• Journal of Food Hygiene and Safety
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• v.28 no.3
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• pp.267-271
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• 2013

A survey of aflatoxin $B_1$ and ochratoxin A was conducted on dried red pepper and red pepper powder. Total number of 193 samples were collected from local markets in Incheon. The presence of aflatoxin $B_1$ and ochratoxin A was determined by high performance liquid chromatography (HPLC) with fluorescence detector using immunoaffinity column clean-up. The recovery rate of aflatoxin $B_1$ and ochratoxin A were more than 80% and the limits of quantification were 0.13 ${\mu}g/kg$ for aflatoxin $B_1$ and 0.30 ${\mu}g/kg$ for ochratoxin A. Aflatoxin $B_1$ was detected in 33 samples (17.1%) with a range of 0.14~9.67 ${\mu}g/kg$ and ochratoxin A was detected in 40 samples (20.7%) with a range of 0.31~3.31 ${\mu}g/kg$. These results show that the occurrence of aflatoxin $B_1$ and ochratoxin A in dried red pepper and red pepper powder tested in this study is low compared with the standard in Korea Food Code (10 ${\mu}g/kg$ as aflatoxin $B_1$ and 7 ${\mu}g/kg$ as ochratoxin A).

• Korean Journal of Microbiology
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• v.24 no.3
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• pp.288-294
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• 1986

The effects of ginseng saponin and its related materials on aflatoxin production by Aspergillus parasiticus NRRL2999 in yeast extract sucrose (YES) medium were studied. Maximal production of aflatoxins by the mold in the medium occurred after 9 days at $28^{\circ}C$. When various concentrations of ginseng saponin were added to the medium aflatoxin productions were significantly reduced (p<0.05) compared to the control after 9 days at $28^{\circ}C$. 0.05% of saponin in the medium greatly decreased aflatoxin synthesis, and no aflatoxins were synthesized by the mold in the medium contained 5.0% of saponin. When various concentrations of saponin diol and triol were added to the medium both ingibitory and sitimulatory effects on alfatoxin production were resulted. Saponin fraction numbers of 1, 2, 4, 5 and 6 decreased aflatoxin production, however the numbers of 3 and 7 stimulated the toxin production. 0.05% of adenosine, guanosine, caffeine and xanthosine in the media inhibited aflatoxin production (p<0.05), but adenine and cytosine increased the production. When 5.0% of saponin was added to the medium aflatoxins were not synthesized at all, but total lipid synthesis and mold growth were highly stimulated. Both the synthesis of total lipid and mold growth were reduced in case of aflatoxin synthesis stimulated.

• 한국균학회소식:학술대회논문집
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• 2006.10a
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• pp.32-44
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• 2006

To investigate non-aflatoxin-production of A. oryzae at the molecular level, an aflatoxin biosynthesis gene homolog cluster of RIB 40 was analyzed. Although most genes in the corresponding cluster exhibited from 97 to 99 % similarity to those of Aspergillus flavus, three genes shared 93 % similarity or less. In addition, although slight expression of aflR, positive transcriptional regulator gene, was detected in some A. oryzae strains having seven aflatoxin biosynthesis homologous genes, other genes related to aflatoxin production were not detected. RIB strains were mainly divided into group 1, having seven aflatoxin biosynthesis homologous genes (aflT, nor-i, aflR, norA, avnA, verB, and vbs), and group 2, having three homologous (avnA, verB, and vbs). Partial aflatoxin homologous gene cluster of RIB62 from group 2 was sequenced and compared with that of RIB40 from group 1. RIB62 showed a large deletion upstream of ver-1 with more than half of the aflatoxin homologous gene cluster missing including aflR, a positive transcriptional regulatory gene. Adjacent to the deletion of the aflatoxin homologous gene cluster, RIB62 has a unique sequence of about 8kb and a telomere. Southern analysis of A. oryzae RIB strains with four kinds of probe derived from the unique sequence of RIB62 showed that all group 2 strains have identical hybridizing signals. Polymerase chain reaction with specific primer set designed to amplify the junction between ver-1 and the unique sequence of RIB62 resulted in the same size of DNA fragment only from group 2 strains. Based on these results, we developed a useful genetic tool that distinguishes A. oryzae group 2 strains from the other groups' strains and propose that it might have differentiated from the ancestral strains due to chromosomal breakage.

• Journal of Food Hygiene and Safety
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• v.15 no.2
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• pp.122-127
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• 2000

An antifungal bacterium was isolated to inhibit of the growth of Asp. flavus and Asp. parasiticus, and its antifungal compounds were purified from lyophilized culture broth using chromatographic methods. Antifungal bacterium #19 which was shown a higher inhibitory activity on the growth of aflatoxin producing fungi was identified as Bacillus subtilis. The purified antifungal compound(1 mg) was demonstrated strong antifungal activity against the aflatoxin producing fungi.

• The Journal of the Korean Society for Microbiology
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• v.10 no.1
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• pp.33-37
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• 1975

In view of the warmth and hunidity in Korea, there is little possibility to avoid the fungal contamination of rice soybean paste which are major foodstuffs in this country. In order to isolate aflatoxin producing fungi from these foodstuffs, 6 samples of rice were collected from the farmhouses at Cbangsung and 40 samples of soybean paste in Seoul areas. The peptone glucose chloramphenicol, Czapek-Dox agar and malt agar were used for the isolation and identification of fungi, and Adye and Meteles medium and/or Sahouraud medium for the production of toxins. The cultures for the toxin production were done at $25^{\circ}C$ for $5{\sim}7$ days. Eleven Penicillium species were isolated. from 6 samples of rice, and 37 Aspergillus flavus, 48 Aspergillus species, 1 Penicillium species and 105 others were isolated from 40 samples of soybean paste. Among these, one Penicillium species isolated from rice was found to be aflatoxin producing strain, and the toxin was quantitatively measured. Aflatoxin appeared to be more favorably produced in the glucose Sabouraud medium than in the Adye and Meteles medium.

• Korean Journal of Food Science and Technology
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• v.17 no.4
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• pp.295-303
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• 1985

Aflatoxin $B_1$, $B_2$, $G_1$, and $G_2$were quantitatively detected by the high pressure liquid chromatography on a Micropak-CN column, with Hexane-THF-IPA-water, using a Lichrosorbpacked flowceil in the fluorometric detector. Under those conditions, the minimum detectable amount of aflatoxin $B_1$ was 0.2 ng. HPLC was used in determining amount of aflatoxins in the commercially manufactured soybean food and home-made Meju. Aflatoxin producing abilities of strains used in the industrially fermented soybean food were also studied with the HPLC technique. Although aflatoxin-like substances were detected in a few samples on TLC, they were not identified with the HPLC retention times of standard aflatoxins. The commercial fungal strains used in Korea had no aflatoxin producing abilities.

• Mycobiology
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• v.45 no.3
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• pp.213-219
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• 2017

In our previous study, three bacterial strains, Bacillus megaterium KU143, Microbacterium testaceum KU313, and Pseudomonas protegens AS15, were selected as effective biocontrol agents against Aspergillus flavus on stored rice grains. In this study, we evaluated the inhibitory effects of the volatiles produced by the strains on A. flavus growth and aflatoxin production on stored rice grains. The three strains significantly reduced mycelial growth of A. flavus in dual-culture assays compared with the negative control strain, Sphingomonas aquatilis KU408, and an untreated control. Of these tested strains, volatiles produced by B. megaterium KU143 and P. protegens AS15 markedly inhibited mycelial growth, sporulation, and conidial germination of A. flavus on agar medium and suppressed the fungal populations in rice grains. Moreover, volatiles produced by these two strains significantly reduced aflatoxin production in the rice grains by A. flavus. To our knowledge, this is the first report of the suppression of A. flavus aflatoxin production in rice grains using B. megaterium and P. protegens volatiles.

• Journal of Environmental Health Sciences
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• v.31 no.2 s.83
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• pp.127-133
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• 2005

This study was performed to investigate the competitive effect of Leuconostoc mesenteroides and Lactobacillus plantarum on the growth and aflatoxin $B_1$ production of Aspergillus parasiticus. Leu. mesenteroides and Lac. plantarum were grown with A. parasiticus in a modified APT broth at $28^{\circ}C$ for 9 days. It was observed that the growth of A. parasiticus got lower when the two bacteria were inoculated simultaneously than when the mold grew alone. The pH of mixed culture of Leu. mesenteroides and Lac. plantarum showed significantly lower value than the pH of the pure culture of A. parasiticus (p<0.05). The acidity of the mixed culture group significantly increased compared with the control group (A. parasiticus alone group) (p<0.05). The aflatoxin $B_1$ production was significantly decreased in the mixed culture group than in the A. parasiticus alone group (p<0.05). Leu. mesenteroides showed the more efficient effect than Lac. plantarum. These results indicate that the two lactic acid bacteria have inhibitory effect on the growth and aflatoxin $B_1$ production of Aspergillus parasiticus.

• Journal of the korean veterinary medical association
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• v.26 no.9
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• pp.543-553
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• 1990

This report describes the cellular changes induced in the livers of ducklings by a sin91e administration of aflatoxin B$_1$ produced by Korean Industrial Strain of the Aspergillus flavus, in order to examine the toxicity of the minimum dose of

• Toxicological Research
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• v.8 no.1
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• pp.83-94
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• 1992

The influences of dietary aflatoxin B1 on performance, on hematologic, pathologic and immunologic changes in broiler chickens were studied. One hundred and fifty hatched broiler chickens were fed with diet containing aflatoxin B1 (1.0 ppm and 2.5 ppm) fot three weeks. Blood samples, serum, and immune organs were obtained to investigate hematological, clinico-chemical, and histopathologial changes. Body weight gain and feed intake were significantly decreased. The liver and kidney were increased, whereas the bursa of Fabricius, spleen and thymus were decreased.