• Proceedings of the Korean Nutrition Society Conference
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• 2003.05a
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• pp.233.2-233.2
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• 2003

• The Korean Journal of Pesticide Science
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• v.11 no.2
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• pp.82-86
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• 2007

Methanol extract obtained from aerial parts of Vitis vinifero L. was successively fractionated with n-hexane, ethylacetate, n-butanol, and water. From ethylacetate fraction, an active compound was isolated through silica gel column chromatography and recrystallization, and was identified as Lup-20(29)-ene-3,28-diol on the basis of EI-MS data. The compound, at 100 mg $mL^{-1}$, inhibited the mycelial growth of Phytophthora capsici and Colletotrichum acutatum by 52.1 % and 40.8%, respectively.

• Microbiology and Biotechnology Letters
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• v.36 no.4
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• pp.268-275
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• 2008

In order to develop the multi-functional rhizobacteria that can exert positive effect on the growth of plants growing in the coastal sand dune located along East Coast of Korea, rhizospheral bacteria of 11 different plants from this area were isolated 1,330 rhizobacteria. Among these, 23 strains were able to produce auxin and had spectrum of antagonism toward various phytopathogenic microbes. To know the mechanism of this antifungal activity, these 23 strains were subjected to further analyses; 19 strains of these produced siderophore as determined by color reaction on CAS-blue plate, 4 strains produced antifungal cellulase as judged by color change on CMC-Congo red plate, 17 strains were able to utilized insoluble phosphate salts, also determined by clear zone formation on PVK medium. Identification of the strain was assigned to all 23 strains by l6s rDNA sequence analysed, and all were identified to be in the genus of Bacillus and Pseudomonas. One strain of these, denoted Pseudomonas fluorescens IB4-14, showed ACC deaminase activity which is known to be involved in the resistance of environmental stress such as salt and drought. Also, P. fluorescens IB4-l4 showed the germination stimulation and roots growth promoting activity on the in vivo assay of Lysimachia mauritiana Lam. (spoonleaf yellow loosestrife).

• Applied Biological Chemistry
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• v.40 no.6
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• pp.593-596
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• 1997

In the course of search antagonistic fungi from soil in green house, four kind of fungi (AF1, AF2, AF3, AF4) were isolated, which have activities against Phytophthora capsici, Botrytis cinera, Rhizoctonia solani, Pythium ultimum and Fusarium oxysporum. The AF2 was identified according to the morphological description of Aspergillus terreus. This antagonistic fungus inhibiting various plant pathogens was effective to reduce disease incidence of cucumber seedlings caused by mixed inoculum of Rhizoctonia solani, Pythium ultimum and Fusarium oxysporum. Antifungal compound I was isolated and purified by fresh chromatography from A. terreus. The $^1H$ and $^{13}C$ assignment of compound I was achieved from two-dimensional $^1H-^1H\;COSY$, HMQC, HMBC with the add of homonuclear and heteronuclear double resonance experiment. The compound I was identified butyrolactone I (${\alpha}$-oxo-${\beta}$-(p-hydroxyphenyl)-${\gamma}$-(p-hydroxy-m-3,3-dimethyl-allylbenzyl)-${\gamma}$-methoxycarbonyl-${\gamma}$-butyrolactone, $C_{24}H_{24}O_7$, M.W.=424).

• Korean Journal of Environmental Biology
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• v.27 no.4
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• pp.384-390
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• 2009

An antifungal antibiotic-producing bacterium was isolated from soil and identified as Bacillus sp. CJ-1. The culture supernatant was found to have a strong and stable antifungal activity against Colletotrichum gloeosporioides. Culture conditions for the maximum antifungal activity were examined. Glucose and yeast extract were selected as the best carbon and nitrogen sources. The optimum C/N ratio was 3. The optimum temperature and initial pH were determined as $35^{\circ}C$ and 6.0, respectively. Under these conditions, the production for the antibiotic was maximized at 72 hr at $35^{\circ}C$ after cultivation. Microscopic observation showed that the culture supernatant of Bacillus sp. CJ-1 had a strong inhibitory activity on the mycelial growth of the test strain at above $12.5\;{\mu}L\;mL^{-1}$ of concentration.

• Korean Journal of Microbiology
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• v.44 no.3
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• pp.258-263
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• 2008

Late blight, one of the most important disease in many agricultural crops, is caused by Phytophthora infestans. Fusarium wilt is a vascular disease of many plants caused by Fusarium oxysporum. Some bacteria isolated from rhizosphere were screened for their ability to inhibit the growth of F. oxysporum and P. infestans. Productions of siderophore, $\beta-1$,3-glucanase, hydrogen cyanide and chitinase by 4 isolated strains were examined. Among them, Bacillus sp. RFO41 most effectively inhibited the growth of F. oxysporum. The highest productions of siderophore and $\beta-l$,3-glucanase were shown in the culture of Bacillus sp. RFO41. Bacillus strain PS2 was most effective against P. infestans. PS2 showed the highest production of chitinase and hydrogen cyanide. A significant relationship was shown between the antagonistic effects of isolates against F. oxysporum and P. infestans and their production level of siderophore, $\beta-1$,3-glucanase, hydrogen cyanide, and chitinase.

• Korean Journal of Microbiology
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• v.49 no.2
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• pp.165-171
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• 2013

To isolate a novel antifungal compound, we obtained 571 kinds of endolichenic fungi from Lichen Bioresources Center and examined their antifungal abilities. Four fungi Stereocaulon sp. (1429), Stereocaulon sp. (1430), Cryptosporiopsis sp. (0156), and Graphis sp. (1245) showed high antifungal activity against Candida albicans when they grew in both liquid and solid media. We extracted the culture supernatants of these fungi with chloroform and then ethyl acetate. The chloroform fraction exhibited the highest anti-fungal activities when those fractions were examined for the growth inhibition of Candida albicans with disc diffusion method. To see information for the inhibitor present in chloroform fraction we employed GC-MS for the fractions of Stereocaulon sp. (1429). We found that hexamethylcyclotrisiloxane, decanoic acid, hexadecanonic acid-methyl ester, 14-octadecenoic acid-methyl ester, and octadecenoic acid-methyl ester were present more in chloroform fraction than in ethylacetate fraction. This indicates that those compounds could be possible antifungal candidates since antifungal activity of chloroform extract was two times higher than that of ethyl acetate extract.

• Microbiology and Biotechnology Letters
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• v.40 no.1
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• pp.23-29
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• 2012

To isolate a novel antifungal compound, we obtained 100 kinds of endolichenic fungi from Korean Lichen & Allied Bioresources Center and examined their antifungal capability. Three fungi Usnea rigidula (2326), Parmotrema pseudotinctorum (2202) and Myelochroa sp. (2292) showed high antifungal activity against Candida albicans when they grew in both liquid and solid media. We extracted the culture supernatants of these three fungi with chloroform and then with ethyl acetate. Chloroform fraction exhibited the highest antifungal activities when those fractions were examined for the growth inhibition of Candida albicans with disc diffusion method. The chloroform faction was on further analysis with $C_{18}$ column chromatography to see whether the inhibitors are already known or not. Two peak fractions were collected from 4-day culture extract for Usnea rigidula and from 6-day culture extract for Parmotrema pseudotinctorum on the HPLC. A peak fraction from chloroform extracts of 4-day culture filtrate of Parmotrema pseudotinctorum showed higher antifungal activities against C. albicans and C. glabrata than another peak fraction. It appears that the antifungal materials are relatively nonpolar as usnic acid often found in lichenic fungi.

• Microbiology and Biotechnology Letters
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• v.26 no.2
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• pp.122-129
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• 1998

It were reported that antifungal mechanism of Enterobacter cloacae is a volatile ammonia that produced by the strain in soil, and the production of ammonia is related to the bacterial urease activity. A powerful bacterium SH14 against soil-borne pathogen Fusarium solani, which cause root rot of many important crops, was selected from a ginseng pathogen suppressive soil. The strain SH14 was identified as Bacillus subtilis by cultural, biochemical, morphological method, and $API^{circledR}$ test. From several in vitro tests, the antifungal substance that is produced from B. subtilis SH14 was revealed as heat-stable and low-molecular weight antibiotic substance. In order to construct the multifunctional biocontrol agent, the urease gene of Bacillus pasteurii which can produce pathogenes-suppressive ammonia transferred into antifungal bacterium. First, a partial BamH I digestion fragment of plasmid pBU11 containing the alkalophilic B. pasteurii l1859 urease gene was inserted into the BamH I site of pEB203 and expressed in Escherichia coli JM109. The recombinant plasmid was designated as pGU366. The plasmid pGU366 containing urease gene was introduced into the B. subtilis SH14 with PEG-induced protoplast transformation (PIP) method. The urease gene was very stably expressed in the transformant of B. subtilis SH14. Also, the optimal conditions for transformation were established and the highest transformation frequency was obtained by treatment of lysozyme for 90 min, and then addition of 1.5 ${mu}g$/ml DNA and 40% PEG4000. From the in vitro antifungal test against F. solani, antifungal activity of B. subtilis SH14(pGu366) containing urease gene was much higher than that of the host strain. Genetical development of B. subtilis SH14 by transfer of urease gene can be responsible for enhanced biocontrol efficacy with its antibiotic action.

• Microbiology and Biotechnology Letters
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• v.10 no.2
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• pp.117-122
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• 1982

Streptomyces sp. No. 297 previously isolated from a soil sample collected in Mt. Soyo of Kyeongi Province, which produced strong antifungal substances t-cinnamamide and another unknown compound, was identified as Streptomyces griseorubiginosus var. soyoensis. The results of examinations in morphologial, physiological and cultural characteristics of the strain are presented.