• The Korean Journal of Mycology
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• v.20 no.3
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• pp.252-258
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• 1992

Thirty three species and two species varieties belonging to 14 genera of fungi were collected from 20 cowpea cultivars on glucose Czapek's agar (11 genera and 25 species+1 var.) and glucose-Czapek's agar supplemented with 10% NaCl (7 genera and 18 species+2 var.) at $28{\pm}2^{\circ}C$. The total count of fungi were 6716 colonies/g in all cowpea cultivars. On glucose-Czapek's agar and identified; Aspergillus flavus, A. niger, A. sydowii, A. flavus var. columnaris, A. terreus, Penicillium chrysogenum, Emericella nidutans and Rhizopus stolonifer. The total count of halotolerant or halophilic fungi was 3515 colonies/g on 10% NaCl-glueose-Czapek's agar and identified; the most common species were: A. flavus, A. sydowii, A. tamarii A. flavipes, A. niger, A. flavus var. columnaris, A. ochraceus, A. oryzae and P. chrvsogenusm. Thin layer chrormatographic analysis of chloroform extracts of the different seed samples revealed that four cultivars were naturally contaminated with aflatoxins $B_1,\;B_2,\;G_1$ and $G_2$, $(45-112\;{\mu}g/kg)$.

• Korean Journal of Pharmacognosy
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• v.45 no.2
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• pp.154-160
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• 2014

The aim of this study was to determine the incidence and contamination levels of aflatoxin in Medicinal Herbs for Food and Medicine at Yakyeang market in seoul. 191 Samples 11 items medicinal herbs for food and medicine were evaluated for the aflatoxin contamination. in result 41 samples 10 items (21.5%) were detected in the alfatoxin, a high incidence of aflatoxins items are cassiae semen (50.0%), testudinis plastrum (43.8%) and Batryticatus Bombyx (40.0%), Polygalae Radix (31.2%), Zizyphi Semen (23.5%), Dolichoris Semen, Myristicae Semen (20.0%), Nelumbinis Semen (15.8%), Glycyrrhizae Radix et Rhizoma (7.4%), Hoveniae Semen Cum Fructus (4.3%). AFB1 were detected 27 cases (14.1%), AFB2, AFG1 and AFG2 were detected 18cases (9.4%), 16cases (8.4%) and 5cases (2.6%). The excess cancer risk estimated using the cancer potency of aflatoxin B1 (7(mg/kg/day)-1 for HBsAg-and 230(mg/kg/day)-1 HBsAg+) was N.D ~ $3.79{\times}10^{-6}$ for hepatits B surface antigen negative (HBsAg-) and N.D ~ $9.68{\times}10^{-5}$ hepatits B surface antigen positive (HBsAg+) respectively.

• Environmental Analysis Health and Toxicology
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• v.5 no.3_4
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• pp.29-36
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• 1990

Aflatoxins, produced by strains of Aspergillus flavus and Aspergillus parasiticus, can be found worldwide in corn, barley, peanuts, and other commodities. Among this group of toxins, aflatoxin B$_1$was realized to be one of the most potent environmental carcinogens, mutagens and teratogens. It is routinely monitored by methods such as thin layer chromatography, liquid chromatography, fluorodensitometric technique and radioimmunoassay. However, these assays are expensive, necessitate radioactive reagents, and require overnight incubation. In this study, the determination of fungal flora in several sorts cereals has been carried out in order to obtain an appropriate information of the population of fungi. The quantitative analysis of aflatoxin B$_1$has been carried out by High Performance Liquid Chromatography (HPLC) method and Enzyme Linked Immunosorbent Assay (ELISA). The results were summarized as follow: 1) From the 100 samples,313 colonies of fungi were isolated. Among the 313 colonies, 274 were possible to identify into 11 genera. The identified genera were Aspergillus Penicillium, Mucor, Rhizopus, Alternaria, Cladosorium, Fusarium, Circinella, Chrysosporium, Paecilomyces and Phoma. 2) Six of Aspergillus flavus were aflatoxin-producing strains. Aspergillus flavus isolated from sample barleys was contained the highest content (21.8 $\mu\textrm{g}$/ml) of aflatoxin B$_1$. 3) The yield of aflatoxin B$_1$-oxime compound was appromately 75%. Aflatoxin B$_1$-oxime-Human serum albumin was approved by formal consent as complete antigen. 4) Direct competitive ELISA permitted detection of 0.15 ng levels. In the quantitative microanalysis, ELISA was superior to HPLC method.

• Korean Journal of Veterinary Service
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• v.39 no.3
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• pp.167-174
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• 2016

In this study, we analyzed for the changes of low organic compounds during 4 weeks incubation though inoculation of harmful microorganisms on commercial feed. Two percent of overnight cultures of Exiguobacterium acetylicum, Acinetobacter calcoaceticus, Aspergillus flavus and Fusarium graminearum were inoculated in feed, respectively. After adjusting moisture level to 50% for the promotion of feed spoilage, pH was decreased to 4.58~5.03 and microorganism was ranged to $6{\sim}10log_{10}CFU/g$. The compounds were compare between aflatoxin G1 producing feeds and aflatoxin G1 non-producing feeds. Aflatoxins G1 were detected by the immunoaffinity column clean-up method with HPLC-FLD, and were confirmed in samples incoulated by Aspergillus flavus and Acinetobacter calcoaceticus. Koiganal II, cyclohexanol and butadien-one were detected from samples (the non-sterilized inoculated feed) by Aspergillus flavus and Acinetobacter calcoaceticus. Respectively as aflatoxin G1 pre-detected substance, Koiganal II, cyclohexanol and butadien-one may be useful substance for the pre-detection of aflatoxin G1.

• The Korean Journal of Mycology
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• v.3 no.1
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• pp.31-36
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• 1975

In 1963, a severe epidemic of cereal scab caused by Gibberella zeae occurred in southern Korea and to a less extent in central and northern Korea. In some areas losses were $80{\sim}100$ percent. The epiphytotic was due to heavy rainfall during the heading and flowering season which provided a favorable environment for this severe epidemic. Yield losses resulted a great social problem because of the resultant food and feed grain shortage, lose of seeds for planting the following crops and mycotoxicoses to man and animals. In the same year, a nationwide research committee was organized including plant pathologists, microbiologists, agronomists and biochemists under the juristiction of the Ministry of Agriculture and Forestry. The committee initiated research on etiology, epidemiology, and control of the disease and on the toxic effect of infected grains to man and animals. The present paper will review some research carried out in Korea on cereal scab with special reference to epidemiology and mycotoxicoses to animals and man. In addition, the present status of research in Korea on aflatoxins in foods and toxic moldy rice will be briefly reviewed.

• The Korean Journal of Mycology
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• v.10 no.2
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• pp.89-92
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• 1982

The seeds of 20 barley cultivars were tested for aflatoxin contamination and susceptibility to infection by an aflatoxin-producing mold. When the samples were tested as they arrived, no aflatoxin was detected on any of them. When their moisture was raised to 25% and they were kept as $25^{\circ}C$ for 2 weeks, all expect 2 cultivars showed aflatoxin contamination. Aflatoxins $B_2$ and $G_2$ were not detected in this incubation period. After wetting (25% moisture) the samples, inoculating them with Aspergillus parasiticus conidia and storing them at $25^{\circ}C$ for 2 weeks, all cultivars were found heavily contaminated with aflatoxin, those with seedcoats more so than those without seedcoats.

• Journal of Microbiology and Biotechnology
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• v.16 no.4
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• pp.643-646
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• 2006

Because of potential health hazards of aflatoxins for humans, the present study was conducted to monitor aflatoxin $B_1\;(AFB_1)$ in livestock feeds. A total of 249 samples of feeds collected in Korea were analyzed by DC-ELISA for qualitative analysis of $AFB_1$. Then, 27 samples that were verified to contain $AFB_1$ by DC-ELISA were quantitated by HPLC/FLD. HPLC/FLD analysis revealed that only one sample collected from a farm contained 11 ppb of $AFB_1$, whereas the other samples collected from feed companies did not contain $AFB_1$. The presence of $AFB_1$ was further confirmed by LC/MS analysis. TLC analysis indicated that the result of the DC-ELISA was most likely due to possible contamination of other mycotoxins rather than $AFB_1$. In conclusion, HPLC/FLD analysis following DC-ELISA is necessary for rapid and accurate detection of $AFB_1$.

• Toxicological Research
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• v.35 no.1
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• pp.1-7
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• 2019

Mycotoxin contamination is a global phenomenon and causes a wide array of negative effects and other complications. This study focused on commonly found mycotoxins in Africa and the possible means of prevention or reduction of their contaminating effects. Mycotoxins are secondary metabolites of mold and fungi; they are generally toxic to living organisms. Hundreds of mycotoxins have been identified thus far, with some, such as aflatoxins, ochratoxins, trichothecenes, zearalenone, fumonisins, and patulin, considered agro-economically important. Several factors contribute to the presence of mycotoxins in food, such as climatic conditions, pest infestation, and poor harvest and storage practices. Exposure to mycotoxins, which occurs mostly by ingestion, leads to various diseases, such as mycotoxicoses and mycoses that may eventually result in death. In light of this, this review of relevant literature focuses on mycotoxin contamination, as well as various methods for the prevention and control of their prevalence, to avert its debilitating consequences on human health. Clear evidence of mycotoxin contamination is present in Africa, and it was therefore recommended that adequate prevention and control of these toxic substances in our food system should be encouraged and that appropriate measures must be taken to ensure food safety as well as the enhanced or long-lifespan of the African populace. Governments, research institutions, and non-governmental organizations should tailor the limited resources available to tackle mycotoxin prevalence, as these will offer the best prospects for successful development of a sustainable food system in Africa.

• 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.

• Genomics & Informatics
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• v.21 no.4
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• pp.48.1-48.8
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• 2023

Liver cancer is the fourth leading cause of death worldwide. Well-known risk factors include hepatitis B virus and hepatitis C virus, along with exposure to aflatoxins, excessive alcohol consumption, obesity, and type 2 diabetes. Genomic variants play a crucial role in mediating the associations between these risk factors and liver cancer. However, the specific variants involved in this process remain under-explored. This study utilized a bioinformatics approach to identify genetic variants associated with liver cancer from various continents. Single-nucleotide polymorphisms associated with liver cancer were retrieved from the genome-wide association studies catalog. Prioritization was then performed using functional annotation with HaploReg v4.1 and the Ensembl database. The prevalence and allele frequencies of each variant were evaluated using Pearson correlation coefficients. Two variants, rs2294915 and rs2896019, encoded by the PNPLA3 gene, were found to be highly expressed in the liver tissue, as well as in the skin, cell-cultured fibroblasts, and adipose-subcutaneous tissue, all of which contribute to the risk of liver cancer. We further found that these two SNPs (rs2294915 and rs2896019) were positively correlated with the prevalence rate. Positive associations with the prevalence rate were more frequent in East Asian and African populations. We highlight the utility of this population-specific PNPLA3 genetic variant for genetic association studies and for the early prognosis and treatment of liver cancer. This study highlights the potential of integrating genomic databases with bioinformatic analysis to identify genetic variations involved in the pathogenesis of liver cancer. The genetic variants investigated in this study are likely to predispose to liver cancer and could affect its progression and aggressiveness. We recommend future research prioritizing the validation of these variations in clinical settings.