• Title/Summary/Keyword: aflatoxin

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Studies on Changes of Aflatoxin Productivity and Properties by a Pseudomonad (녹농균과 진균류의 생물학적 상호작용에 의한 Aflatoxin 류의 생성능과 성질 변화에 대한 연구)

  • Lee, Young-Nam;Kim, Joo-Deuk
    • The Korean Journal of Mycology
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    • v.8 no.1
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    • pp.59-62
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    • 1980
  • Investigation on modification of aflatoxin structures by Pseudomonads was attempted as a biological detoxifiying process of mycotoxins. Firstly, when any variation of aflatoxin yield of Aspergillus parasiticus in a mixed culture with Pseudomonas aeruginosa was examined, there was no noticible effect by growth of Pseudomonads on aflatoxin yield of Asperillus sp. Secondly, when capacity of Pseudomonas aeruginosa utilizing aflatoxin as a carbon source for its growth was tested, there was some indication that aflatoxin might be used for growth of Pseudomonads. It was also noticed that the residual aflatoxin showed different migrating pattern compared with that of the intact aflatoxin by thin layer chromatography. Thirdly, the cell-free extract prepared from Pseudomonas aeruginosa grown in a glucose minimal medium supplemented with aflatoxin and the intact aflatoxins were incubated in the presence of $Mg^{++}$. After a certain length of incubation period, the reaction mixtures were applied on TLC plates. As a result, aflatoxins in the reaction mixture migrated differently as the control did. Such results may indicate that some changes of aflatoxin properties were induced by Pseudomonads.

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The Effect of Some Koji Molds on Production of Aflatoxin by Aspergillus flavus (몇가지 고오지 곰팡이가 Aspergillus flavus에 의한 Aflatoxin 생성에 미치는 영향)

  • Kim, Sung-Taek;Kim, Young-Bae
    • Applied Biological Chemistry
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    • v.29 no.3
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    • pp.255-259
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    • 1986
  • The aflatoxin production by Aspergillus ATCC 15517 decreased in the mixed culture with Aspergillus awamori, Aspergillus kawachii, Aspergillus niger, Aspergillus oryzae, or with Aspergillus shirousamii to 1.3%, 13.8%, 1.3%, 0.7%, or 38.5% of that of monoculture respectively. These koji molds degraded $75%{\sim}100%$ of added aflatoxin $B_1\;(791{\mu}g/50ml\;YES medium)$. A. awamori secreted during growth aflatoxin degrading factor(s) which was heat-labile. The degraded aflatoxin by the factor(s) showed no toxicity against Bacillus megaterium NRRL B-1368.

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Producibility of Aflatoxin by Aspergillus parasiticus in Barley and Their Radiosensitivity (Aspergillus parasiticus에 의한 보리의 Aflatoxin 생성(生成)과 감마선(線)의 영향(影響))

  • Chang, Hak-Gil;Markakis, Pericles
    • The Korean Journal of Mycology
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    • v.9 no.1
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    • pp.1-6
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    • 1981
  • The effect of gamma irradiation on production and accumulation of aflatoxin on natural substrate (barley) by Aspergillus parasiticus NRRL 2999 has been studied in some detail. Gamma irradiation at five doses, 0, 50, 100, 200 and 400 Krad was applied to the grain either soon after moisture equilibration (3 days after inoculation) or 10 days later (13 days after inoculation). And the results were as in the followings. 1. Increase in moisture content from 17% to 25% greatly increased the aflatoxin concentration, especially at zero irradiation dose. 2. Prolongation of the incubation period prior to irradiation from 3 to 13 days resulted in greater accumulation of aflatoxin. 3. Two hundreds Krad applied 13 days after inoculation on barley stored at 25% moisture (100% RH) and $25^{\circ}C$ led to higher aflatoxin production than 100 Krad or even 50 Krad. 4. The relative proportion of the principal aflatoxins in relation to irradiation showed that aflatoxin G was elaborated at a significantly higher rate than aflatoxin B.

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Effect of Temperature on Aflatoxin Production in Barley by Aspergillus parasiticus (Aspergillus parasiticus에 의(依)한 보리의 아플라톡신 생성(生成)에 대(對)한 온도(溫度)의 영향(影響))

  • Chang, Hak-Gil;Markakis, Pericles
    • Korean Journal of Food Science and Technology
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    • v.14 no.2
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    • pp.162-167
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    • 1982
  • The influence of temperature and moisture on aflatoxin production on solid substrate(barley) by Aspergillus parasiticus NRRL 2999 has been studied in some detail. The optimum temperature for production of aflatoxin under the conditions employed is 25 and $30^{\circ}C$. No aflatoxin was detected at the moisture levels of 13%, and only traces at 16% moisture. The ratio of the production of aflatoxin B to G varied with temperature and moisture level. Aflatoxin G is elabolated at a more rapid rate than B and also metabolized at a more rapid rate. Also lower temperatures favored the production of aflatoxin G. The intensity of the yellow pigment of the chloroform extracts correlated with the concentration of aflatoxin.

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Inhibitory Effects of Grapefuit Seed Extract on Growth and Aflatoxin Production of Aspergillus parasiticus (Grapefruit 종자추출물을 이용한 Aspergillus parasiticus의 생육 및 Aflatoxin 생성억제 효과)

  • 조성환;정덕화;서일원;이현숙;황보혜;박우포
    • Journal of Food Hygiene and Safety
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    • v.7 no.1
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    • pp.15-22
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    • 1992
  • This study was conducted to determine the potential of grapefruit seed extract to support Aspergillus parasilicus growth and aflatoxin production. The grapefruit seed extract inhibited the growth and aflatoxin production of the fungi in the level of more than 4,000 ppm and 3,000 ppm in the medium, respectively. Grapefruit seed extract appears to block the conversion of acetate, averufin and versiconal acetate into aflatoxin in vitro experiments. The addition of grapefruit seed extract to the feeding experiment systems did not inhibit the incorporation of 14C-labeled versicolorin A, versicolorin A hemiacetal and sterigmatocystin into aflatoxin. In the electron microscopic examination the biocidal action of grapefruit seed extract was related to the disturbance of cell menbrane funtion, inhibiting cellular respiration.

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General characters and applications of photosynthetic bacteria (광합성세균의 생리 및 이용에 관한 최근의 동향)

  • 이광웅
    • Korean Journal of Microbiology
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    • v.9 no.3
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    • pp.130-138
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    • 1971
  • In order to investigate the production of aflatoxin in various conditions such as pH, moisture and temperature, 27 smaples were inoculated with Aspergillus flavus, and in addition 3 smaples were inoculated with the mixture of Aspergillus flavus and Bacillus subtilis and cultured under the conditions such as 20.deg.C and 30% moisture contents. The following results were obtained : 1) Aflatoxin production was the highest at pH 5.0 and relatively high at pH 7.0. Its production was decreased significantly when pH reached 9.0. 2) The yield of aflatoxin was shown comparatively high level at 30% moisture contens. The higher moisture contents was, the lower aflatoxin production was. 3) The highest level of aflatoxin production was at 20.deg,C, and comparatively high level was at 30.deg.C. However, its production was fairly low at 40.deg.C. 4) The highest crude aflatoxin production was 5,093ppm (B$_{1}$, 1.912ppm ; B$_{2}$, and the lowest one 2.197 ppm (B$_{1}$, 0.793 ppm : B$_{2}$, 0.185 ppm : G$_{1}$ ,0.102 ppm G$_{2}$, 0.381ppm) at 63% moisture, pH 9.0 and 40.deg.C. 5) When Aspergillus flavus and Bacillus subilis were cultured together under the conditions such as 20.deg.C and 30% moisture, aflatoxin production was decreased by 27% comparing with the culture of Aspergillus flavus alone.

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Hygienic Studies on the Agricultural Products in Youngnam Districts (Part II) Determination of Aflatoxin B1 by ELISA Method (영남지방 농상물에 대한 위생학적 연구(제2보) ELISA 법에 의한 Aflatoxin B1 검색)

  • ;;;;James J. Pestka
    • Journal of Food Hygiene and Safety
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    • v.4 no.3
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    • pp.171-176
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    • 1989
  • A rapid, simple method of ELISA was applied for the determination of aflatoxin BI in cereals from Y oungnam districts. Antibodies obtained cross reacted with aflatoxin B2 and to a less extent with other aflatoxin BI analogs. Response range for a typical standard curve was between I and 100 ppb. Fewer interference by spiked methanol-PBSdimethylformamide extracts ofrice was evidenced. Contents of aflatoxin BI from rice (65) and barley (116) were determined by competitive direct enzyme- linked immunosorbent assay as follows. Three out of 65 rices samples were positive. Rice samples of R-IS, R-30, and R-59 represent the aflatoxin B1 levels of $7.5\;\mu\textrm{g}.kg,\;6.0\;\mu\textrm{g}/kg,\;3.5\;\mu\textrm{g}/kg,\;3.3\;\mu\textrm{g}/kg$, respectively, and showed 4.6% aflatoxin BI contamination in rice samples. Meanwhile, four out of 116 barley samples were positive. VB-37 showed the highest aflatoxin Bllevels of $9.6\;\mu\textrm{g}/kg$ and VB-35, VB-15 and VB-54 represent $7.5\;\mu\textrm{g}.kg,\;6.0\;\mu\textrm{g}/kg\;and\;3.6\;\mu\textrm{g}/kg$, respectively, and showed 3.4% aflatoxin B1 contamination in barley samples.

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Incubation Conditions and Physico-Chemical Factors Affecting Aflatoxin B1 Binding of Lactic Acid Bacteria (Aflatoxin B1에 대한 유산균의 결합력에 영향을 미치는 배양조건과 물리화학적 인자)

  • Lim, Sung-Mee;Ahn, Dong-Hyun
    • Korean Journal of Microbiology
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    • v.49 no.3
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    • pp.253-261
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    • 2013
  • The purpose of this study was to investigate the aflatoxin $B_1$ binding of lactic acid bacteria (LAB) isolated from Korean traditional soybean paste and to evaluate the effect of incubation conditions and physico-chemical factors on the binding ability of LAB to this mutagen. The amount of aflatoxin $B_1$ bound by Enterococcus faecium DJ22, Lactobacillus fermentum DJ35, Lactobacillus rhamnosus DJ42, and Lactobacillus pentosus DJ47 was strain specific with the percent bound ranging from 19.3% to 52.1%. However, Enterococcus faecalis DJ14, Lactobacillus panis DJ29, and Pediococcus halophilus DJ50 strains did not exhibit any of the binding ability to aflatoxin $B_1$. For most strains, the binding ability was significantly affected by the environmental conditions such as the aflatoxin $B_1$ level, incubation time and temperature, and the initial cell count of LAB. The stability of the aflatoxin $B_1$-bacteria complexes was significantly more unstable after washing. In addition, the binding stability between viable and nonviable cells was not statistically significant. Treatment with heating, acidic pH, ${\alpha}$-amylase, protease, lysozyme, or sodium metaperiodate caused a significant (P<0.05) decrease in aflatoxin $B_1$ binding for the tested strains, suggesting that carbohydrates or proteins in the cell walls may be involved in aflatoxin $B_1$ binding ability. Since the aflatoxin $B_1$ binding of LAB was significantly reduced (P<0.05) by the pretreatment of the urea, the binding force observed in this study may have resulted from hydrophobic interaction.

Analysis of Peanut and Peanut Butter Retailed in Korea for Aflatoxin $B_1$ (국내 시판 땅콩 및 땅콩버터 중 Aflatoxin $B_1$ 오염 분석)

  • Park, Je-Won
    • Korean Journal of Food Science and Technology
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    • v.38 no.2
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    • pp.309-312
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    • 2006
  • Aflatoxin $B_1$ in 70 retail samples, including 40 food-grade peanut (28 domestic, 12 imported) and 30 peanut butter (12 domestic, 18 imported) samples, was analyzed by high-performance liquid chromatography (HPLC) with fluorescence detection (FD), and positive samples were confirmed using HPLC with mass spectrometry (MS). Recoveries of aflatoxin $B_1$ spiked at 2 ppb exceeded 80% in both commodities. Detection limits for aflatoxin $B_1$ by HPLC-FD and MS analysis were 0.8 and 0.1 ppb, respectively. Four domestic and six imported peanut samples contained detectable levels of aflatoxin $B_1$ with means of 19 and 32 ppb, respectively. Aflatoxin $B_1$ was found in two domestic and three imported peanut butter samples with mean aflatoxin $B_1$ of 10 and 12 ppb, respectively. Peanut commodity showed more frequent aflatoxin $B_1$ contamination compared to its processed peanut butter product, and levels of aflatoxin $B_1$, especially in imported peanuts, were significantly (p<0.05) higher than those of other commodities. These results suggest peanut and peanut butter are not major contributors to dietary intake of aflatoxin $B_1$ in South Korea.

Selection of Resistant Varieties to Aspergillus flavus by Determination of Aflatoxin B1 Content in Korean Peanut (Arachis hypogaea L.) Accessions

  • Seungah Han;Byeong-Cheol Kim;Jungmin Ha;Tae-Hwan Jun
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.68 no.3
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    • pp.175-187
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    • 2023
  • Peanuts, also known as groundnuts (Arachis hypogaea L.), are globally recognized as a vital oilseed crop. Peanuts are rich in proteins (e.g., arginine), oils (e.g., oleic acid and linoleic acid), fiber, vitamins (e.g., niacin and tocopherol), and carbohydrates and are consumed worldwide. However, the presence of aflatoxin (AF) has garnered substantial attention since its initial discovery as the causative agent of Tukey's X disease in the United Kingdom in 1960. Among the 18 aflatoxins identified, aflatoxin B1 (AFB1) has the highest toxic activity and causes hepatocellular carcinoma. It is classified as Group I by the International Agency for Research on Cancer (IARC) of the World Health Organization (WHO). The present study was conducted to evaluate aflatoxin B1 resistance of 102 peanut accessions and select putative aflatoxin B1-resistant peanut accessions to aflatoxin B1. One hundred and one Korean germplasms harvested in 2020 were inoculated with A. flavus to identify aflatoxin-resistant cultivars, and the aflatoxin B1 concentration was measured using an ultra-performance liquid chromatography-photodiode array detector. Twenty-six accessions with aflatoxin B1 concentrations lower than those of the check plant 55-437 were chosen for the development of aflatoxin-resistant varieties in Korea. As Korean aflatoxin-resistant varieties have not yet been developed, the findings of the present study are expected to provide useful information for the development of aflatoxin-resistant cultivars.