UTILIZATION OF CARBOHYDRATES BY ACTINOBACILLUS MALLEI

1966 ◽  
Vol 12 (4) ◽  
pp. 625-639 ◽  
Author(s):  
D. H. Evans
Keyword(s):  
Methylene Blue ◽  
Nitrogen Source ◽  
Ammonium Chloride ◽  
Carbon Sources ◽  
Defined Medium ◽  
Ammonium Citrate ◽  
Chemically Defined Medium ◽  
Negative Results ◽  
Proteose Peptone ◽  
Positive Results

Twenty-three substrains representing colonial variants of 11 strains of Actinabacillus mallei were examined for their ability to attack carbohydrates. Tests conducted in a basal liquid complex medium, containing yeast extract and proteose peptone No. 3 with bromcresol purple as indicator, showed that all strains tested produced acid from arabinose, glucose, fructose, galactose, mannose, and trehalose, while five substrains gave positive results with lactose, one with sucrose, and two with maltose. Eosin methylene blue agar of the same basal composition gave positive results for most of the strains grown on arabinose, glucose, fructose, galactose, mannose, and trehalose, and negative results for all strains grown on xylose, lactose, sucrose, and maltose. In a chemically defined medium containing ammonium chloride as nitrogen source and bromcresol purple as indicator, acid was produced by eight substrains of five of these strains from glucose, galactose, mannose, and trehalose, and by several strains from fructose and sucrose. The ability of these five selected strains to utilize carbohydrates as sole carbon sources for growth was tested in a chemically defined medium containing ammonium citrate as nitrogen source. All strains were able to grow on glucose, galactose, mannose, and trehalose, and most were able to grow on fructose. Arabinose, xylose, lactose, sucrose, and maltose did not support the growth of any of the strains tested.

scholarly journals Physiological Study of Lactobacillus delbrueckii subsp. bulgaricus Strains in a Novel Chemically Defined Medium

2000 ◽  
Vol 66 (12) ◽  
pp. 5306-5311 ◽  
Author(s):  
Christian Chervaux ◽  
S. Dusko Ehrlich ◽  
Emmanuelle Maguin
Keyword(s):  
Carbon Sources ◽  
Streptococcus Thermophilus ◽  
Defined Medium ◽  
Lactobacillus Delbrueckii ◽  
Protein Labeling ◽  
Chemically Defined Medium ◽  
Phosphotransferase System ◽  
Nutritional Conditions ◽  
Labeling Method

ABSTRACT We developed a chemically defined medium called milieu proche du lait (MPL), in which 22 Lactobacillus delbrueckii subsp.bulgaricus (L. bulgaricus) strains exhibited growth rates ranging from 0.55 to 1 h−1. MPL can also be used for cultivation of other lactobacilli and Streptococcus thermophilus. The growth characteristics of L. bulgaricus in MPL containing different carbon sources were determined, including an initial characterization of the phosphotransferase system transporters involved. For the 22 tested strains, growth on lactose was faster than on glucose, mannose, and fructose. Lactose concentrations below 0.4% were limiting for growth. We isolated 2-deoxyglucose-resistant mutants from strains CNRZ397 and ATCC 11842. CNRZ397-derived mutants were all deficient for glucose, fructose, and mannose utilization, indicating that these three sugars are probably transported via a unique mannose-specific-enzyme-II-like transporter. In contrast, mutants of ATCC 11842 exhibited diverse phenotypes, suggesting that multiple transporters may exist in that strain. We also developed a protein labeling method and verified that exopolysaccharide production and phage infection can occur in MPL. The MPL medium should thus be useful in conducting physiological studies ofL. bulgaricus and other lactic acid bacteria under well controlled nutritional conditions.

Nitrogen source regulates expression of alanine dehydrogenase isoenzymes in Streptomyces avermitilis in a chemically defined medium

1997 ◽  
Vol 43 (2) ◽  
pp. 189-193 ◽  
Author(s):  
Jan Novák ◽  
Jan Kopecký ◽  
Zdenko Vaněk
Keyword(s):  
Nitrogen Source ◽  
Ammonium Sulfate ◽  
Alanine Aminotransferase ◽  
Specific Activity ◽  
Defined Medium ◽  
Streptomyces Avermitilis ◽  
Chemically Defined Medium ◽  
Ammonium Ions ◽  
Alanine Dehydrogenase ◽  
Dehydrogenase Reaction

Ammonium ions and alanine influence production of the macrolide avermectin in Streptomyces avermitilis. L-Alanine dehydrogenase and alanine aminotransferase are the primary enzymes responsible for regulating the intracellular concentration of alanine and also of ammonium ions. In cultures of S. avermitilis in a chemically defined medium with ammonia or L-alanine as the only nitrogen source, specific activities of both enzymes increased during growth. The alanine dehydrogenase specific activity increased more than 86-fold after the culture was supplemented with 0.2% L-alanine and 5-fold after addition of 0.5% ammonium sulfate, whereas alanine aminotransferase specific activity increased 3- to 4-fold with either substrate. Five isoenzymes of alanine dehydrogenase were detected histochemically in S. avermitilis after native gel electrophoresis. Isoenzyme 1 was induced by alanine and temporarily repressed by high concentrations of ammonium sulfate. The presence of isoenzyme 1 was also related to changes in the kinetic properties of the alanine dehydrogenase reaction measured in crude desalted extracts. A nonlinear double-reciprocal plot was obtained in initial velocity studies using L-alanine as a substrate in the sample induced with L-alanine. The nonlinearity was caused by both substrate inhibition and allosteric regulation (positive cooperativity) by L-alanine. In contrast, the sample induced by ammonium sulfate showed a linear double-reciprocal plot.Key words: isoenzymes, L-alanine dehydrogenase, Streptomyces avermitilis, avermectin.

scholarly journals The Growth Of Rhizobium in Synthetic Media

1961 ◽  
Vol 14 (3) ◽  
pp. 349 ◽  
Author(s):  
FJ Bergersen
Keyword(s):  
Amino Acids ◽  
Nitrogen Source ◽  
Exponential Growth ◽  
Defined Medium ◽  
Complete Medium ◽  
Good Growth ◽  
Chemically Defined Medium ◽  
Sodium Glutamate ◽  
Synthetic Media

A chemically defined medium for the growth of Rhizobium is described in which populations of up to 5 x 109 cells/ml were obtained. For the six strains of bacteria studied the complete medium supported exponential growth for two to five generations. The concentrations of biotin giving best growth varied ith strain between 125 and 250 f'g/l when the nitrogen source was sodium glutamate. NHt, NOs, and other amino acids, singly or in combination, did not upport as good growth as did sodium glutamate.

UTILIZATION OF SODIUM CASEINATE BY LACTIC STREPTOCOCCI AND ENTEROCOCCI

1956 ◽  
Vol 2 (6) ◽  
pp. 607-610 ◽  
Author(s):  
I. J. McDonald
Keyword(s):  
Nitrogen Source ◽  
Sodium Caseinate ◽  
Defined Medium ◽  
Starter Cultures ◽  
Sole Nitrogen Source ◽  
Chemically Defined Medium ◽  
Casein Hydrolyzate ◽  
Selection Of

The ability of lactic streptococci to utilize unhydrolyzed sodium caseinate as the nitrogen source in an otherwise chemically defined medium seems to be a strain rather than a species characteristic. This characteristic therefore appears to have little value as an aid in classification although it might have some importance in selection of starter cultures for cheese manufacture. None of the enterococci examined grew with unhydrolyzed sodium caseinate as the sole nitrogen source. However, Streptococcus liquefaciens and Streptococcus zymogenes appeared to utilize sodium caseinate when small amounts of casein hydrolyzate were added to the medium.

scholarly journals Revealing nutritional requirements of MICP-relevant Sporosarcina pasteurii DSM33 for growth improvement in chemically defined and complex media

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Frédéric M. Lapierre ◽  
Jakob Schmid ◽  
Benjamin Ederer ◽  
Nina Ihling ◽  
Jochen Büchs ◽  
...  
Keyword(s):  
Yeast Extract ◽  
Oxygen Transfer Rate ◽  
Carbon Sources ◽  
Construction Materials ◽  
Defined Medium ◽  
Nutritional Requirements ◽  
Chemically Defined Medium ◽  
Complex Media ◽  
Sporosarcina Pasteurii ◽  
Medium Components

AbstractMicrobial induced calcite precipitation (MICP) based on ureolysis has a high potential for many applications, e.g. restoration of construction materials. The gram-positive bacterium Sporosarcina pasteurii is the most commonly used microorganism for MICP due to its high ureolytic activity. However, Sporosarcina pasteurii is so far cultivated almost exclusively in complex media, which only results in moderate biomass concentrations at the best. Cultivation of Sporosarcina pasteurii must be strongly improved in order to make technological application of MICP economically feasible. The growth of Sporosarcina pasteurii DSM 33 was boosted by detecting auxotrophic deficiencies (L-methionine, L-cysteine, thiamine, nicotinic acid), nutritional requirements (phosphate, trace elements) and useful carbon sources (glucose, maltose, lactose, fructose, sucrose, acetate, L-proline, L-alanine). These were determined by microplate cultivations with online monitoring of biomass in a chemically defined medium and systematically omitting or substituting medium components. Persisting growth limitations were also detected, allowing further improvement of the chemically defined medium by the addition of glutamate group amino acids. Common complex media based on peptone and yeast extract were supplemented based on these findings. Optical density at the end of each cultivation of the improved peptone and yeast extract media roughly increased fivefold respectively. A maximum OD600 of 26.6 ± 0.7 (CDW: 17.1 ± 0.5 g/L) was reached with the improved yeast extract medium. Finally, culture performance and media improvement was analysed by measuring the oxygen transfer rate as well as the backscatter during shake flask cultivation.

Critical Evaluation of Impedance Phlebography for the Diagnosis of Deep Vein Thrombosis

1974 ◽  
Vol 31 (02) ◽  
pp. 273-278
Author(s):  
Kenneth K Wu ◽  
John C Hoak ◽  
Robert W Barnes ◽  
Stuart L Frankel
Keyword(s):  
Deep Vein Thrombosis ◽  
False Positive ◽  
False Negative ◽  
Critical Evaluation ◽  
Original Method ◽  
Vein Thrombosis ◽  
Negative Results ◽  
False Negative Results ◽  
Deep Vein ◽  
Positive Results

SummaryIn order to evaluate its daily variability and reliability, impedance phlebography was performed daily or on alternate days on 61 patients with deep vein thrombosis, of whom 47 also had 125I-fibrinogen uptake tests and 22 had radiographic venography. The results showed that impedance phlebography was highly variable and poorly reliable. False positive results were noted in 8 limbs (18%) and false negative results in 3 limbs (7%). Despite its being simple, rapid and noninvasive, its clinical usefulness is doubtful when performed according to the original method.

PET/CT WITH 68GA-PSMA-11 IN DETECTION OF PRIMARY TUMOR AND RECURRENCE OF PROSTATE CANCER

2018 ◽  
Vol 64 (6) ◽  
pp. 799-804
Author(s):  
Darya Ryzhkova ◽  
M. Poyda
Keyword(s):  
Prostate Cancer ◽  
Primary Tumor ◽  
Biochemical Recurrence ◽  
Whole Body ◽  
Negative Results ◽  
Primary Prostate Cancer ◽  
Pet Ct ◽  
The Relationship ◽  
Positive Results ◽  
T Category

Purpose: To study the diagnostic value of PET-CT with 68Ga-PSMA-11 in the diagnosis of a primary prostate cancer, preoperative staging, and the detection of recurrence of prostate cancer (PCa). Methods: 28 patients aged 64.7 ± 8.74 years were included. 10 patients primary prostate cancer, and 18 patients with biochemical recurrence of the disease after radical treatment were examined. All patients underwent PET-CT with 68Ga-PSMA-11 according the whole body protocol. Interpretation of images was performed visually and quantitatively by calculation of SUL max. Results: High focal or diffuse 68Ga-PSMA-11 uptake was found in prostate parenchyma in patients with primary prostate cancer. Additionally metastases in regional lymph nodes were diagnosed in 4 patients and bone metastases were found in one patient. The correlation between 68Ga-PSMA-11 uptake level and Gleason index in the primary tumor (R Spearmen = 0.25, p = 0.57) was not observed. PET-positive results were obtained in 14 patients and PET-negative results in 4 patients with biochemical recurrence of PCa. The relationship between the frequency of PET-positive results and Gleason index was not revealed (R Spearmen = 0.2, p = 0.39). We found a weak but significant correlation between the frequency of PET-positive results and the prostate tumor stage according to the T category (R Spearmen = 0.49, p = 0.049). In patients with low values of PSA (less than 1.0 ng/ml) in 4 out of 9 cases, PET-negative results were obtained. In patients with PSA level more than 1.0 ng/ml PET-positive results were obtained in all cases. Conclusions: PET/CT with 68Ga-PSMA-11 allows to diagnose the primary prostate cancer, to establish the stage of the disease in categories N and M, and also to determine the localization and dissemination of the tumor in patients with biochemical recurrence of prostate cancer. The relationship between 68Ga-PSMA-11 uptake in primary tumor and Gleason index was not found. The probability of obtaining PET-positive results in cases of biochemical recurrence is affected by a PSA level above 1 ng/ml and a high stage of the disease according to the T category (T3-T4).

scholarly journals Diagnostic Performance of Ankle-Brachial Pressure Index in Lower Extremity Arterial Disease

2021 ◽  
Vol 07 (03) ◽  
pp. e132-e137
Author(s):  
Mohammed Alagha ◽  
Thomas M. Aherne ◽  
Ahmed Hassanin ◽  
Adeel S. Zafar ◽  
Doireann P. Joyce ◽  
...  
Keyword(s):  
Lower Extremity ◽  
Sensitivity And Specificity ◽  
False Negative ◽  
Arterial Disease ◽  
Initial Assessment ◽  
Reference Standard ◽  
Lower Extremity Arterial Disease ◽  
Negative Results ◽  
Positive Results ◽  
Arterial Imaging

Abstract Introduction Ankle-brachial pressure indices (ABIs) continue to form the basis of diagnostics for lower extremity arterial disease (LEAD). However, there remains a paucity of data to support its accuracy. This study aims to evaluate its diagnostic sensitivity and specificity using established arterial-imaging modalities as a benchmark. Methods In this retrospective study, a regional, prospectively maintained, vascular laboratory database was interrogated to identify referred patients with arterial disease who underwent concomitant assessment with ABI and lower limb arterial duplex ultrasound (DUS). Duplex acted as the reference standard. Those who had peripheral computed tomography angiogram (CTA) within 3 months of initial assessment were included in a subgroup analysis to correlate ABI with CTA. The primary end point was the sensitivity and specificity of ABI compared with DUS as the reference standard. Results Concomitant assessment was performed in 438 limbs (250 patients) over a 27-month period. The ABI was normal (0.9 to 1.4) in 196 limbs (44.9%) and abnormal in the remaining 241 limbs (55.1%). False-positive results occurred in 83 out of 241 limbs (34.4%), and false-negative results occurred in 54 limbs out of 196 (27.5%). True-positive results were 158 out of 241 limbs (65.6%), whereas true-negative results were 142 out of 196 limbs (72.4%). ABI using DUS as a benchmark identified a sensitivity for peripheral artery disease of 72.3% and a specificity of 69.3%. Concomitant CTA imaging was available in 200 limbs. The sensitivity and specificity of ABI correlated with CTA were 65.5 and 68.8%, respectively. Conclusion ABIs have a moderate predictive value in the diagnosis of LEAD. Normal range outcomes cannot be taken to infer the absence of LEAD and, as such, further arterial imaging in the form of DUS or angiography should be strongly considered in those with suspected underlying disease requiring intervention. Further noninvasive tests such as exercise studies or pulse volume waveforms should be considered, if diagnostic uncertainty exists, in those requiring nonoperative intervention and risk factor control.

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