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.

Effects of Nutrients and Inhibitors in Olives on Aflatoxigenic Molds1

1987 ◽  
Vol 50 (11) ◽  
pp. 959-963 ◽  
Author(s):  
ABDELMAJID MAHJOUB ◽  
LLOYD B. BULLERMAN
Keyword(s):  
Amino Acids ◽  
Yeast Extract ◽  
Aflatoxin B1 ◽  
Aspergillus Parasiticus ◽  
Aflatoxin Production ◽  
Toxin Production ◽  
Aqueous Extracts ◽  
Poor Growth ◽  
Extensive Growth ◽  
Yeast Extract Sucrose

Growth and aflatoxin production by Aspergillus parasiticus NRRL 2999 and Aspergillus flavus NRRL 6555 were studied on fresh olives, fresh olives supplemented with nutrients, and fresh olives treated with heat, lye, and freezing temperatures. Studies were also done on yeast extract sucrose agar (YESA) either mixed with chopped fresh olives or made with aqueous extracts of fresh and treated olives. Samples were incubated at 25°C for 7 d. Olive paste supplemented with zinc and sucrose supported little growth and no aflatoxin B1 production. Amino acids, yeast extract, and a combination of zinc, carbohydrate, and amino acids exhibited extensive growth and moderate amounts of aflatoxin. Fresh and frozen olive pastes supported poor growth and no aflatoxin production. Heat- and lye-treated olives supported extensive growth and little aflatoxin production. Heavy growth and moderate amounts of aflatoxin B1 were supported by YES A mixed with olive pastes. YES A made with aqueous extracts of olives supported extensive growth and moderate toxin production, except on YES A made with extract from frozen olives which exhibited poor growth and low toxin amounts. A. flavus grew similarly to A. parasiticus but was unable to produce any aflatoxin except on heat- and lye-treated olives, where traces were detected. Olives are a poor substrate for mold development and may contain inhibiting substances against growth and aflatoxin production.

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.

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.

Aflatoxin Production in Black Currant, Blueberry and Strawberry Jams

1978 ◽  
Vol 41 (5) ◽  
pp. 344-347 ◽  
Author(s):  
O. PENSALA ◽  
A. NISKANEN ◽  
S. LINDROTH
Keyword(s):  
Yeast Extract ◽  
Raw Materials ◽  
Fungal Growth ◽  
Dry Weight ◽  
Aflatoxin Production ◽  
Fungal Mycelium ◽  
Black Currant ◽  
Initial Ph ◽  
Different Temperatures ◽  
Yeast Extract Sucrose

Unsweetened and sweetened (20 and 44% sucrose) black currant, blueberry and strawberry jams with spores of Aspergillus parasiticus NRRL 2999 were incubated at different temperatures and atmospheres for 0.5, 1, 2, and 6 months. Hyphal dry weight, pH of medium and aflatoxin production were examined. Also, the aflatoxin distribution between mold and jam layers was examined in jam with uncontrolled and controlled pH (initial pH 3.1–3.6 and 5.6 respectively) and in 20% yeast extract sucrose broth (initial pH 5.6) after 2 weeks of incubation. Aflatoxin was observed in black currant and strawberry jams stored at 22 and 30 C, but not in blueberry jam. Addition of sugar prevented production of aflatoxin in detectable amounts, although it enhanced fungal growth. Storage at 4 C resulted in a marked reduction in fungal growth. The high CO2 atmosphere prevented production of aflatoxin in detectable amounts in black currant and blueberry jams but not in strawberry jam. Raising the initial pH of the stored jam caused an increase in aflatoxin synthesis, although the amount of fungal mycelium, in contrast was reduced. Aflatoxin synthesis as a function of fungal growth was significantly weaker in the jams than in the yeast extract sucrose broth. The results imply that the jam raw materials, particularly blueberry, contain substances inhibiting production of atlatoxins. Alternatively, it is also possible that the jam materials contain only small amounts of nutrients necessary for synthesis of aflatoxin.

Growth and Synthesis of Aflatoxin by Aspergillus parasiticus in the Presence of Sorbic Acid

1981 ◽  
Vol 44 (10) ◽  
pp. 736-741 ◽  
Author(s):  
AHMED E. YOUSEF ◽  
ELMER H. MARTH
Keyword(s):  
Incubation Period ◽  
Aspergillus Parasiticus ◽  
Sorbic Acid ◽  
Aflatoxin Production ◽  
Potassium Sorbate ◽  
Mold Growth ◽  
Early Stages ◽  
Cumulative Data ◽  
The Media ◽  
Growth Ph

Two media [basal (M1) and enriched (M2)] containing potassium sorbate (0–300 ppm as sorbic acid) were inoculated with spores (104 – 106/flask) of Aspergillus parasiticus and incubated for 5 days at 28 C. The greater the amount of sorbate added, the higher was the pH of the media after incubation and the smaller was the yield of mold mycelium. Intermediate amounts of sorbate sometimes resulted in greater accumulation of aflatoxin than when media were free of sorbate. Sorbate more effectively inhibited mold growth and aflatoxin production in medium M2 than M1 and when the small rather than the large inoculum was used. A second trial was done with 106 or 105 spores/flask of M2 (ca. 27 ml) and 105 spores/flask of M2 (ca. 27 ml) containing sorbate (200 ppm of sorbic acid). Cumulative data for mold growth. pH and content of aflatoxin in the medium showed that relative effects of different treatments changed during the incubation period. An index to measure the capacity of molds to synthesize aflatoxins was developed. Application of the index indicates that sorbate delayed mold growth but did not inhibit biosynthesis of aflatoxin. The ability to synthesize aflatoxin was greatest in the early stages of mold growth and then decreased linearly as mold growth progressed.

Mycoflora and Aflatoxin-Producing Strains in Animal Mixed Feeds

1994 ◽  
Vol 57 (3) ◽  
pp. 256-258 ◽  
Author(s):  
M. L. ABARCA ◽  
M. R. BRAGULAT ◽  
G. CASTELLÁ ◽  
F. J. CABAÑES
Keyword(s):  
Aspergillus Flavus ◽  
Yeast Extract ◽  
Penicillium Chrysogenum ◽  
Fusarium Moniliforme ◽  
Dominant Species ◽  
Aflatoxin Production ◽  
Fungal Species ◽  
Sucrose Medium ◽  
Mixed Feeds ◽  
Yeast Extract Sucrose

The mycoflora of 69 samples of animal mixed feeds were studied. Fungal counts ranged from 102 to 108 CFU/g, the lowest counts corresponding to the samples of rabbit feeds. Seventy-one fungal species belonging to 26 genera were identified. The pre- dominant species were Aspergillus flavus, Fusarium moniliforme, and Penicillium chrysogenum. Thirty-six strains of A. flavus and one strain of A. parasiticus were screened for aflatoxin production in yeast extract-sucrose medium. The final pH, weight of mycelium, and production of aflatoxins were determined after 14 days of incubation. Five strains (13.5%) were aflatoxigenic. No statistical differences were observed in mycelial dry weights and final pH between aflatoxin-producing strains and nonaflatoxigenic strains.

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.

Aflatoxin Production in a Meat Mix Model System in the Presence of Pediococcus and Lactobacillus

1992 ◽  
Vol 55 (8) ◽  
pp. 583-587 ◽  
Author(s):  
ROSA H. LUCHESE ◽  
JOSÉ F. P. MARTINS ◽  
WILKIE F. HARRIGAN
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Aspergillus Parasiticus ◽  
Aflatoxin Production ◽  
Model System ◽  
Medium Composition ◽  
Mold Growth ◽  
Processing Conditions ◽  
Irradiated Meat ◽  
Incubation Temperatures

The effect on aflatoxin production by Aspergillus parasiticus of eight individual strains of Pediococcus and Lactobacillus was determined. The study was conducted in an axenic cultural system in which irradiated meat was employed in the formulation of a meat medium. The medium composition and incubation temperatures were simulations of Brazilian salami processing conditions. All single cultures of A. parasiticus supported aflatoxin production. More aflatoxin was produced in samples treated by the addition of lactic acid than in nontreated ones. Aflatoxin was not detected when A. parasiticus was grown with lactic acid bacteria, although visible mold growth was observed in all such cultures.

Antifungal Activity of Chitosan and Its Preservative Effect on Low-Sugar Candied Kumquat

1994 ◽  
Vol 57 (2) ◽  
pp. 136-140 ◽  
Author(s):  
SHAO W. FANG ◽  
CHIN F. LI ◽  
DANIEL Y. C. SHIH
Keyword(s):  
Shelf Life ◽  
Aspergillus Parasiticus ◽  
Aflatoxin Production ◽  
Inhibitory Effect ◽  
Life Extension ◽  
Potassium Sorbate ◽  
Mold Growth ◽  
Chitosan Concentration ◽  
Significant Difference ◽  
Order Polynomial

The inhibitory effect of chitosan, a deacetylated form of chitin, on the growth of Aspergillus niger and the aflatoxin production of Aspergillus parasiticus was evaluated. The inhibitory effect of chitosan against A. niger was increased as the chitosan concentration was increased from 0.1 to 5.0 mg/ml (pH 5.4). At concentrations of 4.0 or 5.0 mg/ml, chitosan was less effective than potassium sorbate in inhibiting the growth of A. niger. The greatest inhibitory effect of chitosan against A. parasiticus was found at 3.0–5.0 mg/ml. In addition, chitosan could completely prevent aflatoxin production by A. parasiticus at the concentration of 4.0–5.0 mg/ml. Chitosan (2.0 and 5.0 mg/ml) induced considerable leakage of UV-absorbing and proteinaceous material of A. niger at pH 4.8. Using the response surface methodology, a second order polynomial model was derived and used to predict the number of days to obtain visible mold growth under various combinations of chitosan concentrations and °Brix in candied kumquat. The results showed that there was no significant difference in shelf-life extension of candied kumquat at chitosan concentration of 3.5–6.5 mg/ml. However, °Brix had a significant effect on shelf life. Candied kumquat with 6.0 mg/ml chitosan concentration and 61.9° Brix had a predicted mold-free shelf life of 65.3 d.

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.

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