• 한국균학회소식:학술대회논문집
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• 한국균학회 2016년도 춘계학술대회 및 임시총회
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• pp.33-33
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• 2016

Mycotoxins are toxic secondary metabolites produced by fungi. They can be present in where agricultural-based commodities are contaminated with toxigenic fungi. These mycotoxins cause various toxicoses in human and livestock when consumed. Small grains including corn, barley, rice or wheat are frequently contaminated with mycotoxins due to infection mainly by toxigenic Fusarium species and/or under environment favorable to fungal growth. One of the most well-known Fusarium toxin groups in cereals is trichothecenes consisting of many toxic compounds. Deoxynivalenol (DON), nivalenol (NIV), T-2 toxin, and various derivatives belong to this group. Zearalenone and fumonisin (FB) are also frequently produced by many species of the same genus. In order to monitor Korean cereals for contamination with Fusarium and other mycotoxigenic fungal species as well, barley, corn, maize, rice grains, and soybean were collected from fields at harvest or during storage for several years. The fungal colonies outgrown from the grain samples were identified based on morphological and molecular characteristics. Trichothecene chemotypes of Fusarium species or presence of FB biosynthetic gene were determined using respective diagnostic PCR to predict possible toxin production. Heavy grain contamination with fungi was detected in barley, rice and wheat. Predominant fungal genus of barley and wheat was Alternaria (up to 90%) while that of rice was Fusarium (~40%). Epicoccum also appeared frequently in barley, rice and wheat. While frequency of Fusarium species in barley and wheat was less than 20%, the genus mainly consisted of Fusarium graminearum species complex (FGSC) which known to be head blight pathogen and mycotoxin producer. Fusarium composition of rice was more diverse as FGSC, Fusarium incarnatum-equiseti species complex (FIESC), and Fusarium fujikuroi species complex (FFSC) appeared all at considerable frequencies. Prevalent fungal species of corn was FFSC (~50%), followed by FGSC (<30%). Most of FFSC isolates of corn tested appeared to be FB producer. In corn, Fusarium graminearum and DON chemotype dominate within FGSC, which was different from other cereals. Soybeans were contaminated with fungi less than other crops and Cercospora, Cladosporium, Alternaria, Fusarium etc. were detected at low frequencies (up to 14%). Other toxigenic species such as Aspergillus and Penicillium were irregularly detected at very low frequencies. Multi-year survey of small grains revealed dominant fungal species of Korea (barley, rice and wheat) is Fusarium asiaticum having NIV chemotype.

• 한국균학회지
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• 제46권1호
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• pp.1-8
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• 2018

국내에 보고되지 않은 3종의 균류가 담수환경으로 부터 분리되었다. NNIBRFG108은 강원도 삼척의 담수침전식물체에서 분리되었고, NNIBRFG1139와 NNIBRFG1480은 경북 김천과 제주지역의 토양으로부터 분리되었다. 형태적 특징 및 internal transcribed spacers (ITS), 18S rDNA, 28S rDNA 및 ${\beta}$-tubulin 유전자를 이용한 분자계통학적 분류를 통해 동정한 결과, NNIBRFG108, NNIBRFG1139, NNIBRFG1480 균주는 각각 Didymella segeticola, D. ellipsoidea 및 D. aeria으로 확인되었다. 이는 국내에서는 발견되지 않은 미기록종으로 본 보고가 국내 최초이다.

• Journal of Microbiology and Biotechnology
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• 제18권5호
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• pp.805-814
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• 2008

Liming of acidic soils can prevent aluminum toxicity and improve crop production. Some maize lines show aluminum (Al) tolerance, and exudation of organic acids by roots has been considered to represent an important mechanism involved in the tolerance. However, there is no information about the impact of liming on the structures of bacterial and fungal communities in Cerrado soil, nor if there are differences between the microbial communities from the rhizospheres of Al-tolerant and Al-sensitive maize lines. This study evaluated the effects of liming on the structure of bacterial and fungal communities in bulk soil and rhizospheres of Al-sensitive and Al-tolerant maize (Zea mays L.) lines cultivated in Cerrado soil by PCR-DGGE, 30 and 90 days after sowing. Bacterial fingerprints revealed that the bacterial communities from rhizospheres were more affected by aluminum stress in soil than by the maize line (Al-sensitive or Al-tolerant). Differences in bacterial communities were also observed over time (30 and 90 days after sowing), and these occurred mainly in the Actinobacteria. Conversely, fungal communities from the rhizosphere were weakly affected either by liming or by the rhizosphere, as observed from the DGGE profiles. Furthermore, only a few differences were observed in the DGGE profiles of the fungal populations during plant development when compared with bacterial communities. Cloning and sequencing of 16S rRNA gene fragments obtained from dominant DGGE bands detected in the bacterial profiles of the Cerrado bulk soil revealed that Actinomycetales and Rhizobiales were among the dominant ribotypes.

• Food Science and Biotechnology
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• 제17권4호
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• pp.888-891
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• 2008

Twenty-three fungal strains were isolated from meju that had originated from the Sunchang province, the famous location for making fermented soybean foods in Korea. The restriction fragment length polymorphism (RFLP) of the internal transcribed spacer (ITS) region of the rDNA (ITS-RFLP) was applied to differentiate the isolated fungal strains. First, the ITS region by polymerase chain reaction (PCR) with specific primers was amplified and then cleaved the products with different restriction enzymes. Cleavage of the amplified fragments with the restriction enzymes AluI, HaeIII, HhaI, and TaqI revealed extensive polymorphisms. The ITS-RFLP results highly correlated with ITS sequence analysis. All of the 23 fungal strains were classified into 5 groups by ITS-RFLP analysis. Aspergillus oryzae was the major fungal strain isolated from Sunchang meju (12 out of 23), while Aspergillus fumigatus was the next most frequently isolated strain (7 out of 23). In contrast, it was found that Fusarium asiaticum, Aspergillus sydowii, and Arthrinium sp. were the minor fungal strains in meju.

• Journal of Microbiology and Biotechnology
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• 제29권3호
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• pp.441-453
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• 2019

Organic farming is considered an effective form of sustainable agricultural management. However, understanding of soil microbial diversity and composition under long-term organic and conventional farming is still limited and controversial. In this study, the Illumina MiSeq platform was applied to investigate the responses of soil bacterial and fungal diversity and compositions to organic farming (OF) and improved conventional farming (CF, applied straw retention) in the rice-wheat rotation system. The results highlighted that the alpha diversity of microbial communities did not differ significantly, except for higher bacterial diversity under OF. However, there were significant differences in the compositions of the soil bacterial and fungal communities between organic and conventional farming. Under our experimental conditions, through the ecological functional analysis of significant different or unique bacterial and fungal taxonomic members at the phyla and genus level, OF enhanced nitrogen, sulfur, phosphorus and carbon dynamic cycling in soil with the presence of Nodosilinea, Nitrospira, LCP-6, HB118, Lyngbya, GOUTA19, Mesorhizobium, Sandaracinobacter, Syntrophobacter and Sphingosinicella, and has the potential to strengthen soil metabolic ability with Novosphingobium. On the other hand, CF increased the intensity of nitrogen cycling with Ardenscatena, KD1-23, Iamia, Nitrosovibrio and Devosia, but enriched several pathogen fungal members, including Coniochaeta, Corallomycetella, Cyclaneusma, Cystostereum, Fistulina, Curvularia and Dissoconium.

• Mycobiology
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• 제49권2호
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• pp.151-160
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• 2021

Despite recent studies, relatively few are known about the diversity of fungal communities in the deep Atlantic Ocean. In this study, we investigated the diversity of fungal communities in 15 different deep-sea sediments from the South Atlantic Ocean with a culture-dependent approach followed by phylogenetic analysis of ITS sequences. A total of 29 fungal strains were isolated from the 15 deep-sea sediments. These strains belong to four fungal genera, including Aspergillus, Cladosporium, Penicillium, and Alternaria. Penicillium, accounting for 44.8% of the total fungal isolates, was a dominant genus. The antiaflatoxigenic activity of these deep-sea fungal isolates was studied. Surprisingly, most of the strains showed moderate to strong antiaflatoxigenic activity. Four isolates, belonging to species of Penicillium polonicum, Penicillium chrysogenum, Aspergillus versicolor, and Cladosporium cladosporioides, could completely inhibit not only the mycelial growth of Aspergillus parasiticus mutant strain NFRI-95, but also the aflatoxin production. To our knowledge, this is the first report to investigate the antiaflatoxigenic activity of culturable deep-sea fungi. Our results provide new insights into the community composition of fungi in the deep South Atlantic Ocean. The high proportion of strains that displayed antiaflatoxigenic activity demonstrates that deep-sea fungi from the Atlantic Ocean are valuable resources for mining bioactive compounds.

• Journal of Microbiology and Biotechnology
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• 제31권11호
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• pp.1526-1532
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• 2021

Suaeda australis, Phragmites australis, Suaeda maritima, Suaeda glauca Bunge, and Limonium tetragonum in the Seocheon salt marsh on the west coast of the Korean Penincula were sampled in order to identify the endophytes inhabiting the roots. A total of 128 endophytic fungal isolates belonging to 31 different genera were identified using the fungal internal transcribed spacer (ITS) regions and the 5.8S ribosomal RNA gene. Fusarium, Paraconiothyrium and Alternaria were the most commonly isolated genera in the plant root samples. Various diversity indicators were used to assess the diversity of the isolated fungi. Pure cultures containing each of the 128 endophytic fungi, respectively, were tested for the plant growth-promoting abilities of the fungus on Waito-C rice germinals. The culture filtrate of the isolate Lt-1-3-3 significantly increased the growth of shoots compared to the shoots treated with the control. Lt-1-3-3 culture filtrate was analyzed and showed the presence of gibberellins (GA₁ 2.487 ng/ml, GA₃ 2.592 ng/ml, GA₉ 3.998, and GA₂₄ 6.191 ng/ml). The culture filtrate from the Lt-1-3-3 fungal isolate produced greater amounts of GA₉ and GA₂₄ than the wild-type Gibberella fujikuroi, a fungus known to produce large amounts of gibberellins. By the molecular analysis, fungal isolate Lt-1-3-3 was identified as Gibberella intermedia, with 100% similarity.

• Journal of the Korean Wood Science and Technology
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• 제31권1호
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• pp.46-51
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• 2003

본 연구는 라디에타소나무 제재목의 균 변색을 제거하기 위한 표백처리의 사용 가능성을 조사하기 위하여 수행하였다. 염소계 표백제인 아염소산나트륨과 차아염소산나트륨은 표백조건(약제농도, 처리온도, 처리시간)의 조절에 따라 만족할만한 변색제거 효과를 얻을 수 있었다. 비염소계 표백제인 과산화수소는 표백조건의 조절만으로는 변색제거가 불가능하였으나 규산나트륨과 수산화나트륨을 활성제로 첨가하는 경우에는 염소계 표백제보다 탁월한 변색제거 효과를 나타내었다. 그러나 활성제 첨가에 따라 재색의 녹색화 문제가 발생하였는데, 앞으로 이러한 문제점을 해결하기 위한 연구가 진행되어야 할 것이다. 또한, 앞으로 본 연구를 통해 개발된 변색제거 방법의 현장 적용을 위한 후속 연구도 필요하다고 본다.

• 한국건축시공학회지
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• 제24권1호
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• pp.43-53
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• 2024

본 연구에서는 실리콘 실란트 총 6종을 제작하여 곰팡이 저항성 시험 방법인 ASTM G 21, LH 전문 시방(LHCS 41 40 12) 시험과 신규 제정된 KS F ISO 21265 시험법에 따라 곰팡이 저항성을 평가하였다. 그 결과, KS F ISO 21265 시험법이 ASTM G 21과 LH 전문 시방(LHCS 41 40 12) 시험법에 비해 곰팡이 저항성 평가에 대한 변별성이 더 큰 것으로 판단되었으며, 알콕시 경화형 실란트에 비해 옥심 경화형 실란트의 곰팡이 저항성이 더 큼을 확인하였다. 또한, KS F ISO 21265 시험법에서는 50℃에서 4주간 침수 후 곰팡이 저항성을 평가하는 조건 도입을 통해 실란트의 장기적인 곰팡이 저항성 평가가 가능할 것으로 판단된다.

• Asian Pacific Journal of Cancer Prevention
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• 제16권12호
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• pp.5095-5099
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• 2015

Background: The statistical methods to analyze and predict the related dangerous factors of deep fungal infection in lung cancer patients were several, such as logic regression analysis, meta-analysis, multivariate Cox proportional hazards model analysis, retrospective analysis, and so on, but the results are inconsistent. Materials and Methods: A total of 696 patients with lung cancer were enrolled. The factors were compared employing Student's t-test or the Mann-Whitney test or the Chi-square test and variables that were significantly related to the presence of deep fungal infection selected as candidates for input into the final artificial neural network analysis (ANN) model. The receiver operating characteristic (ROC) and area under curve (AUC) were used to evaluate the performance of the artificial neural network (ANN) model and logistic regression (LR) model. Results: The prevalence of deep fungal infection from lung cancer in this entire study population was 32.04%(223/696), deep fungal infections occur in sputum specimens 44.05%(200/454). The ratio of candida albicans was 86.99% (194/223) in the total fungi. It was demonstrated that older (${\geq}65$ years), use of antibiotics, low serum albumin concentrations (${\leq}37.18g/L$), radiotherapy, surgery, low hemoglobin hyperlipidemia (${\leq}93.67g/L$), long time of hospitalization (${\geq}14$days) were apt to deep fungal infection and the ANN model consisted of the seven factors. The AUC of ANN model($0.829{\pm}0.019$)was higher than that of LR model ($0.756{\pm}0.021$). Conclusions: The artificial neural network model with variables consisting of age, use of antibiotics, serum albumin concentrations, received radiotherapy, received surgery, hemoglobin, time of hospitalization should be useful for predicting the deep fungal infection in lung cancer.