• Fisheries and Aquatic Sciences
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• v.17 no.2
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• pp.209-214
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• 2014

With the continuing demand for new solutions in the development of effective and safe candidiasis therapies, we investigated the efficacy of an antifungal agent from the marine brown alga Eisenia bicyclis. The methanolic extract of E. bicyclis evinced potential antifungal activity against Candida species. The ethyl acetate (EtOAc)-soluble extract from E. bicyclis demonstrated the strongest antifungal activity against Candida species among five solvent-soluble extracts. Indeed, the EtOAc-soluble extract showed minimum inhibitory concentrations (MICs) ranging from 4 to 8 mg/mL. Furthermore, the EtOAc-soluble extract considerably reversed high-level fluconazole resistance of Candida species. The MIC values of fluconazole against Candida species decreased substantially (from 64 to $4{\mu}g/mL$) in combination with the MIC of the EtOAc-soluble extract (4 mg/mL). The fractional inhibitory concentration indices of fluconazole ranged from 0.531 to 0.625 in combination with 4, 2, or 1 mg/mL of the EtOAc-soluble extract against Candida isolates, indicating that these combinations exert a marked synergistic effect against Candida isolates. These findings imply that compounds derived from E. bicyclis can be a potential source of natural antifungal agents against Candida species.

• Journal of Forest and Environmental Science
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• v.34 no.5
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• pp.395-404
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• 2018

Since the mass mortality of Quercus mongolica has been first reported in Gyeonggi province at 2004, the disease spread rapidly over Korean peninsula annually. Ambrosia beetle (Platypus koryoensis) was known as the insect vector of oak wilt fungus, Raffaelea quercus-mongolicae, and control methods of the disease had mainly been focused on eradication of insect vector. However, for the efficient management of the disease, combined control methods for both of the pathogenic fungus and insect vector are strongly required. As one of the efforts to suppress the pathogenic fungus, antifungal activities of Streptomyces isolated from oak forest soil were assayed in this study. Optimum culture condition for the selected isolates was also studied, As a result, Streptomyces blastmyceticus cultured in PDB (Potato Dextrose Broth) at $25^{\circ}C$ for 1 week showed the strongest antifungal activity against oak wilt fungus. Mycelial growth inhibition rates (MGIRs) of Streptomyces isolates were compared on culture media supplemented with heated and unheated culture filtrates of S. blastmyceticus. MGIRs on culture media with unheated culture filtrates were generally higher than those on culture media with heated culture filtrates. Antagonistic mechanism to get involved in the inhibition of hyphal growth and spore formation of the pathogen is due to the antifungal metabolites produced by Streptomyces. This study will provide the fundamental information in developing biocontrol agents for the environment-friendly management of oak wilt disease.

• KSBB Journal
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• v.18 no.6
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• pp.490-494
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• 2003

For the production of antifungal compound, strain B-1 was used as a strong producing strain among bacteria isolated from various soil samples. The optimum medium for the production of antifungal compound was PDB (potato starch 0.4%, dextrose 2％, pH5.1). The optimum conditions for the production of antifungal compound didn't affect on the carbon and nitrogen sources. The produced compound showed broad antimicrobial activity to the tested strains such as five fungi and four bacteria. The optimum pH and temperature of the production antifungal compound were pH 5.0 and 28$^{\circ}C$, respectively. Ether extrct (1$\mu\textrm{g}$/${\mu}\ell$) of culture broth was confirmed inhibitory zone by the thin layer chromatography and plate assay. The antimicrobial compound was unstabled after heat (121$^{\circ}C$) trsatment. Strain B-1 was mass cultured in a 5-liter tormentor, containing 3 liters of PDB medium at 28$^{\circ}C$, pH 5.0, 120 (pm with aeration (1L/min).

• Journal of Life Science
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• v.19 no.11
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• pp.1672-1678
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• 2009

The purified antifungal substances produced by Bacillus amyloliquefaciens IUB158-03 was positive to ninhydrin but negative to aniline, suggesting that the antifungal substance could be a peptide. FAB-MS, UV adsorption spectrum, and amino acid composition analysis revealed that the molecular weight of the antifungal substance was 1042 and that maximal adsorption was at 220 nm and 277 nm. The antifungal substance was composed of $Asn_3$, $Gln_2$, $Ser_1$, $Gly_1$, and $Tyr_1$. The composition and structural characteristics of antifungal substance were analysed by $^1H$-NMR spectrum, $^1H$-COSY, HMQC, which revealed that the compound belongs to the iturin A family. Temperature and pH had little effect on the stability of the antifungal substance in the ranges of $-70{\sim}121^{\circ}C$ and pH 6.0~10.0, respectively. It showed strong antibiotic activity against fungi. An in vitro cytotoxicity test using NIH3T3 cell showed that the antifungal substance does not have cytotoxicity. The number of circulating leukocytes and the hematobiological analysis of the mice administered with the antifungal substances was similar to those of the control group, indicating no cytotoxicity in vivo. Therefore, the antifungal substances extracted from culture broth of Bacillus amyloliquefaciens IUB158-03 have future potential as biocontrol agents against plant diseases caused by fungi.

• Journal of Korean Neurosurgical Society
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• v.49 no.3
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• pp.186-189
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• 2011

In recent years the immunocompromised population has increased rapidly to include people with acquired immune deficiency syndrome (AIDS), drug abusers, and transplant patients. Accordingly, the incidence of intracranial fungal infection has increased. Our institution experienced 2 cases of internal carotid artery (ICA) occlusion due to invasion of the cavernous sinus by an intracranial fungal infection. The first case was a 60-year-old man who presented with headache, eye pain, conjunctival injection, right-sided diplopia, and blurred vision. Infected tissues within the frontal and ethmoid sinuses were removed via bifrontal craniotomy and endoscopic sinus surgery through the Caldwell Luc approach. The second case was a 63-year-old woman who developed right-sided facial pain after a tooth extraction. The infection was not controlled despite continuous use of antifungal agents, resulting in death from sepsis. We believe that when intracranial fungal infection is suspected in a patient with orbital symptoms and a focal neurologic deficit, immediate angiographic investigation of possible ICA occlusion is warranted. Aggressive treatment with antifungal agents is the only way to improve prognosis.

• Mycobiology
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• v.46 no.2
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• pp.85-91
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• 2018

Endophytic fungi strains (n = 81) were isolated from the leaves, barks, and fruits of Camellia oleifera from Hunan province (China) to delineate their species composition and potential as biological control agents of C. oleifera anthracnose. The fungi were identified by morphological and phylogenetic analyses. Fungal colonization rates of the leaves, barks, and fruits were 58.02, 27.16, and 14.81%, respectively. The isolates were identified as 14 genera, belonging to two subdivisions, Deuteromycotina and Ascomycotina; 87.65% of all isolates belonged to Deuteromycotina. The dominant species, occurring with a high relative frequency, were Pestalotiopsis sp. (14.81%), Penicillium sp. (14.81%), and Fusarium sp. (12.35%). The Simpson's and Shannon's diversity indices revealed the highest species diversity in the leaves, followed by the barks and fruits. The similarity index for the leaves versus barks comparison was the highest, indicating that the number of endophytic fungal species shared by the leaves and barks was higher than barks and fruits or leaves and fruits. Based on the results of dual culture experiments, only five strains exhibited antifungal activity against C. oleifera anthracnose pathogen, with isolate ty-64 (Oidium sp.) generating the broadest inhibition zones. Our results indicate that the endophytes associated with C. oleifera could be employed as natural agents controlling C. oleifera anthracnose.

• Korean Journal of Food Science and Technology
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• v.32 no.6
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• pp.1258-1265
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• 2000

In oder to acquire microbial agents that can be utilized for control of aflatoxin produced by Aspergillus. flavus and Asp. parasiticus, antifungal bacteria were isolated. Antifungal bacteria was identified as Bacillus spp. based on morphology and physico-biochemical characteristics. Amount of aflatoxin $B_1$ from Doenjang(soybean paste) prepared with Asp. flavus, Asp. parasiticus, antifungal bacteria(Bacillus sp.), or mixture of Asp. flavus and Asp. parasiticus was 27.2 ppb, 30.3 ppb, 3.4 ppb, and 3.7 ppb, respectively. Aflatoxin $B_1$ was not detected from Doenjang(control) and Doenjang prepared with antifungal bacteria. Content and compositions of free sugars, fatty acid, organic acid and free amino acid in Doenjang prepared with Asp. flavus and Asp. parasiticus, antifungal bacteria and mixture of Asp. flavus and Asp. parasiticus were not significantly different. For volatile flavor compounds of Doenjang prepared with antifungal bacteria, 2-pentyl furan and butanoic acid were disappeared or reduced, while octadecene compounds were produced. However, those of Doenjang prepared with Asp. flavus or Asp. parasiticus and Doenjang(control) were not significantly different. These results suggested that the antifungal bacteria(Bacillus sp.) inhibited production of aflatoxin and that antifungal bacteria did not effect the quality of Doenjang.

• Korean Journal of Microbiology
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• v.49 no.1
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• pp.17-23
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• 2013

Candida biofilms are organized microbial communities growing on the surfaces of host tissues or indwelling medical devices, and the biofilms show enhanced resistance against the conventional antifungal agents. The roots of Coptidis chinensis have been widely used for medicinal purposes in East Asia. The present study was aimed to assess the effect of C. chinensis aqueous extract upon preformed biofilms of 10 clinical Candida albicans isolates and the antifungal activities which contribute to inhibit the C. albicans biofilm formation. Its effect on preformed biofilms was judged using XTT [2,3-Bis-(2-Methoxy-4-Nitro-5-Sulfophenyl)-2H-Tetrazolium-5-Carboxanilide)] reduction assay, and metabolic activity of all tested strains was reduced significantly ($57.3{\pm}14.7%$) at $98{\mu}g/ml$ of the C. chinensis extract. The extract damaged the cell membrane of C. albicans which was analyzed by fluorescein diacetate and propidium iodide staining. The anticandidal activity was fungicidal, and the extract obstructed the adhesion of C. albicans biofilms to polystyrene surfaces, arrested C. albicans cells at $G_o/G_1$ as well, and reduced the growth of biofilms or budding yeasts finally. The data suggest that C. chinensis has multiple antifungal effects on target fungi resulting in preventing the formation of biofilms. Therefore, C. chinensis holds great promise for exploring antifungal agents from natural products in treating and eliminating biofilm-associated Candida infection.

• The Korean Journal of Pesticide Science
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• v.10 no.3
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• pp.201-209
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• 2006

Antifungal activities of 43 different plant oils were evaluated against different phytopathogenic fungi. Thyme oil showed highest antifungal activity among the tested oils. The major of thyme oil were found to be thymol, carvacrol, bomeol, p-cymene and linalool. Thymol and carvacrol were found to be responsible for thyme's antifungal activity. The spore germination assay was conducted on Alternaria mail and Botrytis cinerea. Thymol and carvacrol strongly inhibited spore germination in the fungi test. In addition, thymol and carvacrol showed a curative effectiveness to gray mold disease on cucumber crop. The antifungal activities of alkylphenol and alkylaniline compounds, which has similar molecular structure to that of thymol or cavacrol, were also tested. It was found that alkylphenol compounds also show higher inhibition to spore germination. Thus, thymol, carvacrol and alkylphenol compounds can be used an potent antifungal agents.

• Fisheries and Aquatic Sciences
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• v.12 no.1
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• pp.29-34
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• 2009

Fifty seven species of common seaweed from the coast of Korea were screened for antifungal activity against Malassezia species. Seaweeds as a source of bioactive compounds are able to produce a great variety of secondary metabolites with different activities. There are numerous reports on the biological activities of seaweeds against human pathogens, fungi, and yeasts, but only few contain data regarding inhibitory effects against Malassezia sp., a major cause of dandruff and seborrheic dermatitis. To help address this paucity of information, this work was carried out to examine the antifungal effects of seaweed extracts against M. furfur and M. restricta. Of the fifty seven species of marine algae screened for their potential antifungal activity, only 17 species (29.8%) exhibited inhibitory activity. In agar disc diffusion method, the ether extracts of Corallina pilulifera, Enteromorpha linza, Laminaria japonica, Symphyocladia latiuscula and Ulva sp. showed strong antifungal activity. To identify major constituents in seaweed extracts, four selected extracts were analyzed on' a GC-MS equipped with a flame ionization detector, and compared to spectral data from databases WILEY229.LIB and NIST107.LIB. Most constituents in seaweed extracts are fatty acid-related compounds. When we evaluated any acute toxicity, the ether extracts of the selected four species were not toxic in mice. According to these results, it can be suggested that these seaweed extracts are valuable for the development of therapeutic agents in treating dandruff and seborrheic dermatitis. Further investigations to determine its bioactive compound(s) are currently in progress.