• Journal of Microbiology and Biotechnology
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• 제26권10호
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• pp.1687-1695
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• 2016

Ochratoxin A (OTA), a mycotoxin, contaminates agricultural products and poses a serious threat to public health worldwide. Microbiological methods are known to be a promising approach for OTA biodegradation because physical and chemical methods have practical limitations. In the present study, a total of 130 fungal isolates obtained from 65 traditional Korean meju (a fermented starter for fermentation of soybeans) samples were examined for OTA-biodegradation activity using thin-layer chromatography. Two fungal isolates were selected for OTA-biodegradation activity and were identified as Aspergillus tubingensis M036 and M074 through sequence analysis of the beta-tubulin gene. After culturing both A. tubingensis isolates in Soytone-Czapek medium containing OTA (40 ng/ml), OTA-biodegradation activity was analyzed using high-performance liquid chromatography (HPLC). Both A. tubingensis strains degraded OTA by more than 95.0% after 14 days, and the HPLC analysis showed that the OTA biodegradation by the A. tubingensis strains led to the production of ochratoxin α, which is much less toxic than OTA. Moreover, crude enzymes from the cultures of A. tubingensis M036 and M074 led to OTA biodegradation of 97.5% and 91.3% at pH 5, and 80.3% and 75.3% at pH 7, respectively, in a buffer solution containing OTA (40 ng/ml) after 24 h. In addition, the OTA-biodegrading fungi did not exhibit OTA production activity. Our data suggest that A. tubingensis isolates and their enzymes have the potential for practical application to reduce levels of OTA in food and feed.

• International Journal of Industrial Entomology and Biomaterials
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• 제33권1호
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• pp.1-5
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• 2016

Beauveria bassiana is a common fungal pathogen of Protaetia brevitarsis larvae, and although it is less common than Metarhizium anisopliae , the pathogen still poses a great risk to humans and animals that consume infected insects, owing to B. bassiana's production of toxins like beauvericin and mycotoxin. Interestingly, the beneficial microorganism Saccharomyces cerevisiae possesses antifungal properties. In the present study, we found that S. cerevisiae inhibited the growth of B. bassiana by 97% and that S. cerevisiae failed to harm P. brevitarsis when administered via intracoelomic injection (1×10⁷ cfu/mL). In addition, we also found that S. cerevisiae consumption increased the survival time of percutaneously infected P. brevitarsis larvae by 5 d and reduced the mortality of infected larvae by 12%. Therefore, S. cerevisiae is expected to be useful in the prevention and control of B. bassiana in the production of P. brevitarsis larvae.

• 한국식품저장유통학회지
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• 제14권3호
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• pp.315-322
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• 2007

국내산 사과로부터 분리, 동정한 P. crustosum과 patulin 생성균주인 P. griseofulvum(ATCC 46037)에 대하여 malt extract broth(MEB), sucrose yeast broth(SY) 및 5% glucose, yeast extract, peptone(5-GYEP) broth를 이용하여 생육정도와 독소 생성능을 비교하였다. 또한 균체 생육도와 독소 생성능과의 상관성을 검토하고, 배양액의 pH에 따른 균체 생장과 patulin 생성능을 조사하였다. P. griseofulvum(ATCC 46037)의 균체성장은 SY배지 에서 가장 높았으나 patulin은 SY, MEB, 5-GYEP 배지 모두에서 2,000-3,000 ppm의 높은 생산능을 보여주었다. P. crustosum의 균체생장 역시 SY배지에서 가장 높았으나 patulin 생성능은 5-GYEP broth 에서 배양 3주에 2,794 ppm으로 가장 높게 나타났다. P. crustosum과 P. griseofulvum 모두 균체생장과 patulin 생산능과의 상관관계는 매우 낮은 것으로 나타났다. 배지의 pH에 따른 patulin 생산능은 P. griseofulvum은 경우 pH 3-11의 넓은 범위에서 patulin 생성능을 나타내었으나, P. crustosum은 pH 3-5의 산성조건에서 높은 patulin 생성능을 나타내었다. 탄소원에 따른 patulin 생산능은 P. griseofulvum은 glycerol에서, P. crustosum은 fructose에서 가장 높았다.

• The Plant Pathology Journal
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• 제28권3호
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• pp.259-269
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• 2012

Protein phosphatase 2A (PP2A), a family of serine/threonine protein phosphatases, plays an important role in balancing the phosphorylation status of cellular proteins for regulating diverse biological functions in eukaryotic organisms. Despite intensive studies in mammals, limited information on its role is available in filamentous fungi. Here, we investigated the functional roles of genes for a putative B' delta regulatory subunit (FgPP2AR) and a catalytic subunit (FgPP2AC) of PP2A in a filamentous ascomycete, Fusarium graminearum. Molecular characterization of an insertional mutant of this plant pathogenic fungus allowed us to identify the roles of FgPP2AR. Targeted gene replacement and complementation analyses demonstrated that the deletion of FgPP2AR, which was constitutively expressed in all growth stages, caused drastic changes in hyphal growth, conidia morphology/germination, gene expression for mycotoxin production, sexual development and pathogenicity. In particular, overproduction of aberrant cylindrical-shaped conidia is suggestive of arthroconidial induction in the ${\Delta}FgPP2AR$ strain, which has never been described in F. graminearum. In contrast, the ${\Delta}FgPP2AC$ strain was not significantly different from its wild-type progenitor in conidiation, trichothecene gene expression, and pathogenicity; however, it showed reduced hyphal growth and no perithecial formation. The double-deletion ${\Delta}FgPP2AR;{\Delta}FgPP2AC$ strain had more severe defects than single-deletion strains in all examined phenotypes. Taken together, our results indicate that both the putative regulatory and catalytic subunits of PP2A are involved in various cellular processes for fungal development in F. graminearum.

• The Plant Pathology Journal
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• 제24권4호
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• pp.417-422
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• 2008

Apicidin is a cyclic tetrapeptide produced by some Fusarium species and is known to inhibit Apicomplexan histone deacetylase. The goals of this study were to determine species identity of Fusarium isolate KCTC16676, an apicidin producer, to improve a method for apicidin extraction, and to test phytotoxicity of apicidin and its analogs. We compared sequences of the translation elongation factor 1-alpha (TEF) gene in KCTC16676 with those from isolates representing diverse Fusarium species, which showed that KCTC16676 belongs to the F. semitectum-F. equiseti species complex. To enhance apicidin production, after culturing isolate KCTC16676 on a wheat medium for 3 weeks at $25^{\circ}C$, the culture was extracted with chloroform. Apicidins were purified through a reverse phase $C_{18}$ silica gel column, resulting in 5 g of apicidin, 200 mg of apicidin A, and 300 mg of apicidin $D_2$ from 4 kg of wheat cultures; this represents a significant yield improvement from a previous method, offers more materials to study the modes of its action, and facilitates the elucidation of the apicidin biosynthesis pathway. Apicidin and apicidin $D_2$ showed phytotoxicity on both seedlings and 2-week-old plants of diverse species, and weeds were more sensitive to apicidins than vegetables

• 한국식품위생안전성학회지
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• 제23권3호
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• pp.177-181
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• 2008

희나리 고추에서 분리한 곰팡이를 현미에 배양하여 실험동물(rat)에 투여하였을 때 Colletotrichum, Diaporthe, Diaporthopsis, Botryosphereia, Aspergillus, Fusarium의 경우 독성을 나타내지 않았으나 Alternaria alternata로 동정된 곰팡이는 독성을 나타내었다. A. alternata를 배양한 현미를 투여한 실험동물은 사료 섭취량이 상대적으로 낮았으며, 체중 감소를 보였고 2주안에 치사하였으며, 위, 소장, 간의 확대가 관찰되었다. Alternaria속 곰팡이는 17종이 분리되었으며 이들 중 8종은 고추즙과 현미에 배양하였을 때 모두 상당량의 tenuazonic acid를 생산하였고, 현미 배지에서만 alternariol과 alternariol monomethyl ether 독소가 추가로 소량 검출되었다. 건조 과정에서 곰팡이가 번식된 고추는 유해한 대사물의 존재 가능성이 있으므로 식품 안전을 위해 곰팡이 번식을 최대한 억제할 필요가 있다.

• Asian-Australasian Journal of Animal Sciences
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• 제16권5호
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• pp.706-713
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• 2003

Two experiments were conducted to evaluate the efficacy of dietary FERMKIT, a commercial toxin binder consisting of probiotic-fermented natural product containing chitin, chitosan and chitosan oligosaccharides ($FERMKITO^{(R)}$, EASY-BIO SYSTEM, Inc., Korea), in binding aflatoxin (AF) and zearalenone (ZEN) and ameliorating their mycotoxicity in meat type ducks. FERMKIT was supplemented to AF contaminated diets (at 120 ppb) at either 0.3 or 0.6% in experiment 1 and to ZEN contaminated diets (at 150 ppb) at 0.6% in experiment 2. In experiment 1 body weight gains were reduced by 37% and mortality was increased by 18% in ducks fed diet contaminated with AF at 120 ppb compared to ducks fed control diet (<10 ppb AF) for the 4-wk experimental period. However, dietary FERMKIT supplementation effectively alleviated overall toxicity induced by AF. The significant treatment-related changes in feather growth, web-toe hemorrhage, leg deformity, liver paleness, organ weights, hematological values and serum biochemical values, as compared to the control, were observed. The FERMKIT supplementation significantly diminished the adverse effects of AF and restored all the parameters measured back (<0.05) toward the control values. These findings indicated that FERMKIT, when added at the levels of 0.3 or 0.6% in the 120 ppb AF diets, could modulate the toxicity of AF with percentage sorption capacity of 52.70% at the level 0.3% and 79.85% at the level 0.6% of the diets (experiment 1). In experiment 2, FERMKIT, when added at 0.6% to the 150 ppb ZEN diets for the 4-wk experimental period, diminished the toxicity as shown by body weight gain, weights of testicles, oviducts, Bursa of Fabricius and cloaca eversion score as compared with the controls (<10 ppb ZEN) and 150 ppb ZEN diet with no added FERMKIT. The findings indicated that FERMKIT could be protective against the effects of ZEN in young growing ducks with percentage sorption capacity of 67.11% as evaluated from toxicity index parameter measured when added at 0.6% of the diets containing 150 ppb ZEN.

• Asian-Australasian Journal of Animal Sciences
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• 제18권3호
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• pp.375-383
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• 2005

An experiment was conducted to study the protective role of polyherbal feed supplement (Growell) during induced mycotoxicosis in broilers. A total of 240 Vencobb broilers were divided at day old stage into eight equal groups. Group A served as control and was given plain feed, group B, D, F and H were given Growell at 0.35 g/kg of feed. Group C, D, G and H were given dietary aflatoxin $B_1$ at 0.2 ppm and groups E, F, G and H were given ochratoxin A at 0.2 ppm in feed to study effect of Growell on individual aflatoxicosis, ochratoxicosis and combined mycotoxicosis of broilers. The chicks were given their respective feeds from 1st day to 6th week of age and were vaccinated at 7th and 28th day of age with Lasota strain of Newcastle disease virus. There was no statistically significant effect of mycotoxins individually or in combination on body weight of broilers. However, body weights were highest in group B and lowest in co-mycotoxicated group G. Feed conversion ratio was best in group B followed by A, D, F, E, H and G. Significant improvement in haemoglobin values was observed in broilers due to feeding of Growell in ochratoxin and co-mycotoxicated groups. There was no significant effect of mycotoxin treatment on PCV, TEC and TLC of broilers. Due to single and combined mycotoxicosis, there was reduction in serum total protein, albumin, cholesterol and triglyceride and rise in alkaline phosphatase, creatinine and uric acid levels. Supplementation of diets with Growell reduced the alterations induced due to mycotoxins. There was a significant rise in per cent organ weight of liver and reduction of that of spleen, bursa of Fabricius and thymus of broilers fed mycotoxins. Protection from alteration in per cent organ weight of these organ by supplementation of Growell was recorded. The observed impaired immune response and histopathological changes in liver, kidney, spleen, bursa of Fabricius and thymus of broilers given mycotoxins were protected by supplementation of Growell.

• The Plant Pathology Journal
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• 제32권3호
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• pp.182-189
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• 2016

Together with the Fusarium graminearum species complex, F. culmorum is a major member of the causal agents of Fusarium head blight on cereals such as wheat, barley and corn. It causes significant yield and quality losses and results in the contamination of grain with mycotoxins that are harmful to humans and animals. In Korea, F. culmorum is listed as a quarantine fungal species since it has yet to be found in the country. In this paper, we report that two isolates (J1 and J2) of F. culmorum were collected from the air at a rice paddy field in Korea. Species identification was confirmed by phylogenetic analysis using multilocus sequence data derived from five genes encoding translation elongation factor, histone H3, phosphate permease, a reductase, and an ammonia ligase and by morphological comparison with reference strains. Both diagnostic PCR and chemical analysis confirmed that these F. culmorum isolates had the capacity to produce nivalenol, the trichothecene mycotoxin, in rice substrate. In addition, both isolates were pathogenic on wheat heads and corn stalks. This is the first report on the occurrence of F. culmorum in Korea.

• Asian-Australasian Journal of Animal Sciences
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• 제14권12호
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• pp.1752-1757
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• 2001

The present study was conducted to assess the dietary effect of T-2 toxin on the antioxidant systems of the liver in growing quail and to comparatively evaluate the protective properties of two different mycotoxin-adsorbent additives, Mycosorb and zeolite, in preventing inhibition of the antioxidant system. Four groups of 4 day old quail were formed with 20 birds in each group. The birds were maintained on the floor for the course of the study. The three treatment diets consisted of the basal diet with T-2 toxin added in the form of Fusarium sporotrichioides culture (8.1 mg/kg feed), T-2 toxin (8.1 mg/kg) plus zeolite (30 g/kg feed), and T-2 toxin (8.1 mg/kg) plus Mycosorb (1 g/kg feed). After 30 days of feeding (34 days old) all birds were sacrificed and liver samples for biochemical analyses were collected from five quail in each of the four groups. Antioxidant concentrations were evaluated by HPLC-based methods. Inclusion of T-2 toxin in the quail diet was associated with a significant (p<0.05) decrease in concentrations of all forms of antioxidants studied, including ${\alpha}$- and ${\gamma}$-tocopherols, ascorbic acid, retinol and retinyl esters. At the same time, liver susceptibility to lipid peroxidation significantly (p<0.05) increased. Inclusion of zeolite in the quail diet at the level of 3% was ineffective in preventing antioxidant depletion in the liver by mycotoxicosis. In contrast, Mycosorb in the diet at a 0.1% level was able to significantly inhibit liver antioxidant depletion and as a result decreased lipid peroxidation in the liver. Concentrations of all forms of antioxidants studied were significantly higher in the livers of the quails fed the basal and T-2 toxin/Mycosorb combination in comparison to birds fed the basal with T-2 toxin alone.