Aflatoxin Production by Aspergillus parasiticus and Its Stability During the Manufacture of Korean Soy Paste (Doenjang) and Soy Sauce (Kanjang) by Traditional Method

1988 ◽  
Vol 51 (12) ◽  
pp. 938-944 ◽  
Author(s):  
KUN-YOUNG PARK ◽  
KYU-BOK LEE ◽  
LLOYD B. BULLERMAN
Keyword(s):  
Bacillus Subtilis ◽  
Mixed Culture ◽  
Traditional Method ◽  
Degradation Rate ◽  
Aspergillus Parasiticus ◽  
Aflatoxin Production ◽  
Toxin Production ◽  
Soy Sauce ◽  
Natural Conditions ◽  
Soybean Cake

Aflatoxin (AF) production and its stability on meju (crushed Korean soybean cake) by a pure culture of Aspergillus parasiticus and a mixed culture of A. parasiticus. A. oryzae and Bacillus subtilis (fermentation 1) during the manufacture by traditional methods of Korean soy paste (doenjang) and soy sauce (kanjang) were studied. There was a difference in the amount of aflatoxin production on different varieties of soybeans, but the pattern of toxin production was similar. During fermentation, more total aflatoxins were produced under the mixed culture condition. Aflatoxin G1 (AFG1) production was highly stimulated though it degraded quickly, whereas aflatoxin B1 (AFB1) synthesis was low. The exposure of the meju to sunlight during fermentation had no effect in reducing aflatoxin synthesis. When the meju fermented under natural conditions (fermentation 2) with a contamination by A. parasiticus, high levels of aflatoxins were still produced. After a month of ripening of the fermented meju with charcoal in brine, more AFG1 than AFB1 was degraded in both the pure and mixed culture samples (degradation %; B1:2–69%, G1:31–84%). When the meju was ripened in water, most of the aflatoxins were degraded (B1:95–99%, G1:100%) in a month, accompanied by a significant increase in pH (p<0.05). A greater amount of aflatoxins (96–100%) was detected in the meju when it was ripened in brine, however, lower amounts (25–85%) of aflatoxins remained in meju ripened in water. During three months of ripening in brine, 83–98% of AFB1 and 98–100% of AFG1 were degraded in fermentation 1, but the degradation rate was slower (B1 :63%, G1:98%) following fermentation 2. The total levels of aflatoxins remaining were significantly (p<0.05) reduced when charcoal was added to the mixture.

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.

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.

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.

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.

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.

Production of Aflatoxin in Cocoa Beans

1979 ◽  
Vol 62 (5) ◽  
pp. 1076-1079 ◽  
Author(s):  
Lawrence M Lenovich ◽  
W Jeffrey Hurst
Keyword(s):  
High Pressure ◽  
Liquid Chromatography ◽  
Ivory Coast ◽  
Aspergillus Parasiticus ◽  
Aflatoxin Production ◽  
Growth Conditions ◽  
Aflatoxin Contamination ◽  
Cocoa Beans ◽  
Total Aflatoxin ◽  
Substrate Variation

Abstract Aflatoxin was produced in both non-autoclaved and autoclaved Ivory Coast cocoa beans inoculated with Aspergillus parasiticus NRRL 2999 under optimum laboratory growth conditions. Total aflatoxin levels ranged from 213 to 5597 ng/g substrate. Aflatoxin was quantitated by using high pressure liquid chromatography (HPLC). Raw, non-autoclaved cocoa beans, also inoculated with aspergilli, produced 6359 ng aflatoxin/g substrate. Variation in aflatoxin production between bean varieties was observed. Total aflatoxin levels of 10,446 and 23,076 ng/g substrate were obtained on Ivory Coast beans inoculated with A. parasiticus NRRL 2999 and NRRL 3240, respectively. Aflatoxin production on Trinidad and Malaysian beans was 28 and 65 ng aflatoxin/g substrate. These data support previously reported low level natural aflatoxin contamination in cocoa.

Antioxidant enzymes stimulation in Aspergillus parasiticus by Lentinula edodes inhibits aflatoxin production

2005 ◽  
Vol 69 (2) ◽  
pp. 207-215 ◽  
Author(s):  
M. Reverberi ◽  
A. A. Fabbri ◽  
S. Zjalic ◽  
A. Ricelli ◽  
F. Punelli ◽  
...  
Keyword(s):  
Antioxidant Enzymes ◽  
Lentinula Edodes ◽  
Aspergillus Parasiticus ◽  
Aflatoxin Production

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.

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