• 한국균학회소식:학술대회논문집
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• 한국균학회 2014년도 춘계학술대회 및 임시총회
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• pp.41-41
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• 2014

Pinewood nematode (PWN, Bursaphelenchus xylophilus) is a serious pathogenic worm that quickly dry pine trees to death. Recently, PWN has been devastating huge amounts of conifer trees in Korea. As a first step to explore the association and ecological roles of fungi in PWN life cycle in Korea, in this study we first isolated and indentified fungi from PWN-infested Korean pine and Japanese black pine wood sampled in Jinju, Sacheon, Pocheon, Chuncheon, Gwangju, and Hoengseong in Korea. A total of 144 fungal isolates were obtained from Japanese black pine wood and 264 fungal isolates from Korean pine wood. Their morphology and nucleotide sequences of the ITS rDNA and ♌-tubulin gene were examined for species identification. Ophiostoma ips, Botrytis anthophila, Penicillium sp., Hypocrea lixii, Trichoderma atroviride, O. galeiforme, Fusarium proliferatum were identified from Japanese black pine wood. Leptographium koreanum, L. pini-densiflorae, Ophiostoma ips, Penicillium raistrick, Trichoderma sp. were isolated from Korean pine wood. O. ips and L. koreanum were the major species on the two different PWN-infected pine tree. The cultivation of PWN on fungal mat of the identified species did some enhance PWN reproduction. The ambrosia beetle, Platypus koryoensis, is a serious pest of oak trees in Korea. In this study we investigated filamentous fungi present in the body of the beetle. Fourteen genera of filamentous fungi belonging to Ascomycota and Basidiomycota were isolated. All the obtained genera were isolated in the mitosporic state. The identified fungi were classified in 11 distinct orders including the Ascomycota (Eurotiales, Hypocreales, Microascales, Ophiostomatales, Pleosporales, and Sordiales) and Basidiomycota (Agaricales, Corticiales, Polyporales, and Russulales Xylariales). Within Ascomycota, 13 species were found. Meanwhile five species were found within Basidiomycota. The results showed the presence of diverse fungi in P. koryoensis. Among the isolated fungi, some were able to produce wood degrading enzymes. Further fungal isolation was performed with P. koryoensis infested Quercus mongolica trees sampled at Kumdan mountain in Hanam-Si, Gyeonggi province from June of 2009 to June of 2010. Penicillin spp. and Trichoderma spp. were the major species of mold fungi group. Pichia guilliermondii was the major species of mold yeast group. Raffaelea quercus-mongolicae was also isolated, but its isolation frequency was not high. Other species identified were Ambrosiella xylebori, Fusarium solani, Cryphonectria nitschke, Chaetomium globosum, and Gliocladium viride, Candida kashinagacola, C. maritima, C. vanderkliftii, Saccharomycopsis crataegensis.

• Journal of Ginseng Research
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• 제36권2호
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• pp.211-217
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• 2012

Endophytic fungi were isolated from various tissues (root, stem, petiole, leaf, and flower stalk) of 3- and 4-year-old ginseng plants (Panax ginseng Meyer) cultivated in Korea. The isolated endophytic fungi were identified based on the sequence analysis of the internal transcribed spacer (ITS), 1-5.8-ITS 2. A morphological characterization was also conducted using microscopic observations. According to the identification, 127 fungal isolates were assigned to 27 taxa. The genera of Phoma, Alternaria and Colletotrichum were the most frequent isolates, followed by Fusarium, Entrophospora and Xylaria. Although 19 of the 27 taxa were identified at the species level, the remainder were classified at the genus level (6 isolates), phylum level (Ascomycota, 1 isolate), and unknown fungal species (1 isolate). Endophytic fungi of 13 and 19 species were isolated from 3- and 4-year-old ginseng plants, respectively, and Phoma radicina and Fusarium solani were the most frequently isolated species colonizing the tissues of the 3- and 4-year-old ginseng plants, respectively. The colonization frequency (CF%) was dependant on the age and tissue examined: the CFs of the roots and stems in the 3-year-old ginseng were higher than the CF of tissues in the 4-year-old plants. In contrast, higher CFs were observed in the leaves and petioles of 4-year-old plants, and endophytic fungi in the flower stalks were only detected in the 4-year-old plants. In conclusion, we detected diverse endophytic fungi in ginseng plants, which were distributed differently depending on the age and tissue examined.

• Journal of Microbiology and Biotechnology
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• 제29권1호
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• pp.66-78
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• 2019

In this study, strain KNU17Pc1 was tested for its antifungal activity against Rhizoctonia solani AG-1(IA), which causes banded leaf and sheath blight (BLSB) of maize. KNU17Pc1 was tested further for its broad-spectrum antifungal activity and in vitro plant growth promoting (PGP) traits. In addition, the in vivo effects of KNU17Pc1 on reduction of BLSB severity and seedling growth promotion of two maize cultivars under greenhouse conditions were investigated. On the basis of multilocus sequence analysis (MLSA), KNU17Pc1 was confirmed as P. chlororaphis subsp. aurantiaca. The study revealed that KNU17Pc1 had strong in vitro antifungal activity and was effective toward all in vitro PGP traits except phosphate solubilization. In this study, for the first time, a strain of P. chlororaphis against Colletotrichum dematium, Colletotrichum gloeosporioides, Fusarium oxysporum f.sp. melonis, Fusarium subglutinans and Stemphylium lycopersici has been reported. Further biochemical studies showed that KNU17Pc1 was able to produce both types of phenazine derivatives, PCA and 2-OH-PCA. In addition, solid phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS) analysis identified 13 volatile organic compounds (VOCs) in the TSB culture of KNU17Pc1, 1-undecene being the most abundant volatile. Moreover, for the first time, Octamethylcyclotetrasiloxan (D4), dimethyl disulfide, 2-methyl-1,3-butadiene and 1-undecene were detected in P. chlororaphis. Furthermore, this study reported for the first time the effectiveness of P. chlororaphis to control BLSB of maize. Hence, further studies are necessary to test the effectiveness of KNU17Pc1 under different environmental conditions so that it can be exploited further for biocontrol and plant growth promotion.

• 한국버섯학회지
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• 제19권4호
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• pp.272-278
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• 2021

Bacillus velezensis HKB-1가 표고버섯 수확후배지 퇴비로부터 분리되었으며 고추역병균(Phythopthora capsici), 인삼모잘록병균(Rhizoctonia solani), 고추탄저병균(Collectotrichum coccodes) 및 시들음병(Fusarium oxysporium)의 균사체 성장을 70% 이상 억제하는 항 진균 활성을 보였다. B. velezensis HKB-1은 표고버섯 수확후배지 퇴비 물 추출물과 당밀 1% 첨가배지에서 다른 상업용 세균배지보다 10~100배 더 높은 세균증식률을 보였으며 고추 역병균의 균사체 생장을 90% 억제하였으며 고추생육 촉진효과 및 고추역병에 대하여 70% 이상의 방제효과가 있었다.

• Journal of Microbiology and Biotechnology
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• 제33권5호
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• pp.607-620
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• 2023

The biocontrol approach using beneficial microorganisms to control crop diseases is becoming an essential alternative to chemical fungicides. Therefore, new and efficient biocontrol agents (BCA) are needed. In this study, a rhizospheric actinomycete isolate showed unique and promising antagonistic activity against three of the most common phytopathogenic fungi, Fusarium oxysporum MH105, Rhizoctonia solani To18, and Alternaria brassicicola CBS107. Identification of the antagonistic strain, which was performed according to spore morphology and cell wall chemotype, suggested that it belongs to the Nocardiopsaceae. Furthermore, cultural, physiological, and biochemical characteristics, together with phylogenetic analysis of the 16S rRNA gene (OP869859.1), indicated the identity of this strain to Nocardiopsis alba. The cell-free filtrate (CFF) of the strain was evaluated for its antifungal potency, and the resultant inhibition zone diameters ranged from 17.0 ± 0.92 to 19.5 ± 0.28 mm for the tested fungal species. Additionally, the CFF was evaluated in vitro to control Fusarium wilt disease in Vicia faba using the spraying method under greenhouse conditions, and the results showed marked differences in virulence between the control and treatment plants, indicating the biocontrol efficacy of this actinomycete. A promising plant-growth promoting (PGP) ability in seed germination and seedling growth of V. faba was also recorded in vitro for the CFF, which displayed PGP traits of phosphate solubilization (48 mg/100 ml) as well as production of indole acetic acid (34 ㎍/ml) and ammonia (20 ㎍/ml). This study provided scientific validation that the new rhizobacterium Nocardiopsis alba strain BH35 could be further utilized in bioformulation and possesses biocontrol and plant growth-promoting capabilities.

• 한국토양비료학회지
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• 제26권4호
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• pp.271-277
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• 1993

고추와 옥수수의 근권(根圈)에서 분리(分離)하여 작물의 병원성(病原性) 사상균(絲狀菌)인 R. solani, F. oxysprum, F. solani에 대한 생육(生育) 저해력(沮害力)이 강한 B. subtilis B-4와 B-5를 분리(分離), 동정(同定)하였다. B. subtilis B-5 균주(菌株)에 plasmid pCPP4를 삽입하여 약제(藥劑) 내성(耐性)의 표식균주(標識菌株)를 조제하고 선발균주(選拔菌株)와 표식균주(標識菌株)의 생리적 특성을 비교 검토하였으며. 이들이 배추와 참깨의 생장(生長)과 토양(土壤) 미생물상(微生物相)에 미치는 영향(影響)을 조사(調査)한 결과(結果)를 요약(要約)하면 다음과 같다 1. B. subtilis B-4와 B-5 균주(菌株)는 탄소원(炭素源)으로 glucose, arabinose, surcose, fructose, lactuse, mannitol, sorbitol 등을 이용하였고 neomycine 저항성 표식균주(漂識菌株)도 선발균주(選拔菌株)와 동일한 성질(性質)을 나타내었다. 2. 길항균(拮抗菌)의 접종(接種)에 따른 배추의 발아율(發芽率)은 일반적으로 petri dish 접종시(接種時)보다 연작토양(連作土壤)에 접종(接種)했을 때 R. solani 혼합접종구(混合接種區)에서 대조구(對照區)에 비하여 모두 20~25%의 높은 발아율(發芽率) 증가(增加)를 나타냈으며, F. oxy-sporum 혼합접종구(混合接種區)에서는 대조구(對照區)에 비하여 선발균주(選拔菌株)인 B-4, B-5 균주(菌株)의 접종구(接種區)가 14% 이상(以上)의 증가(增加)를 보였다. 3. 참깨의 발아(發芽)에 미치는 영향(影響)은 petri dish 접종(接種)에서 표식균주(標識菌株) B-5NEOr(94.1%), 토양접종(土壤接種)에서 B-5(97.1%)가 가장 우수(優秀)하였고, 선발균주(選拔菌株)인 B-4, B-5 길항균(拮抗菌)의 접종구(接種區)가 대조구(對照區)에 비해 10% 이상(以上)으로 발아율(發芽率)이 향상(向上)되었다. 일반적으로 표식균주(漂識菌株)에 비해 선발균주(選拔菌株)가, 그리고 petri dish보다는 토양(土壤) 접종시(接種時)에 발아(發芽)가 향상(向上)되었다. 4. 선발균주(選拔菌株)와 표식균주(標識菌株)의 초기생육(初期生育) 촉진효과(促進效果)는 배추에서 B-5균주(菌株)와 병원성(病源性) 사상균(絲狀菌)인 F. oxysporum을 혼합(混合) 접종(接種)한 처리구(處理區)가 대조구(對照區)에 비해 신선중(新鮮重)이 66%, 초장(草長)이 23% 증가(增加)하여 우수한 생육(生育)을 나타냈으며, 참깨에서 B-5NEOr과 F. oxysporum의 혼합처리구(混合處理區)와 B-5와 R. solani의 혼합처리구(混合處理區)에서 생체중(生體重)이 대조구(對照區)에 비해 2배 이상(以上)으로 높은 향상(向上)을 보였다. 5. 표식균주(標識菌株)를 배추와 참깨의 근권(根圈)에 $1.1{\times}10^8CFU/g$ dry soil로 접종(接種)한 결과 표식균주(標識菌株)는 4주후 $10^5{\sim}10^6$으로 경시적인 감소(減少)를 보였으며, Pseudomonas속균은 $10^5$수준으로 일정하게 유지(維持)되는 경향(傾向)이었다. 그러나 사상균(絲狀菌)은 최초 $10^8$에서 4주후 $10^3$수준으로 급소히 감소(減少)하여 B. subtilis 접종(接種)으로 사상균(絲狀菌)의 생육(生育)이 현저히 저해(沮害)되는 것으로 나타났다.

• The Plant Pathology Journal
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• 제31권3호
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• pp.278-289
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• 2015

Indigenous strains of Trichoderma species isolated from rhizosphere soils of Tea gardens of Assam, north eastern state of India were assessed for in vitro antagonism against two important tea fungal pathogens namely Pestalotia theae and Fusarium solani. A potent antagonist against both tea pathogenic fungi, designated as SDRLIN1, was selected and identified as Trichoderma viride. The strain also showed substantial antifungal activity against five standard phytopathogenic fungi. Culture filtrate collected from stationary growth phase of the antagonist demonstrated a significantly higher degree of inhibitory activity against all the test fungi, demonstrating the presence of an optimal blend of extracellular antifungal metabolites. Moreover, quantitative enzyme assay of exponential and stationary culture filtrates revealed that the activity of cellulase, ${\beta}$-1,3-glucanase, pectinase, and amylase was highest in the exponential phase, whereas the activity of proteases and chitinase was noted highest in the stationary phase. Morphological changes such as hyphal swelling and distortion were also observed in the fungal pathogen grown on potato dextrose agar containing stationary phase culture filtrate. Moreover, the antifungal activity of the filtrate was significantly reduced but not entirely after heat or proteinase K treatment, demonstrating substantial role of certain unknown thermostable antifungal compound(s) in the inhibitory activity.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.102.1-102
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• 2003

A bacterial strain YC4963 with antifungal activity against Colletotrichum orbiculare, a causal organism of cucumber anthracnose was isolated from the rhizosphere soil of Siegesbeckia pubescens (Siegesbeckia pubescens Makino；Family：Compositae) in Korea. Based on physiological and biochemical characteristics and 16S ribosomal DNA sequence analysis, the bacterial strain was identified as Pseudomonu aureofaciens. The bacteria also inhibited mycelial growth of several plant fungal pathogens such as Botrytis cinerea, Fusarium oxysporum and Rhizoctonia solani on PDA and 0.1 TSA media. The antibiotic activity was found from the culture filtrate of TSB(tryptic soy broth) and its active compounds were quantitatively bound to XAD adsorber resin. The antibiotic spectrum was broad and growth of C. orbiculare and F. oxysporum, B. cinerea were inhibited at very low concentration. The chemical data from various chromatographic procedures showed that active fraction consisted of at least two phenazine derivatives. However, the metabolites had no inhibitory effect on Pythium ultimum which was reported to be sensitive to phenazine antibiotics. The compounds responsible for the activity are now under investigation.

• Applied Biological Chemistry
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• 제41권8호
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• pp.600-604
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• 1998

Methanol extracts from 53 species of oriental medicinal plants in 34 families were tested for their fungicidal activities against Pyricularia grisea, Rhizoctonia solani, Phytophthora capsici, Phytophthora infestans, Collectotrichum dematium, Botryospaeria dothidea, Fusarium oxysporum f. sp. cucumerinum, Botrytis cinerea, Puccinia recondita, and Erysiphe graminis. In in vitro study using impregnated paper disc method, the efficacy varied with both plant pathogen and plant species tested. Methanol extracts of Asarum sieboldii roots, Sinomenium acutum roots, Pinus densiflora leaves, Rheum undulatum root barks, Coptis japonica roots, and Phellodendron amurense barks showed potent fungicidal activities against the various pathogens when treated with 10 mg/disc. In a whole plant test, methanol extracts of P. densiflora leaves and roots and C. japonica roots were highly effective against a variety of plant pathogens. As a naturally occurring fungicide, P. densiflora- and C. japonica-derived materials could be useful as new fungicidal products against various plant diseases induced by plant pathogenic fungi.

• The Plant Pathology Journal
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• 제16권4호
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• pp.189-199
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• 2000

To search for the antifungal substances, various actino-mycete isolates were obtained from various soils of Korea using plate dilution method on the humic acid vitamin agar plates. In the screening procedures using a dual culture method, 32 actionomycete isolates were selected, which showed the inhibitory activity against mycelial growth of plant pathogenic fungi Altirnaria mali, Colletotrichum gloeosporides, Fusarium oxysporum f.sp. cucumerinum, Magnaporthe grisea, Phytophthora capsici, and Rhizoctonia solani. Bioassay of the crude extracts from culture filtrates and mycelial mets revealed that 12 antagonistic actionomycetes produced highly active antifungal substances. Actinomycete strain S5-55 which showed the substantial antifungal activity against the tested fungi was selected for production of the antifungal substances. Based on the cytochemical and morphological characteristics, strain S5-55 was identified as a Streptomyces species. The results of the numerical identification using the TAXON program confirmed that Streptomyces strain S5-55 was identical with Streptomyces humidus including in TAXON major cluster 19. The production of antifungal substance was most favorable when S. humidus strain S5-55 was cultivated for 10 dats on soluble starch broth supplemented with $K_2$HPO$_4$. The antifungal substances active against the plant pathogenic fungi P. capsici and M. grisea were partially purified using $\textrm{C}_{18}$ reversed-phase column chromatography.