Aspergillus parasiticus Growth and Aflatoxin Synthesis on Florunner Peanuts Grown in Gypsum-Supplemented Soil

1993 ◽  
Vol 56 (7) ◽  
pp. 593-594 ◽  
Author(s):  
CINDY L. C. REDING ◽  
MARK A. HARRISON ◽  
CRAIG K. KVIEN
Keyword(s):  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Fungal Biomass ◽  
Aspergillus Parasiticus ◽  
Calcium Supplementation ◽  
Fungal Growth ◽  
Growing Season ◽  
Aflatoxin Production ◽  
Layer Chromatography

Five levels of gypsum supplementation (0, 550, 1100, 2200, and 4400 kg ha−1) were applied to peanut fields 35 d after planting. After the growing season, peanuts were harvested, ground, and inoculated with 1 × 107 Aspergillus parasiticus (NRRL 5139) conidia. After 14 d at 25°C, aflatoxin was extracted and quantified by thin-layer chromatography. Fungal growth was assayed using a modified chitin assay. Peanuts from gypsum-supplemented fields at each level of supplementation supported significantly less aflatoxin production when compared to control peanuts (no calcium supplementation). Results from the chitin assay showed a decrease in fungal biomass which correlated with the decreased aflatoxin synthesis.

EXPERIMENTAL PRODUCTION OF AFLATOXIN ON BRICK CHEESE1

1972 ◽  
Vol 35 (10) ◽  
pp. 585-587 ◽  
Author(s):  
C. N. Shih ◽  
E. H. Marth
Keyword(s):  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Aspergillus Flavus ◽  
Aspergillus Parasiticus ◽  
Solvent System ◽  
Experimental Production ◽  
Mold Growth ◽  
Layer Chromatography ◽  
Plastic Containers ◽  
Chloroform Methanol

Brick cheese was placed in plastic containers and all surfaces except the top were sealed with wax. The top was inoculated with Aspergillus flavus or Aspergillus parasiticus and cheese was incubated in a humid chamber at 7.2, 12.8, and 23.9 C for up to 14 weeks after mold growth was evident. After incubation each cheese was cut horizontally into four layers, each approximately 1 cm thick. Each layer of cheese was extracted with a monophasic-biphasic solvent system (chloroform, methanol, and water). The extract was purified, concentrated, and aflatoxins were measured by thin-layer chromatography and fluorometry. No aflatoxins were produced by either mold at 7.2 C. At 12.8 C, A. parastticus developed aflatoxins B1 and G1 after 1 week of incubation. Aflatoxin produced by this mold persisted through 4 weeks of storage and then was not detectable. Aspergillus flavus did not form aflatoxin at 12.8 C. Both molds produced aflatoxin on cheese at 23.9 C; A. parasiticus did so after 1 week and A. flavus after 14 weeks. In some instances, aflatoxin was found in cheese 4 cm from the surface. It is reasonable to assume that cheese will not become contaminated with aflatoxin if the food is held at or below 7 C.

Simplified Method for Microscale Production and Quantification of Aflatoxin in Broth1

1984 ◽  
Vol 47 (7) ◽  
pp. 526-529 ◽  
Author(s):  
WEI-YUN J. TSAI ◽  
JIMMY D. LAMBERT ◽  
LLOYD B. BULLERMAN
Keyword(s):  
Solvent Extraction ◽  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Frozen Storage ◽  
Aflatoxin Production ◽  
Production Studies ◽  
Simplified Method ◽  
Tlc Plates ◽  
Layer Chromatography ◽  
Yeast Extract Sucrose

A simplified method for aflatoxin production studies is described. The mold was cultured in 4-dram (15 ml) vials containing 5 ml of yeast extract sucrose broth, and aflatoxin levels were determined by direct spotting of the broth on thin layer chromatography (TLC) plates and quantitating by spectrodensitometry. Equivalent levels of aflatoxins were produced in vials as compared to flasks. When compared to conventional TLC after solvent extraction, direct spotting was rapid, economical and statistically equivalent. Heating broth cultures (121°C, 15 s) before TLC improved the release of aflatoxin from mycelial mats. Aflatoxins were unstable in YES broth during 3 months of frozen storage.

Susceptibility of Strawberries, Blackberries, and Cherries to Aspergillus Mold Growth and Aflatoxin Production

1982 ◽  
Vol 65 (3) ◽  
pp. 659-664 ◽  
Author(s):  
Gerald C Llewellyn ◽  
Thomas Eadie ◽  
William V Dashek
Keyword(s):  
Acetic Acid ◽  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Mycelial Growth ◽  
Methylene Chloride ◽  
Aflatoxin Production ◽  
Solvent System ◽  
Mold Growth ◽  
Tlc Plates ◽  
Layer Chromatography

Abstract The susceptibility of blackberries, cherries, and strawberries to Aspergillus growth and aflatoxin production has been examined. Three aflatoxigenic isolates of Aspergillus, A. flavus ATCC 15548 and NRRL 3251 as well as A. parasiticus NRRL 2999, were cultured on homogenates of the fruits for 14 days at 28 ± 2°C. Percent mycelial growth and spore infestation were determined each day with a calibrated grid. At day 14 each culture was frozen at –5°C until aflatoxins were extracted with methylene chloride and water. Aflatoxins were separated by thin layer chromatography (TLC) with benzene-methanol-acetic acid (90 + 5 + 5). This extraction and solvent system provided satisfactory separations of the aflatoxins and was free of background interference on the TLC plates. Although all fruits served as substrates for both Aspergillus growth and aflatoxin production, cherries appeared to be a more favorable substrate than did blackberries, and the latter was more favorable than strawberries. Whereas A. flavus produced both B1 and G1 on all substrates, it yielded B2 and G2 only on cherries. Although A. parasiticus NRRL 2999 synthesized B1, B2, G1, and G2 on both blackberries and cherries, no aflatoxins were detected on strawberries. In contrast, A. flavus NRRL 3251 failed to produce detectable levels of aflatoxin on any substrate. All substrates supported both mycelial growth and subsequent sporulation with cherries > blackberries > strawberries.

Xanthotoxin and Bergapten in Spring Parsley

Weed Science ◽  
1970 ◽  
Vol 18 (4) ◽  
pp. 479-480 ◽  
Author(s):  
M. Coburn Williams
Keyword(s):  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Infrared Spectra ◽  
Growing Season ◽  
Melting Points ◽  
Plant Samples ◽  
Rf Values ◽  
Layer Chromatography

Two phototoxic compounds, xanthotoxin (8-methoxysporalen) and bergapten (5-methoxypsoralen), were isolated from spring parsley [Cymopterus watsonii(Coult. & Rose) Jones] by thin-layer chromatography, and identified by comparison of Rf values, infrared spectra, and melting points, with pure samples. The concentration of xanthotoxin was two to four times that of bergapten in plant samples collected during the 2-month growing season. Seeds contained xanthotoxin and bergapten in equal concentrations.

PRODUCTION OF AFLATOXIN IN PRE-PACKAGED LUNCHEON MEAT AND CHEESE AT REFRIGERATOR TEMPERATURES1

1971 ◽  
Vol 34 (7) ◽  
pp. 349-351 ◽  
Author(s):  
L. S. Oldham ◽  
F. W. Oehme ◽  
D. C. Kelley
Keyword(s):  
Public Health ◽  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Aspergillus Flavus ◽  
Aflatoxin Production ◽  
Aflatoxin Concentration ◽  
Luncheon Meat ◽  
The Common ◽  
Meat Samples ◽  
Layer Chromatography

Information is lacking on the ability of the common mold contaminant, Aspergillus flavus, to grow and produce aflatoxin in perishable foods at normal refrigerator temperatures. Because of public health interests we investigated the possibility of certain perishable foods contaminated with the mold developing an aflatoxin concentration under conditions of refrigeration. Cheddar cheese and luncheon-meat samples were inoculated with A. flavus ATCC 15517 and were refrigerated for 12 days at 4.4 or 7.2 C or incubated at 25 C for 12 days, Uninoculated cheese and meat samples were handled in the same manner. All samples were quantitatively analyzed by thin-layer chromatography for presence of aflatoxin. All samples; except those inoculated and incubated at 25 C, were negative for aflatoxin production. This indicated the mold would, not produce detectable aflatoxin in the tested foods when kept at normal refrigeration temperatures for 12 days.

Antimycotic and Antiaflatoxigenic Activity of Oregano (Origanum vulgare, L.) and Thyme (Thymus vulgaris, L.)

1990 ◽  
Vol 53 (8) ◽  
pp. 697-700 ◽  
Author(s):  
J. SALMERON ◽  
R. JORDANO ◽  
R. POZO
Keyword(s):  
Ethylene Oxide ◽  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Aspergillus Flavus ◽  
Aspergillus Parasiticus ◽  
Dry Weight ◽  
Thymus Vulgaris ◽  
Origanum Vulgare ◽  
Layer Chromatography ◽  
Yeast Extract Sucrose

Oregano and thyme, ground and sterilized with ethylene oxide, were added to culture broths YES (yeast extract sucrose) so that the final concentrations of the herbs were 0, 0.25, 0.5, 1, 2, and 4%. The broths were inoculated with a spore suspension of Aspergillus parasiticus and Aspergillus flavus and incubated at 25°C for 4, 7, 10, 14, and 21 d. Then, the growth of the cultures as mycelium dry weight and the production of aflatoxins (B1 and G1) by fluorimetry, after separation by thin layer chromatography (TLC), were determined. Although oregano and thyme stimulate the growth of both strains of molds, at the same time they act as antiaflatoxigenics.

Application of High-Speed Liquid Chromatography to the Analysis of Aflatoxins

1973 ◽  
Vol 56 (4) ◽  
pp. 827-830 ◽  
Author(s):  
James N Seiber ◽  
Dennis P H Hsieh
Keyword(s):  
Liquid Chromatography ◽  
Quantitative Analysis ◽  
Thin Layer ◽  
Thin Layer Chromatography ◽  
Porous Layer ◽  
High Speed ◽  
Aspergillus Parasiticus ◽  
Coefficients Of Variation ◽  
Silica Adsorbent ◽  
Layer Chromatography

Abstract Partial resolution of aflatoxins B1, B2, G1, G2, and P1 was achieved by high-speed liquid chromatography (HSLC) on a porous layer silica adsorbent, using chloroform-isooctane as the eluting solvent and a 254 nm UV monitor for detection. The resolution was somewhat less than, although comparable with, that obtained by thin layer chromatography, using Adsorbosil-1 adsorbent and fluorodensitometric detection. The HSLC response to B1 and G1 was linear in the 400–3000 ng range, allowing application of the technique to the quantitative analysis of B1 and G1 in crude extracts of Aspergillus parasiticus cultures. The coefficients of variation (precision) were 4.2% for B1 and 23.2% for G1 in a series of 4 replicate injections. The advantages and limitations of the technique for quantitative analysis and isolation are compared with those of more conventional chromatographic methods.

Aspergillus parasiticus NRRL 2667 Growth and Aflatoxin Synthesis as Affected by Calcium Content and Initial Spore Load in Single Peanuts

1994 ◽  
Vol 57 (5) ◽  
pp. 415-418 ◽  
Author(s):  
MA. ROCELLE S. CLAVERO ◽  
MARK A. HARRISON ◽  
YEN-CON HUNG
Keyword(s):  
Mycelial Growth ◽  
Aspergillus Parasiticus ◽  
Calcium Supplementation ◽  
Calcium Content ◽  
Maximum Growth ◽  
Aflatoxin Production ◽  
Toxin Production ◽  
Plate Counts ◽  
Layer Chromatography ◽  
Spore Load

Mycelial growth of Aspergillus parasiticus NRRL 2667 and aflatoxin production on Florunner peanuts grown under different calcium supplementation levels (CSL) (550, 1,100, 2,200 and 4,400 kg gypsum/ha) with initial spore loads of 102, 104 and 106 spores/g were investigated. Growth at 25°C for 0, 4, 7 and 14 days was determined by viable plate counts on Aspergillus flavus/parasiticus agar (AFPA) medium. Irrespective of the initial spore load, maximum growth of 108 to 109 CFU/g was attained after 14 days except for the 4,400 kg/ha Ca-supplemented nuts on which the maximum populations were one log less. Aflatoxins B1 and G1 concentrations measured by thin layer chromatography (TLC) ranged from 0–3460 (μg/g and 0–3740 (μg/g, respectively. Toxin production was highest in single peanuts with CSL of 2,200 kg/ha. A reduction of 50% or higher was observed as CSL was increased to 4,400 kg/ha.

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