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.

Interactive Effects of Spore Load and Temperature on Aflatoxin Production1

1990 ◽  
Vol 53 (3) ◽  
pp. 227-229 ◽  
Author(s):  
ANJANI KARUNARATNE ◽  
LLOYD B. BULLERMAN
Keyword(s):  
Mycelial Growth ◽  
Maximum Growth ◽  
Aflatoxin Production ◽  
Interactive Effects ◽  
Subsequent Growth ◽  
Visible Growth ◽  
Plate Counts ◽  
Extensive Growth ◽  
The Relationship ◽  
Spore Load

The relationship between initial spore load of an aflatoxigenic mold and subsequent growth and aflatoxin production were studied at 28 and 35°C. The initial spore loads ranges <101 to 107 spores/ml. As the spore level increased, visible growth appeared sooner and was more extensive. Growth, determined by viable plate counts, indicated that maximum growth in all the treatments reached 109 CFU/g, irrespective of the initial spore load. Mycelial growth and sporulation occurred faster at 35°C at all spore levels than at 28°C. At 28°C, unusually high amounts of aflatoxin Bl (380 ug/g) were produced when 103 spores were inoculated into 50 g rice, while the lower and the higher spore levels produced comparatively lower levels of aflatoxin. At 35°C the lowest spore level (<101 spores) produced the highest amount of aflatoxin B1 (62 μg/g). The higher spore levels at 35°C either did not result in any aflatoxin formation, or the amounts produced were negligible. At 35°C many fluorescing compounds other than aflatoxins were detected.

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.

Effects of Potassium Sorbate on Growth and Aflatoxin Production by Aspergillus parasiticus and Aspergillus flavus1

1983 ◽  
Vol 46 (11) ◽  
pp. 940-942 ◽  
Author(s):  
LLOYD B. BULLERMAN
Keyword(s):  
Aspergillus Flavus ◽  
Yeast Extract ◽  
Aflatoxin B1 ◽  
Spore Germination ◽  
Mycelial Growth ◽  
Aspergillus Parasiticus ◽  
Aflatoxin Production ◽  
Potassium Sorbate ◽  
Mycelial Mass ◽  
Yeast Extract Sucrose

Growth and aflatoxin production by selected strains of Aspergillus parasiticus and Aspergillus flavus in the presence of potassium sorbate at 12°C were studied. Potassium sorbate at 0.05, 0.10 and 0.15% delayed or prevented spore germination and initiation of growth, and slowed growth of these organisms in yeast-extract sucrose broth at 12°C. Increasing concentrations of sorbate caused more variation in the amount of total mycelial growth and generally resulted in a decrease in total mycelial mass. Potassium sorbate also greatly reduced or prevented production of aflatoxin B1 by A. parasiticus and A. flavus for up to 70 d at 12°C. At 0.10 and 0.15% of sorbate, aflatoxin production was essentially eliminated. A 0.05% sorbate, aflatoxin production was greatly decreased in A. flavus over the control, but only slightly decreased in A. parasiticus.

Aflatoxigenic Potential for Aspergilli on Sucrose Substrates

1980 ◽  
Vol 63 (3) ◽  
pp. 622-625
Author(s):  
Gerald C Llewellyn ◽  
Hudson C Jones ◽  
James E Gates ◽  
Thomas Eadie
Keyword(s):  
Carbon Source ◽  
Mycelial Growth ◽  
Aspergillus Parasiticus ◽  
Growth Period ◽  
Aflatoxin Production ◽  
Food And Drink

Abstract Sucrose concentrations of 3, 10, 20, and 30% in Czapek Dox broth served as the carbon source for growth, aflatoxin production, and sporulation for Aspergillus parasiticus NRRL 2999 and A flavus NRRL 3557, 5862, and 5013. All cultures produced mycelial growth and sporulated in all sucrose concentrations during the 12-day growth period. The area of mycelial mat coverage per hour increased directly with increased sugar concentrations. The 20 and 30% sucrose concentrations inhibited mycelial growth for 5862. The 30% sucrose cultures of 3557 and 5862 failed to produce detectable levels of aflatoxins. All other isolates produced B1 and G1 in an approximately 4:1 ratio in all sucrose concentrations. Only 2999 was a substantial producer of aflatoxin in all 4 sucrose cultures, ranging from 72 to 96 μg/mL medium. A. flavus 5013 produced the most toxin, 144 and 126 μg/mL medium in the 10 and 20% sucrose cultures, respectively. The 10 and 20% sucrose cultures were most conducive to aflatoxin production. Since these sucrose levels correspond closely to the levels in many food and drink products, especially home-made products, care and attention should be taken to keep them free of aflatoxigenic spores. Extensive mycelial growth and sporulation, even in aflatoxigenic strains, do not necessarily result in comparably high aflatoxin levels. Routine extraction and quantitation procedures for aflatoxin were applicable and provided satisfactory results.

EFFECT OF LOW DOSE GAMMA IRRADIATION ON GROWTH AND AFLATOXIN PRODUCTION BY ASPERGILLUS PARASITICUS1

1974 ◽  
Vol 37 (8) ◽  
pp. 430-434 ◽  
Author(s):  
L. B. Bullerman ◽  
T. E. Hartung
Keyword(s):  
Standard Deviation ◽  
Low Dose ◽  
Aspergillus Parasiticus ◽  
Aflatoxin Production ◽  
Toxin Production ◽  
The Other ◽  
Subsequent Growth ◽  
Irradiation Level ◽  
Yeast Extract Sucrose ◽  
Stimulation Of

Spores and growing vegetative mycelia of Aspergillus parasiticus strains NRRL 2999 and NRRL 3000 were irradiated at 100 and 200 Krad, and the effects on growth and aflatoxin production in yeast-extract sucrose (YES) broth were measured. Irradiation of growing mycelia reduced subsequent growth in YES broth by a greater amount than irradiation of spores. Irradiation of spores at 100 Krad resulted in more B1 and G1 production by strain NRRL 2999 than the non-irradiated control, however, strain NRRL 3000 produced less aflatoxins B1 and G1 after irradiation at 100 Krad than its non-irradiated control. Spores of both strains irradiated at 200 Krad produced less aflatoxins B1 and G1 than non-irradiated controls. Irradiation of growing vegetative mycelia of both strains at 100 and 200 Krad resulted in a definite decline in both aflatoxins B1 and G1 in subsequent cultures at each irradiation level. Apparent stimulation of production of both B1 and G1 occurred after irradiation of spores of strain NRRL 2999 at 100 Krad. However, the variation of the values as determined by the standard deviation was such that one would conclude that no differences existed among means. The apparent stimulation was slight and of much less magnitude than that which has been reported by other investigators using A. flavus. No stimulation of toxin production was observed with the other strain when grown from irradiated spores or with either strain when vegetative mycelia were irradiated.

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.

scholarly journals Antifungal Activity and Aflatoxin Degradation of Bifidobacterium Bifidum and Lactobacillus Fermentum Against Toxigenic Aspergillus Parasiticus

2016 ◽  
Vol 10 (1) ◽  
pp. 197-201 ◽  
Author(s):  
Roshanak Daie Ghazvini ◽  
Ebrahim Kouhsari ◽  
Ensieh Zibafar ◽  
Seyed Jamal Hashemi ◽  
Abolfazl Amini ◽  
...  
Keyword(s):  
Mycelial Growth ◽  
Aspergillus Parasiticus ◽  
Aflatoxin Production ◽  
Hplc Method ◽  
Bifidobacterium Bifidum ◽  
Lactobacillus Fermentum ◽  
Inhibition Rate ◽  
Plate Method ◽  
Mycelial Mass ◽  
Yeast Extract Sucrose

Food and feedstuff contamination with aflatoxins (AFTs) is a serious health problem for humans and animals, especially in developing countries. The present study evaluated antifungal activities of two lactic acid bacteria (LAB) against growth and aflatoxin production of toxigenic Aspergillus parasiticus. The mycelial growth inhibition rate of A. parasiticus PTCC 5286 was investigated in the presence of Bifidobacterium bifidum PTCC 1644 and Lactobacillus fermentum PTCC 1744 by the pour plate method. After seven days incubation in yeast extract sucrose broth at 30°C, the mycelial mass was weighed after drying. The inhibitory activity of LAB metabolites against aflatoxin production by A. parasiticus was evaluated using HPLC method. B. bifidum and L. fermentum significantly reduced aflatoxin production and growth rate of A. parasiticus in comparison with the controls (p≤0.05). LAB reduced total aflatoxins and B1, B2, G1 and G2 fractions by more than 99%. Moreover, LAB metabolites reduced the level of standard AFB1, B2, G1 and G2 from 88.8% to 99.8% (p≤0.05). Based on these findings, B. bifidum and L. fermentum are recommended as suitable biocontrol agents against the growth and aflatoxin production by aflatoxigenic Aspergillus species.

Growth, Sporulation and Aflatoxin Production by Aspergillus parasiticus on Strained Baby Foods

1980 ◽  
Vol 43 (6) ◽  
pp. 428-430 ◽  
Author(s):  
G. C. LLEWELLYN ◽  
N. E. DUCKHARDT ◽  
M. F. FISHER ◽  
T. EADIE ◽  
C. E. O'REAR
Keyword(s):  
Aspergillus Parasiticus ◽  
Total Yield ◽  
Aflatoxin Production ◽  
Toxin Production ◽  
Green Beans ◽  
Total Aflatoxin ◽  
Series Of Experiments ◽  
The Mean ◽  
Lower Temperature ◽  
Sporulation Rate

The potential for aflatoxin production by Aspergillus parasiticus on strained baby food was evaluated. Four puréed foods were inoculated with the mold and cultured at 15 and 26 C in two series of experiments. The aflatoxigenic mold produced mycelia and sporulated at both temperatures. The foods ranked in mean total yield of aflatoxin (μg/g of substrate) in the following order: peas > squash > green beans > pears. The ranking held consistent for both temperatures. Aflatoxins B1 and G1 were produced in higher percentages than B2 and G2 in each food at both temperatures. At 26 C, total aflatoxin produced ranged from 8 to 71 μg/g of substrate, and at 15 C, the mean for the four foods was from 3 to 50 μg/g of substrate. Temperature and substrate were the primary variables which contributed to sporulation rate, toxin production and toxin ratios. Peas and squash should be considered primary and highly supportive substrates for aflatoxin production if conditions should arise for spores to contaminate the products either during or after processing. Absolute prevention of aflatoxigenic spore contamination in these foods studied is essential. An occasional testing of these foods for aflatoxin seems warranted. A lower temperature during aflatoxin formation decreased the total toxin formed, but did not prohibit aflatoxin occurrence. A lower temperature also tended to divert the type of toxin produced from B1 to the less dangerous G1 and G2. Aflatoxin would appear to be a problem in these foods only under rare and unusual circumstances in relation to processing and consumer usage. If such aflatoxigenic spore contamination should occur, the levels produced would be significant.

Production of Aflatoxins B and G on Solid and Broth Culture Media

1977 ◽  
Vol 40 (12) ◽  
pp. 828-830 ◽  
Author(s):  
A. J. DELUCCA ◽  
R. Y. MAYNE ◽  
A. O. FRANZ ◽  
R. L. ORY
Keyword(s):  
Mycelial Growth ◽  
Aspergillus Parasiticus ◽  
Culture Media ◽  
Aflatoxin Production ◽  
The Other ◽  
Broth Culture ◽  
Solid Media

Mycelial growth and production of aflatoxins by Aspergillus parasiticus NRRL A-16,462, on whole peanuts, undelintered cottonseed, and shredded wheat was compared to growth and aflatoxin production on 10% broths of the same substrates. The greatest amount of toxins was produced on shredded wheat as a whole substrate. The least amount was produced in shredded wheat broth medium. Intermediate levels of toxin were produced on cottonseed in both types of media. More aflatoxin was produced on peanut broth than on whole peanuts. Mycelial growth on whole shredded wheat was greater than growth on the other solid media though it had the lowest amount of growth of the three broth media. Among whole substrates, growth on fuzzy cottonseed was least but mycelial growth on cottonseed broth was second of the three broth media. Growth on whole peanuts was as great as on shredded wheat; on peanut broth, it was the greatest of the three broth media. On whole substrates, the ratio of aflatoxins B:G produced was highest on shredded wheat and lowest on peanuts. In broth culture the B:G ratio was largest on the cottonseed and lowest on shredded wheat.

Growth and Aflatoxin Production by Aspergillus parasiticusNRRL 2999 as Affected by the Fungicide Iprodione1

1993 ◽  
Vol 56 (8) ◽  
pp. 718-721 ◽  
Author(s):  
AGUSTIN A. ARINO ◽  
LLOYD B. BULLERMAN
Keyword(s):  
Yeast Extract ◽  
Aspergillus Parasiticus ◽  
Aflatoxin Production ◽  
Toxin Production ◽  
Mold Growth ◽  
Yeast Extract Sucrose ◽  
Different Levels ◽  
Mycelial Development

Spores of Aspergillus parasiticus strain NRRL 2999 were inoculated into yeast extract sucrose broth containing different levels of iprodione (0, 1, 3, 5, 10, 15, and 20 (μg/ml) and incubated at 25°C for 4, 7, 10, 14, and 21 d. Iprodione inhibited mold growth and subsequent toxin production, beginning at the 5 μg/g level up to 7 d of incubation. Results showed that as the iprodione level increased, more time was required by the organism to initiate mycelial development. At any given time, the lower the iprodione level, the more dry mycelial weight and aflatoxin production (B1, B2, G1, and G2) were observed.

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