• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2002년도 생물공학의 동향 (X)
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• pp.386-389
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• 2002

식물의 토양전염병을 유발하는 P. aphanidermatum 및 R. solani에 대한 길항력, 생장속도 및 표면장력 감소를 고려한 RPI (relative performance indices) 기법을 이용하여 90 여개 후보균 중 #16 길항균을 선정하였다. 선정된 Bacillus sp. #16은 16S rRNA 서열을 분석한 후 GenBank에서 비교한 결과 B. subtilis DSM10과 99% 유사성을 보였다. 또한 pot test 결과 오이 모잘록병에 대해 우수한 방제가를 보였다.

• Mycobiology
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• 제49권5호
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• pp.498-506
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• 2021

An endophytic fungus strain DYSJ3 was isolated from a stem of Aphanamixis grandifolia Blume, which was identified as Aspergillus versicolor based on the morphological characteristics, internal transcribed spacer (ITS) and calmodulin gene sequences analyses. A. versicolor DYSJ3 exhibited strong antagonistic activity against Colletotrichum musae, C. gloeosporioides and Fusarium oxysporum f. sp. cubense with the inhibition rates of 61.9, 51.2 and 55.3% respectively. The antifungal metabolites mainly existed in the mycelium of A. versicolor DYSJ3, and its mycelial crude extract (CE) had broad-spectrum antifungal activities against plant pathogenic fungi. The CE had a good thermal stability, and the inhibition rate of 100 mg/mL CE against C. musae was above 70.0% after disposing at 120 ℃ for 1 h. Five secondary metabolites were isolated from the CE and identified as averufanin, ergosterol peroxide, versicolorin B, averythrin and sterigmatocystin. Activity evaluation showed versicolorin B exhibited inhibitory effects on the mycelial growth and conidial germination of C. musae, and sterigmatocystin had a weak inhibitory effect on the mycelial growth of C. musae.

• Journal of Microbiology and Biotechnology
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• 제24권9호
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• pp.1149-1161
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• 2014

Cotton plants were sampled and ranked according to their resistance to Verticillium wilt. In total, 642 endophytic fungi isolates representing 27 genera were recovered from Gossypium hirsutum root, stem, and leaf tissues, but were not uniformly distributed. More endophytic fungi appeared in the leaf (391) compared with the root (140) and stem (111) sections. However, no significant difference in the abundance of isolated endophytes was found among resistant cotton varieties. Alternaria exhibited the highest colonization frequency (7.9%), followed by Acremonium (6.6%) and Penicillium (4.8%). Unlike tolerant varieties, resistant and susceptible ones had similar endophytic fungal population compositions. In three Verticillium-wilt-resistant cotton varieties, fungal endophytes from the genus Alternaria were most frequently isolated, followed by Gibberella and Penicillium. The maximum concentration of dominant endophytic fungi was observed in leaf tissues (0.1797). The evenness of stem tissue endophytic communities (0.702) was comparatively more uniform than the other two tissues. Eighty endophytic fungi selected from 27 genera were evaluated for their inhibition activity against highly virulent Verticillium dahliae isolate Vd080 in vitro. Thirty-nine isolates exhibited fungistasis against the pathogen at varying degrees. Seven species, having high growth inhibition rates (${\geq}75%$), exhibited strong antifungal activity against V. dahliae. The antifungal activity of both volatile and nonvolatile metabolites was also investigated. The nonvolatile substances produced by CEF-818 (Penicillium simplicissimum), CEF-325 (Fusarium solani), CEF-714 (Leptosphaeria sp.), and CEF-642 (Talaromyces flavus) completely inhibited V. dahliae growth. These findings deepen our understanding of cotton-endophyte interactions and provide a platform for screening G. hirsutum endophytes with biocontrol potential.

• 한국산림과학회지
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• 제87권3호
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• pp.429-444
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• 1998

Picea mariana 생장을 억제하는 Kalmia angustifolia에 영향을 주는 외생근균을 조사 선발하였다. 11개 외생근균중에서 19계통을 선발하여 Kalmia 잎침출물이 들어있는 배지에 P. mariana 치묘와 함께 근균을 접종하여 자라는 형태와 생장양상을 조사하였다. Kalmia 잎추출물을 첨가한 액체배지에서는 균사의 건중량을, 한천배지에서는 코로니의 직경을 측정한 결과 분리된 9개 균주에서는 현저하게 억제되었으나 나머지 10개 균주에서는 반대로 증가되거나 Kalmia의 영향이 나타나지 않았다. 배양배지의 pH가 3-4일 때는 생장을 억제 받는 근균도 있었으나 pH와 잎침출물을 조합한 조건하에서는 더욱 강하게 억제되었다. 분리된 13개 계통은 순수배양에서 Kalmia 잎침출물 25%와 함께 배양한 P. mariana에서 외생근균이 형성되었다. Paxillus involutus(NF4), Cenococcum geophilum(GB12), Laccaria laccata(GB23), E-strain(GB45)계통에서는 Kalmia 잎추출물 50%에서 배양한 결과 다른 계통보다 많은 외생근균이 형성이 되었다. 이러한 근균을 미리 접종한 P. mariana를 Kalmia 잎추출물과 같이 배양한 후 온실 안에서 4개월동안 Kalmia와 갈이 재배하였다. P. involutus, L. laccata 와 E-strain 미리 접종한 치묘에서는 많은 근균(흡수근외 77-91%)이 형성되었으나 C. geophilum를 미리 접종한 치묘에서는 근균이 비교적(흡수근의 32%) 적게 형성되었다. 외생균근이 대부분의 치묘에서 생겼음에도 불구하고 근균의 90% 이상이 접종근균에서 생겨났다. 근균의 지속적인 생장은 살아있는 Kalmia 식물개체에 영향을 받지 않았다. P. involutus, L.laccata와 E-strain과 같이 처리한 치묘 근균의 80% 이상과 C. geophilum을 처리한 치묘 근균의 53%가 접종된 균주의 영향을 받았다. 대조구에서는 토착균주에 의해 약 45%의 짧은 뿌리의 외생근균이 형성되었다. L. laccata와 C. geophidum는 Kalmia잎추출물과 같이 배양한 치묘의 근균행성을 촉진하였다. 균주를 접종한 경우 근균형성율은 pH5보다 pH4에서 4-15% 더 낮았으며 L. laccata를 접종한 경우 심하게 억제되었다. P. involtus에 접종한 치묘는 L. laccata를 E-strain를 접종한 치묘보다 줄기와 뿌리생장이 가장 높게 나타났다. P. involtus와 L. laccata를 접종한 치묘는 대조구의 치묘보다는 건중량이 많고 키가 훨씬 컸다. E-strain에 접종한 치묘는 대조구와 비교해서 1차 측근 수가 매우 작았으며 줄기 건중량은 매우 높게 나타났으나 다른 형질, 예를 들면 흡수근, 뿌리 건중량, 수고 등은 대조구와 크게 다르지 않았으나 C. geophilum에 접종한 치묘는 1차 측근수를 제외한 다른 생장 특징에서는 대조구와 크게 다르지 않았다.

• Mycobiology
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• 제43권4호
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• pp.435-443
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• 2015

Sixty-one endophytic fungus strains with different colony morphologies were isolated from the leaves, stems and roots of Tephrosia purpurea with colonization rates of 66.95%, 37.50%, and 26.92%, respectively. Based on internal transcribed spacer sequence analysis, 61 isolates were classified into 16 genera belonging to 3 classes under the phylum Ascomycota. Of the 61 isolates, 6 (9.84%) exhibited antifungal activity against one or more indicator plant pathogenic fungi according to the dual culture test. Isolate TPL25 had the broadest antifungal spectrum of activity, and isolate TPL35 was active against 5 plant pathogenic fungi. Furthermore, culture filtrates of TPL25 and TPL35 exhibited greater than 80% growth inhibition against Sclerotinia sclerotiorum. We conclude that the endophytic fungal strains TPL25 and TPL35 are promising sources of bioactive compounds.

• Mycobiology
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• 제35권2호
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• pp.72-75
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• 2007

Antifungal activity of 2-hydroxy 4,4'6'trimethoxy chalcone individually was tested against spore germination of ten fungi of different genera. Efficacy of the chemical was also tested against conidial germination and other growth parameters of Erysiphe pisi on excised pea leaves. 2-Hydroxy 4,4'6'trimethoxy chalcone inhibited spore germination at all the concentrations. Maximum inhibition was observed at 2000 ppm where more than 78 per cent inhibition of spore germination was observed in Ustilago cynodontis, Alternaria brassicicola, A. solani and Aspergillus flavus. It also reduced conidial germination of E. pisi significantly, when applied as pre-inoculation treatment.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.94.2-95
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• 2003

E. intermedium 60-2G possessing a strong ability to solubilize insoluble phosphate, has plant growth-promoting activity, induced systemic resistance activity against scab pathogen in cucumber, and antifungal activity against various phytopathogenic fungi. The phosphate solubilizing activity of 60-2G may be mainly accomplished by production of gluconic acid through a direct extracellular oxidation of glucose by glucose dehydrogenase that required a PQQ cofactor for its activation. A pqq gene cluster conferred Phosphate-solubilizing activity in E. coli DH5${\alpha}$ was cloned and sequenced. The 6,783 bP pqq sequence had six open reading frames (from A to F) and showed 50-95％ homology to pqq genes from other bacteria. The E. coli strain expressing the pqq genes solubilized phosphate from hydroxyapatite after a pH drop to 4.0, which paralleled in time the secretion of gluconic acid. To study the role of PQQ in biocontrol traits of E. intermedium, PQQ mutants of 60-2G were constructed by marker exchangee mutagenesis. The PQQ mutants of E. intermedium were lost activities of solubilizing phosphate, growth inhibition of phytopathogenic fungi, and plant growth promotion. These findings suggest that PQQ plays an important role, possibly activation of certain enzymes, in several beneficial bacterial traits of E. intermedium by as yet an unknown mechanism.

• Mycobiology
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• 제34권3호
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• pp.138-142
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• 2006

Soil cyanobacteria isolated from the rice paddy fields of 10 different locations across Korea were evaluated by agar plate diffusion test for antifungal activity. Aqueous, petroleum ether, and methanol extracts from one hundred and forty two cyanobacterial strains belonging to the 14 genera were examined for antifungal properties against seven phytopathogenic fungi causing diseases in hot pepper (Capsicum annuum L). Of total cyanobacteria, nine cyanobacteria (6.34%) exhibited antifungal effects. The nine cyanobacteria selected with positive antifungal activities were two species of Oscillatoria, two of Anabaena, three of Nostoc, one of Nodularia, and one of Calothrix. Alternaria alternata and Botrytis cinerea were inhibited by nine and eight species of cyanobacteria, respectively. Rhizopus stolonifer was suppressed by only methanol extract of Nostoc commune FK-103. In particular, Nostoc commune FK-103 and Oscillatoria tenuis FK-109 showed strong antifungal activities against Phytophthora capsici. Their antifungal activity at the late exponential growth phase is related to the growth temperature and not associated with the growth parameters such as cell biomass and $chlorophyll-{\alpha}$ concentration. The high inhibition levels of antibiotics were 22.5 and 31.8 mm for N. commune FK-103 and O. tenuis FK-109, respectively. The optimal temperature for antibiotic productivity was $35^{\circ}C$.

• 한국균학회지
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• 제41권2호
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• pp.118-126
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• 2013

The experiment was carried out to analyze the inhibition effect of plant pathogenic fungi and growth promotion activity induced by the bacterial strains isolated from peatmoss. Among the isolated bacterial strains, B10-2, B10-4, B10-5 and B10-6 which showed more than 30% inhibition rate against Botrytis cinerea and Rhizoctonia solani in vitro, were further analyzed in the greenhouse for the growth promotion activity on lettuce (Lactuca sativa), pak-choi (Brassica compestris L. ssp. chinensis) and Chinese cabbage (Brassica campestris L. ssp. pekinensis). The results showed the treatment of B10-4 on lettuce showed the highest growth promotion activity with the leaf area ($169.17cm^2$), fresh weight (leaf: 40.29 g, root: 8.80 g)and dry weight (leaf: 11.24 g, root: 4.17 g), which was about two folds as compared to control. On pak-choi, the growth promotion rate was the highest with the leaf area of $112.87cm^2$, leaf fresh weight of 60.70 g, root fresh weight of 3.37 g, leaf dry weight of 14.34 g, and root dry weight of 1.90 g. As a result of treatment of B10-13 on chinese cabbage, the growth promotion rate was the highest with the leaf area ($293.56cm^2$), fresh weight (leaf: 113.67 g, root: 2.40 g) and dry weight (leaf: 6.03 g, root: 0.53 g). The production of Indole Acetic Acid (IAA) and Indole-3-Butylic Acid (IBA) were also analyzed in these bacterial isolates. The IAA and IBA analyses were carried out in all bacterial isolates each day within the 5 days of incubation period. The highest production of IAA was observed with $112.57{\mu}g/mg$ protein in B10-4 after 3 days of incubation and IBA production was the highest in B10-2 with $58.71{\mu}g/mg$ protein after 2 days of incubation. Also, phosphate solubilizing activity was expressed significantly in B10-13 in comparison to that of other bacterial isolates. Bacterial identification showed that B10-2 was Bacillaceae bacterium and B10-5 was Bacillus cereus, B10-4 and B10-6 were Bacillus sp. and B-13 was Staphylococcus sp. by ITS sequence.

• Journal of the Korean Wood Science and Technology
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• 제38권6호
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• pp.579-586
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• 2010

목련과 식물의 활용도 제고를 위해 항산화제, 식품첨가제 개발에 필요한 항균 및 항산화 활성을 검정하였다. 우선 목련과 총 11종 식물의 수피, 잎, 목부, 꽃 및 열매의 에탄올 조추출물을 1,000 ${\mu}g/m{\ell}$로 조제하여 항진균 활성을 조사하였다. 그 결과 일본목련 수피가 백색부후균인 Trametes versicolor를 제외한 모든 공시균주에 대하여 50% 이상의 균사생장억제율을 나타내어 항균활성이 가장 높은 것으로 나타났다. 그 다음이 일본목련 목부로 탄저병균인 Glomerella cingulata와 목재부후균인 T. versicolor, Tyromyces palustris를 제외한 공시균주에 대하여 50% 이상의 균사생장억제율을 나타내었다. 수종별로는 일본목련이 가장 항균활성이 우수하여 수피, 잎, 목부 모두 항균활성이 있는 것으로 나타났으며 그 다음이 목련, 함박꽃나무 순이었다. 부위별로는 수피가 가장 활성이 우수하였으며 백목련, 자목련의 경우에는 다른 부위에 비해 꽃의 항균활성이 우수하였다. 또한, 프리라 디칼소거능을 측정하여 항산화활성을 검정한 결과에서는 100 ${\mu}g/m{\ell}$의 농도에서 태산목 수피와 잎이 70% 이상의 소거능을, 그리고 초령목 수피와 잎, 흑오미자 줄기 및 남오미자 줄기가 90% 이상의 소거능을 나타내었다. 특히, 흑오미자 줄기 및 남오미자 줄기는 10 ${\mu}g/m{\ell}$의 농도에서 각각 41.2%와 44.4%의 소거능을 나타내어 합성 항산화제인 butylated hydroxyanisole 및 천연항산화제인 ${\alpha}$-tocopherol과 동등한 항산화활성이 있는 것으로 밝혀졌다. 금후 흑오미자 및 남오미자 줄기와 같이 항산화활성 우수 시료는 활성물질 분리 및 구조 동정, 안전성 검정 등을 통하여 식품보존제 및 화장품 소재로 개발이 가능할 것으로 사료되었다.