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.

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.

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.

scholarly journals Interaction Between Certain Moulds and Aflatoxin B1 Producer Aspergillus Flavus NRRL 3251

2007 ◽  
Vol 58 (4) ◽  
pp. 429-434 ◽  
Author(s):  
Zdenka Cvetnić ◽  
Stjepan Pepeljnjak
Keyword(s):  
Aspergillus Flavus ◽  
Aflatoxin B1 ◽  
Aflatoxin Production ◽  
Toxin Production ◽  
Airborne Fungi ◽  
Biotic Interaction ◽  
Detectable Amount ◽  
Single Culture ◽  
Aflatoxin B ◽  
Yeast Extract Sucrose

Interaction Between Certain Moulds and Aflatoxin B1ProducerAspergillus FlavusNRRL 3251The objective of this study was to evaluate biotic interaction between some mould species and active producer of aflatoxin B1Aspergillus flavusNRRL 3251, co-cultured in yeast-extract sucrose (YES) broth. Twenty-five mould strains ofAlternariaspp.,Cladosporiumspp.,Mucorspp.,A. flavusandA. niger, used as biocompetitive agents, were isolated from outdoor and indoor airborne fungi, scrapings of mouldy household walls, and from stored and post-harvest maize. Aflatoxin B1was extracted from mould biomasses with chloroform and detected using the multitoxin TLC method. The results confirm antagonistic interaction between all strains tested. WithAlternariaspp. andCladosporiumspp., aflatoxin B1production decreased 100 %, compared to detection in a single culture ofA. flavusNRRL 3251 (Cmean=18.7 μg mL-1). In mixed cultures withMucorspp., aflatoxinB1levels dropped to (5.6-9.3) μg mL-1, and the inhibition was from 50 % to 70 %. Four of five aflatoxin non-producing strains ofA. flavusinterfered with aflatoxin production in mixed culture, and reduced AFB1productivity by 100 %. One strain showed a lower efficacy in inhibiting AFB1production (80 %) with a detectable amount of AFB13.7 μg mL-1when compared to control. A decrease in toxin production was also observed in dual cultivation withA. nigerstrains. It resulted in 100 % reduction in three strains), 90 % reduction in one strain (Cmean=1.9 μg mL-1) and 80 % reduction in one strain (Cmean=3.7 μg mL-1) inhibition.

Extracts of Agave americana inhibit aflatoxin production in Aspergillus parasiticus

2011 ◽  
Vol 4 (1) ◽  
pp. 37-42 ◽  
Author(s):  
A. Rosas-Taraco ◽  
E. Sanchez ◽  
S. García ◽  
N. Heredia ◽  
D. Bhatnagar
Keyword(s):  
Aspergillus Parasiticus ◽  
Public Awareness ◽  
Aflatoxin Production ◽  
Aflatoxin Contamination ◽  
Aqueous Extracts ◽  
Total Aflatoxin ◽  
Toxigenic Fungi ◽  
Agave Americana ◽  
Acid Accumulation ◽  
Norsolorinic Acid

Toxigenic fungi invade crops prior to harvest as well as during storage and produce harmful, even carcinogenic toxins such as aflatoxins. Since consumers demand safe commodities, and due to enhanced public awareness of the dangers of many synthetic fungicides, the importance of investigating alternative, natural products to control these toxigenic fungi is clear. This study investigated the effect of aqueous extracts of Agave americana on growth, conidia and aflatoxin production. Aspergillus parasiticus strains SRRC 148, SRRC 143 (Su-1), and A. parasiticus SRRC 162, a mutant (nor-) that accumulates norsolorinic acid (NOR, an orange-coloured intermediate of the aflatoxin pathway), were first inoculated into Adye and Mateles liquid medium, then plant extracts were added, and incubated at 28 °C for 7 days. Aflatoxin and norsolorinic acid were assayed by HPLC and spectrophotometry, respectively. While the extract of A. americana stimulated growth of the studied fungi, conidiogenesis, norsolorinic acid accumulation (in the nor- mutant), and aflatoxin production were significantly affected. The reduction was produced by the extracts at concentrations higher than 5-10 mg/ml, where all types of total aflatoxin analysed (aflatoxins B1, B2, G1 and G2) were reduced from 64% to >99% in the whole culture, and a reduction of 75% of norsolorinic acid. The results of the present work indicate that extracts of A. americana may be promising safe alternatives to harmful fungicides for controlling aflatoxin contamination.

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.

scholarly journals Detection and Quantitation of Aflatoxin for the Diagnosis of Aspergillus flavus

2015 ◽  
Vol 3 (1) ◽  
pp. 6-9 ◽  
Author(s):  
Geeta Rajbhandari Shrestha ◽  
Amin Udhin Mridha
Keyword(s):  
Aspergillus Flavus ◽  
Yeast Extract ◽  
Aflatoxin B1 ◽  
Sucrose Concentration ◽  
Synthetic Medium ◽  
Enzyme Linked Immunosorbent Assay ◽  
P Value ◽  
Detection And Diagnosis ◽  
Immunological Assays ◽  
Yeast Extract Sucrose

Aflatoxins are the potent mycotoxins produced by Aspergillus flavus, which is hepatotoxic causing hepatocellular carcinoma. A. flavus produces sufficient amount of Aflatoxin B1 under favourable environments. Inhalation of spores and use of Aflatoxin B1, contaminated food by Aspergillus spp., could transfuse the toxins in the blood streams. The presence of these toxins in body fluid can be detected by immunological assays and which provides an effective technique for the diagnosis of the disease caused by A. flavus. Aflatoxins producing strain of A. flavus were screened in Aflatoxin Producing Medium. Production of Aflatoxin B1 by A. flavus was studied in different parameters such as incubation periods, temperatures, pH variations, sucrose concentration in Yeast Extract Sucrose medium and different natural media such as par-boiled rice, corn and groundnuts. The detection of toxins was done by TLC using silica gel (Merk) coated plates and confirmative test was done by Association of Official Analytical Chemists (AOAC) method. Presence and quantization was done by Enzyme Linked Immunosorbent Assay (ELISA) technique. Highest amount of Aflatoxin B1 was reported 68.56 ng/ml by ELISA in synthetic medium (Yeast Extract Sucrose) with 2% sucrose, pH 5.5, on 14th days of incubation, at 28±1°C (p-value 0.05). Similarly, highest amount was recorded in groundnuts (121.20ng/g) by ELISA and (500ng/kg) by TLC methods. ELISA is one of the most efficient methods used for detection and diagnosis of human diseases cause due to exposure of Aflatoxin B1 and A. flavus.Nepal Journal of Biotechnology. Dec. 2015 Vol. 3, No. 1: 6-9

Growth and Aflatoxin Production by Aspergillus parasiticus NRRL 2999 in the Presence of Acetic or Propionic Acid and at Different Initial pH Values

1987 ◽  
Vol 50 (11) ◽  
pp. 909-914 ◽  
Author(s):  
GULAM RUSUL ◽  
FATHY E. EL-GAZZAR ◽  
ELMER H. MARTH
Keyword(s):  
Acetic Acid ◽  
Propionic Acid ◽  
Aflatoxin B1 ◽  
Maximum Concentration ◽  
Aspergillus Parasiticus ◽  
Dry Weight ◽  
Aflatoxin Production ◽  
Lag Phase ◽  
Significant Difference ◽  
Initial Ph

Experiments were done to determine effects of different concentrations of acetic or propionic acid in a glucose-yeast extract-salts medium with an initial pH value of 4,5 or 5.5 on growth and aflatoxin production by Aspergillus parasiticus NRRL 2999. Amounts of aflatoxin were measured with reversed-phase high-performance liquid chromatography. The maximum concentration of acetic or propionic acid that permitted growth at an initial pH of 5.5 was 1% after 7 d of incubation and 0.25% after 3 d of incubation, respectively. When the initial pH of the medium was 4.5, the maximum concentration of acetic or propionic acid that permitted growth was 0.25 or 0.1%, respectively. There was no significant difference (p>0.05) in amount of mycelial (dry weight) produced by cultures in the presence of 0.0, 0.25, 0.50 or 0.75% acetic acid. Amounts of aflatoxin B1 and G1 produced decreased with an increasing concentration of acetic acid. Increasing concentrations of propionic acid caused a decrease in the amount of mycelial dry weight and aflatoxin produced by cultures growing in the medium with an initial pH of 5.5. At an initial pH of 4.5 mycelial growth was slow and at 3 d of incubation amounts of aflatoxin B1 and G1 produced were reduced as concentrations of acetic acid increased. This also was true for propionic acid in the medium with an initial pH of 4.5. Cultures with an extended lag phase in the presence of acetic or propionic acid overcame this and then produced large amounts of aflatoxin B1 and G1 at 7 and 10 d of incubation.

Ultrastructure of a caffeine-resistant mutant of Aspergillus parasiticus during aflatoxin production

1987 ◽  
Vol 45 ◽  
pp. 978-979
Author(s):  
S. B. Jones ◽  
T. O. Dobson ◽  
H. G. Stahl ◽  
R. L. Buchanan
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Aspergillus Parasiticus ◽  
Resistant Mutant ◽  
Aflatoxin Production ◽  
Mineral Salts ◽  
Ultrastructure Study ◽  
Fungal Pellets ◽  
Aflatoxin Accumulation

Caffeine (1,3,7-trimethylxanthine) inhibits growth and aflatoxin synthesis in A. parasiticus. A caffeine-resistant mutant (BCR1) of A. parasiticus NRRL 2999 was isolated in which sporulation and aflatoxin production occurred only in the presence of caffeine. Further, when cultured in glucose-mineral salts (GMS), BCR1 required amino acids in addition to caffeine in order to produce aflatoxin. A system for ultrastructure study was thus available in which aflatoxin synthesis was controlled by supplementation with amino acids. Experiments were conducted to identify morphology that could be correlated with aflatoxin production in the mutant.Cultures were conidia-initiated in GMS at 28C with agitation, with 6% peptone as amino acid source. Caffeine at 4 mg/ml permitted full growth and stimulated maximal aflatoxin accumulation. Fungal pellets were retrieved at 4 days and portions of the periphery were fixed in 3% glutaraldehyde in 80 mM Na-cacodylate, pH 7.0, for 3 hr.

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.

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