Production of PR Toxin and Roquefortine by Penicillium roqueforti Isolates from Cabrales Blue Cheese

1985 ◽  
Vol 48 (2) ◽  
pp. 118-121 ◽  
Author(s):  
MARGARITA MEDINA ◽  
PILAR GAYA ◽  
M. NUÑEZ
Keyword(s):  
Bacillus Stearothermophilus ◽  
Test Organism ◽  
Toxin Production ◽  
Penicillium Roqueforti ◽  
Blue Cheese ◽  
Average Production ◽  
The Mean ◽  
Layer Chromatography ◽  
Yeast Extract Sucrose ◽  
Disc Assay

PR toxin production in yeast extract-sucrose broth by 33 Penicillium roqueforti isolates from Cabrales blue cheese was quantified by a disc assay technique with Bacillus megaterium NRRL B-1368 as the test organism. Isolates from the interior of the cheese reached an average production of 1,89 mg PR toxin/100 ml, whereas the mean level of isolates from the surface was 1.64 mg/100 ml. Roquefortine production in the same broth by these isolates was quantified by a similar technique, with Bacillus stearothermophilus DSM 22 as the test organism. Mean production of roquefortine was 0.18 mg/100 ml for P. roqueforti isolates from the interior and 0.09 mg/100 ml for isolates from the surface of the cheese. If lactose or sodium lactate replaced sucrose in the growth medium, levels of both toxins decreased considerably. The identity of PR toxin and roquefortine in crude extracts was confirmed by thin-layer chromatography.

Roquefortine C Occurrence in Blue Cheese

2001 ◽  
Vol 64 (2) ◽  
pp. 246-251 ◽  
Author(s):  
CARLO FINOLI ◽  
ANGELA VECCHIO ◽  
ANTONIETTA GALLI ◽  
IVAN DRAGONI
Keyword(s):  
Yeast Extract ◽  
Culture Media ◽  
Penicillium Roqueforti ◽  
Blue Cheese ◽  
Penicillium Crustosum ◽  
Sucrose Medium ◽  
Low Toxicity ◽  
Yeast Extract Sucrose ◽  
Roquefortine C

Several strains of Penicillium are used for the production of mold-ripened cheeses, and some of them are able to produce mycotoxins. The aims of the research were the determination of roquefortine C and PR toxin in domestic and imported blue cheeses, the identification of the penicillia used as starter, and the investigation of their capacity for producing toxins in culture media. Roquefortine C was always found in the cheeses at levels ranging from 0.05 to 1.47 mg/kg, whereas the PR toxin was never found. The identification of the fungal strains present in the domestic cheeses included Penicillium glabrum, Penicillium roqueforti, and Penicillium cyclopium in the Gorgonzola “dolce” and Penicillium roqueforti in the Gorgonzola “naturale”; in one case, the presence of Penicillium crustosum was observed. The strains isolated from the foreign cheeses belonged to P. roqueforti. The strains were able to produce between 0.18 and 8.44 mg/liter of roquefortine in yeast extract sucrose medium and between 0.06 and 3.08 mg/liter and less than 0.05 mg/liter when inoculated in milk at 20°C for 14 days and 4°C for 24 days, respectively. Linear relations between production of roquefortine in culture media and cheeses did not emerge. PR toxin ranged from less than 0.05 to 60.30 mg/liter in yeast extract sucrose medium and was produced in milk at 20°C from only one strain. The low levels and the relatively low toxicity of roquefortine make the consumption of blue cheese safe for the consumer.

Determination of Residual Cephalexin in Chick Tissues by Bacillus stearothermophilus Paper Disc Assay

1988 ◽  
Vol 71 (2) ◽  
pp. 337-340
Author(s):  
Junya Okada ◽  
Ikuji Higuchi ◽  
Sadao Kondo ◽  
Bun-Ichi Saito
Keyword(s):  
Detection Limit ◽  
Trichloroacetic Acid ◽  
Bacillus Stearothermophilus ◽  
Test Organism ◽  
Acid Extract ◽  
Average Recovery ◽  
Ad Libitum ◽  
Paper Disc ◽  
Disc Assay

Abstract A paper disc method is described for determination of residual cephalexin (CEX) in chick tissues. A trichloroacetic acid extract of plasma and tissues is chromatographed on a macroreticular resin (Diaion HP-20) column to remove endogenous antibacterial substances interfering with the assay. The eluate is evaporated to dryness and the residue, dissolved in methanol-water (1 + 2), is subjected to a paper disc assay using Bacillus stearothermophilus var. calidolactis C953 NIZO as a test organism. The detection limit was 0.0375 ppm in tissue; the average recovery of CEX ranged from 72.4% in skin to 90.4% in plasma. Water containing 200 or 500 mg/L of CEX was given ad libitum to 2-week-old chicks for 10 days; the highest levels of CEX were found in the kidney, and the lowest were found in muscle at 0 h of withdrawal. CEX disappeared from most tissues at 24 h after withdrawal except from skin of chicks given 500 mg/ L. However, the drug was not detected in the skin at 48 h after withdrawal.

Identification and Determination of Four β-Lactam Antibiotics in Milk

1982 ◽  
Vol 45 (5) ◽  
pp. 450-451 ◽  
Author(s):  
DORIS V. HERBST
Keyword(s):  
Bacillus Stearothermophilus ◽  
Test Organism ◽  
Penicillin G ◽  
Diffusion Method ◽  
Phase Method ◽  
Preliminary Screening ◽  
Diffusion Technique ◽  
Three Phase ◽  
Layer Chromatography

A coordinated three-phase method was developed to determine residues of penicillin G, ampicillin, cephapirin and cloxacillin, the four β-lactam antibiotics most frequently used in mastitis preparations, in milk. An agar well diffusion technique in bioassay trays with Bacillus stearothermophilus as the test organism was used for preliminary screening. Positive samples were subjected to thin-layer chromatography followed by bioautography, and the residues were identified. An agar well diffusion method with standard levels of the specific β-lactam antibiotics was used for quantitation.

TYRAMINE, HISTAMINE, AND TRYPTAMINE CONTENT OF CHEESE

1974 ◽  
Vol 37 (7) ◽  
pp. 377-381 ◽  
Author(s):  
M. N. Voigt ◽  
R. R. Eitenmiller ◽  
P. E. Koehler ◽  
M. K. Hamdy
Keyword(s):  
Cheddar Cheese ◽  
The United States ◽  
Quantitative Information ◽  
Biologically Active ◽  
Blue Cheese ◽  
Physiological Importance ◽  
Fluorescence Measurements ◽  
Soft Cheese ◽  
Layer Chromatography ◽  
Derivatives Of

Because of the increasing knowledge of the physiological importance of biologically active amines in man and the importance of the presence of these amines in cheese, this study was done to obtain quantitative information for tyramine, tryptamine, and histamine in cheese available in the United States. The tyramine, histamine, and tryptamine contents of 156 samples of cheese purchased at retail stores were quantitated by thin-layer chromatography and fluorescence measurements of NBD-chloride derivatives of the amines. Tyramine was found in 81 of 85 Cheddar cheese samples examined. Extra-sharp, sharp, and medium Cheddar cheese samples contained average tyramine values of 0.27, 0.21, and 0.24 mg/g, respectively. Average tyramine contents were lower in mild and processed Cheddar (0.09 and 0.11 mg/g, respectively). The highest Cheddar cheese tyramine content was 0.7 mg/g. Tyramine was consistently found in all cheeses except in unripened soft cheese (Cottage). Histamine concentrations varied from nondetectable amounts to 2.6 mg/g in a Sap-Sago cheese sample. Twenty-four Cheddar cheese samples contained histamine with the highest amount being 1.3 mg/g. A domestic Blue cheese contained 2.3 mg/g. Tryptamine was uniformly low or completely absent in the Cheddar cheese samples. The highest tryptamine concentration (1.1 mg/g) was detected in a Blue cheese.

scholarly journals Identification and Quantification of an Adulterant in a Dietary Supplement Marketed for Sexual Enhancement

2018 ◽  
Vol 1 (4) ◽  
pp. 25-33 ◽  
Author(s):  
Flavia Redko ◽  
Sabrina Flor ◽  
Silvia Lucangioli ◽  
Jerónimo Ulloa ◽  
Rafael Ricco ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
High Performance ◽  
Spectroscopic Techniques ◽  
Easy Method ◽  
Isolation And Purification ◽  
Chromatography Analysis ◽  
Pharmaceutical Ingredients ◽  
Emerging Risk ◽  
The Mean ◽  
Layer Chromatography

In recent years, the consumption of dietary supplements (DS) has increased worldwide. In Argentina, approximately 14 million DS units were sold between 2015 and 2017. The adulteration of DS with active pharmaceutical ingredients or their analogues has been reported. This represents an alarming emerging risk to public health. The aim of this work was to detect the possible adulteration of a DS marketed in Argentina for the treatment of erectile dysfunction. Initially, thin layer chromatography analysis of the DS capsules content suggested the presence of a major compound. For the isolation and purification of this compound, an easy method consisted of a liquid-liquid extraction (water/CH2Cl2) followed by re-crystallisation from ethanol, is reported. Spectroscopic techniques such as mono- and bidimensional nuclear magnetic resonance, Fourier transform infrared spectroscopy and mass spectrometry allowed its identification as tadalafil. A rapid and reliable method was developed for the quantification of tadalafil in this DS by high performance liquid chromatography-mass spectrometry (HPLC-MS/MS). The mean content of tadalafil per capsule was 21.2 mg which represents a slightly higher value than that found in approved products in Argentina (5 or 20 mg per tablet). In addition, an undeclared alga was identified in the DS by microscopic techniques.

scholarly journals Evaluation of the Larvicidal Potential of the Leaf Extracts of Hyptis suaveolens Poit against Anopheles Mosquitoes

2018 ◽  
pp. 1-9
Author(s):  
Amaka, John I. ◽  
Attah, D. Daniel ◽  
Obisike, Victor U. ◽  
Benedict, Aboje G.
Keyword(s):  
Mosquito Control ◽  
Larval Instar ◽  
Test Organism ◽  
Phytochemical Screening ◽  
Leaf Extracts ◽  
Anopheles Mosquitoes ◽  
Lc50 Value ◽  
Hyptis Suaveolens ◽  
Test Organisms ◽  
Layer Chromatography

This study evaluated the larvicidal potential of the ethanolic and aqueous leaf extracts of Hyptis suaveolens Poit on the 4th larval instar of laboratory-reared Anopheles spp at varying concentrations of 0.1ml, 0.2ml, 0.3ml, 0.4ml and 0.5ml for specified periods of 24hrs, 48hrs and 72hrs. Qualitative phytochemical screening of the leaf extracts identified bioactive components like alkaloid, saponin, phenol, anthraquinone and flavonoid. The LC50 and LC90 values obtained indicate that the ethanolic leaf extracts of Hyptis suaveolens Poit had the greatest toxicity on the test organisms within 24hrs of exposure at median LC50 value of 0.485ml compared to the LC50 value of 0.625ml by its aqueous extract. The relative median potency estimates indicate that within 24 hrs, the ethanolic Hyptis suaveolens Poit was 0.161 times more potent on the test organism than aqueous Hyptis suaveolens Poit. The result of this research, therefore, underscores the efficacy of Hyptis suaveolens Poit as an eco-friendly alternative in Anopheles mosquito control. It is, therefore, recommended that quantitative phytochemical screening, application of column chromatography as well as thin layer chromatography be carried out on the extracts to isolate and purify toxic phytochemicals with larvicidal potentiality.

Bacillus Stearothermophilus Disc Assay: A Review

1995 ◽  
Vol 78 (6) ◽  
pp. 1408-1415
Author(s):  
Stanley E Katz ◽  
Marie Siewierski
Keyword(s):  
Bacillus Stearothermophilus ◽  
Assay Development ◽  
The Future ◽  
Development Data ◽  
History Of ◽  
Disc Assay

Abstract The literature on the Bacillus stearothermophilus disc assay was reviewed and evaluated. The history of the assay development; data on applicability, sensitivity, interferences, and cowside screening; potential for the future; and limitations are presented and discussed.

Determination of Antibiotics in Meat Using Bacillus stearothermophilus Spores

1981 ◽  
Vol 44 (3) ◽  
pp. 194-200 ◽  
Author(s):  
M. BIELECKA ◽  
J. D. BALDOCK ◽  
A. W. KOTULA
Keyword(s):  
Sample Size ◽  
Bacillus Stearothermophilus ◽  
Test Organism ◽  
Optimal Concentration ◽  
Antibiotic Residues ◽  
Plate Method ◽  
Assay Medium ◽  
Organism Growth ◽  
Ph Variations

Ten parameters affecting sensitivity, accuracy and simplicity of the diffusion plate method for determining antibiotic residues in meat were evaluated with spores of Bacillus stearothermophilus as the test organism. Eight antibiotics were studied and included penicillin, bacitracin, tetracycline, chlortetracycline, oxytetracycline, streptomycin, erythromycin and neomycin. Sensitivity of the method was most influenced by concentration of inoculum, quantity of assay medium on the plate and sample size. The optimal concentration of inoculum was established as 2 × 105 spores/ml of medium, quantity of the assay medium on plate/100 mm dia., as 6 ml and quantity of sample poured on disc/12.7 mm dia., as 100 μl. The pH of the assay medium was also important to both antibiotic potency and test organism growth. The activity of streptomycin and erythromycin was the most sensitive to pH variations.

Binding of 63Ni(II) to Ultrafiltrable Constituents of Rabbit Serum In Vivo and In Vitro

1975 ◽  
Vol 21 (4) ◽  
pp. 521-527 ◽  
Author(s):  
Noritake Asato ◽  
Maria van Soestbergen ◽  
F William Sunderman
Keyword(s):  
Rabbit Serum ◽  
Total Serum ◽  
In Vivo Experiments ◽  
The Mean ◽  
Layer Chromatography ◽  
In Vivo Administration ◽  
Mean Concentration

Abstract Binding of 63Ni(Il) to ultrafiltrable constituents of rabbit serum was studied (a) after in vitro incubation (2 h, 37 °C) of rabbit serum with 63NiCl2 (10-100 µmol/liter), and (b) at intervals (0.25-2 h) after in vivo administration of 63NiCl2 (40-160 µmol/kg body wt, i.v.). Serum ultrafiltrates were fractionated by thin-layer chromatography, and the separated compounds made visible by autoradiography and by ninhydrin staining. Several (≃5) ultrafiltrable 63Ni-complexes were demonstrable as distinct radiodense 63Ni-bands with chromatographic mobilities corresponding to those of ninhydrin-positive bands. Unbound 63Ni(II) was not detected in serum ultrafiltrates in either the in vitro or in vivo experiments. In sera (n = 10) incubated in vitro with 63Ni(II) (10 µmol/ liter), the mean percentage of ultrafiltrable 63Ni was 36% (range = 33-38) of total serum 63Ni. In contrast, in sera (n = 10) obtained 2 h after i.v. injection of 63Ni(II) (40 µmol/kg), the mean concentration of total serum 63Ni was 10.8 µmol/liter (range = 6-14), and the mean percentage of ultrafiltrable 63Ni was 15% (range = 9-21) of total serum 63Ni. The disparity between the percentages of ultrafiltrable 63Ni obtained in vitro and in vivo was obviated when the in vivo experiments were performed in rabbits bilaterally nephrectomized, with ligated common bile ducts. This investigation confirms the existence of several nickel receptors in serum ultrafiltrates and substantiates the role of ultrafiltrable complexes in the excretion of nickel.

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