  
Selectable Marker ◽  
Genomic Clone ◽  
Selectable Markers ◽  
E Coli ◽  
Number Of Genes ◽  
Isopropylmalate Dehydrogenase

ABSTRACT A Phanerochaete chrysosporium cDNA library was constructed in an expression vector that allows expression in bothEscherichia coli and Saccharomyces cerevisiae. This expression vector, λYES, contains the lacZ promoter for expression in E. coli and the GAL1 promoter for expression in yeast. A number of genes were cloned by complementation of bacterial amino acid auxotrophs. The cDNA encoding the β-isopropylmalate dehydrogenase from P. chrysosporiumwas characterized further. The genomic clone (gleu2) was subsequently isolated and was used successfully as a selectable marker to transform P. chrysosporium auxotrophs for LEU2. Protoplasts for transformation were prepared with readily obtained conidiospores rather than with basidiospores, which were used in previous P. chrysosporium transformation procedures. The method described here allows other genes to be isolated from P. chrysosporium for use as selectable markers.

Spread of Marker Bacteria from the Hides of Cattle in a Simulated Livestock Market and at an Abattoir

2004 ◽  
Vol 67 (11) ◽  
pp. 2397-2402 ◽  
Author(s):  
V. J. COLLIS ◽  
C.-A. REID ◽  
M. L. HUTCHISON ◽  
M. H. DAVIES ◽  
K. P. A. WHEELER ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Fluorescens ◽  
Nalidixic Acid ◽  
Microbial Contamination ◽  
Market Process ◽  
Market Environment ◽  
E Coli ◽  
Environmental Surfaces ◽  
K 12 ◽  
Two Stages

The spread of microbial contamination on the hides of beef was investigated at two stages in the meat chain: (i) in a simulated livestock market (“the market”) using 33 animals, and (ii) in the unloading-to-skinning area of a commercial abattoir using 18 animals. At both stages, harmless bacterial markers (nalidixic acid–resistant Escherichia coli K-12; rifampicin- and nalidixic acid–resistant Pseudomonas fluorescens; and a tetracycline-resistant E. coli) were inoculated on the hides of a small number of selected animals, and their transfer to other animals and the environment was examined. At the market, the initial prevalence of animals positive for the hide markers (9.1% in each phase) introduced in the presale pen, sale ring, and postsale pen changed to 39.4, 15.1, and 54.5%, respectively, by the end of the market process. In addition, widespread contamination of the market environment with the hide markers was observed. At the abattoir, the initial prevalence of animals positive for the hide marker (11.1%) inoculated at unloading increased to 100% (hide before skinning) and 88.8% (skinned carcass). In addition, another marker inoculated on environmental surfaces in lairage pens, races, and stunning box was detected on 83.3% (hide before skinning) and 88.8% (skinned carcass). These results, although obtained with a relatively small number of animals, demonstrate that both the livestock market process and the unloading-to-skinning process at abattoirs can facilitate the extensive spread of microbial contamination on hides not just within, but also between, batches of animals.

Activity of Goats' Milk Lactoperoxidase System on Pseudomonas fluorescens and Escherichia coli at Refrigeration Temperatures

1995 ◽  
Vol 58 (10) ◽  
pp. 1136-1138 ◽  
Author(s):  
PALOMA ZAPICO ◽  
PILAR GAYA ◽  
MANUEL NUÑEZ ◽  
MARGARITA MEDINA
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Fluorescens ◽  
Bactericidal Activity ◽  
Inhibitory Activity ◽  
Initial Level ◽  
Lag Phase ◽  
E Coli ◽  
Lactoperoxidase System ◽  
System Activation ◽  
Control Milk

Bactericidal activity of the lactoperoxidase (LP) system against Pseudomonas fluorescens was observed in refrigerated raw goats' milk. Mean decreases in the levels of P. fluorescens of 1.69 log units at 4°C and 1.85 log units at 8°C were achieved during the first 24 h by LP-system activation. Inhibitory activity depended on temperature and length of incubation. P. fluorescens counts lower than the initial level were recorded in activated LP-system milk for 5 days at 4°C and 3 days at 8°C. Escherichia coli did not grow in raw goats' milk at 4°C, and the influence of LP-system activation at this temperature on E. coli counts was negligible. At 8°C, E. coli was able to grow in control milk with no apparent lag phase. In contrast, a lag phase of 2 days was observed in activated LP-system milk at 8°C, resulting in lower E. coli counts than those of control milk during the first 5 days.

scholarly journals Cloning of Thalassiosira pseudonana’s Mitochondrial Genome in Saccharomyces cerevisiae and Escherichia coli

Biology ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 358
Author(s):  
Ryan R. Cochrane ◽  
Stephanie L. Brumwell ◽  
Arina Shrestha ◽  
Daniel J. Giguere ◽  
Samir Hamadache ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Saccharomyces Cerevisiae ◽  
Mitochondrial Genome ◽  
Phaeodactylum Tricornutum ◽  
Genome Engineering ◽  
Genome Instability ◽  
Thalassiosira Pseudonana ◽  
Genome Integrity ◽  
Mitochondrial Genomes ◽  
E Coli

Algae are attractive organisms for biotechnology applications such as the production of biofuels, medicines, and other high-value compounds due to their genetic diversity, varied physical characteristics, and metabolic processes. As new species are being domesticated, rapid nuclear and organelle genome engineering methods need to be developed or optimized. To that end, we have previously demonstrated that the mitochondrial genome of microalgae Phaeodactylum tricornutum can be cloned and engineered in Saccharomyces cerevisiae and Escherichia coli. Here, we show that the same approach can be used to clone mitochondrial genomes of another microalga, Thalassiosira pseudonana. We have demonstrated that these genomes can be cloned in S. cerevisiae as easily as those of P. tricornutum, but they are less stable when propagated in E. coli. Specifically, after approximately 60 generations of propagation in E. coli, 17% of cloned T. pseudonana mitochondrial genomes contained deletions compared to 0% of previously cloned P. tricornutum mitochondrial genomes. This genome instability is potentially due to the lower G+C DNA content of T. pseudonana (30%) compared to P. tricornutum (35%). Consequently, the previously established method can be applied to clone T. pseudonana’s mitochondrial genome, however, more frequent analyses of genome integrity will be required following propagation in E. coli prior to use in downstream applications.

scholarly journals Susceptibility of Escherichia coli, Salmonella sp. and Clostridium perfringensto organic acids and monolaurin

2012 ◽  
Vol 51 (No. 3) ◽  
pp. 81-88 ◽  
Author(s):  
E. Skrivanova ◽  
M. Marounek ◽  
V. Benda ◽  
P. Brezina
Keyword(s):  
Escherichia Coli ◽  
Fatty Acids ◽  
Antimicrobial Activity ◽  
Organic Acids ◽  
Lauric Acid ◽  
Caprylic Acid ◽  
Glucose Utilization ◽  
E Coli ◽  
Medium Chain ◽  
Medium Chain Fatty Acids

The antimicrobial activity of fatty acids, monolaurin, citric, succinic, fumaric, malic and lactic acid was determined in cultures of two strains of Escherichia coli, three strains of Salmonella sp. and two strains of Clostridium perfringens. Antimicrobial activity was expressed as minimum inhibitory concentration (MIC) that prevented growth and glucose utilization in treated cultures. Caprylic acid was the only acid inhibiting glucose utilization in all cultures. Its MIC varied from 1 to 3 mg/ml. Strains CCM 3954 and CCM 4225 of E. coli were inhibited also by capric acid at 5 mg/ml. Strains CCM 4435<sup>T </sup>and CNCTC 5459 of Cl. perfringens were inhibited by medium-chain fatty acids (C<sub>8</sub> to C<sub>14</sub>), oleic acid and one strain also by linoleic acid. The minimum MICs were those of lauric and myristic acid (between 0.1 and 0.2 mg/ml). Growth of Cl. perfringens, but not other bacteria, was inhibited also by monoglyceride of lauric acid (MIC = 3 mg/ml), and by citric acid (MIC = 4 mg/ml). Inhibitory effects of other acids were not observed at 5 mg/ml. Caprylic and lauric acid did not influence the K<sup>+ </sup>permeability of the cytoplasmic membrane in cells of E. coli CCM 4225 and Cl. perfringens CCM 4435<sup>T</sup>, respectively. In cultures of both strains of E. coli treated with caprylic acid at 5 mg/ml, and in those of Cl. perfringens CCM 4435<sup>T </sup>treated with lauric acid at 1 mg/ml, or with its monoglyceride at 5 mg/ml, the transmission electron microscopy revealed damage of cytoplasmatic structures. In cells of Cl. perfringens the separation of inner and outer membranes was apparent, the integrity of the outer membrane, however, was maintained. It can be concluded that medium-chain fatty acids are more efficient antimicrobials than other, more polar organic acids tested.

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