• Journal of Microbiology and Biotechnology
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• v.17 no.7
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• pp.1217-1220
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• 2007

The saprophytic fungus Ulocladium atrum Preuss is a promising biological control agent for Botrytis cinerea in greenhouse- and field-grown crops. However, despite its known potent antifungal activity, no antifungal substance has yet been reported. In an effort to characterize the antifungal substance from U. atrum, we isolated an antibiotic peptide. Based on extensive spectroscopic analyses, its structure was established as a cyclopeptolide with a high portion of N-methylated amino acids, and its $^1H$ and $^{13}C$ chemical shifts were completely assigned based on extensive 1D and 2D NMR experiments. Compound 1 exhibited potent antifungal activity against the plant pathogenic fungus Botrytis cinerea and moderate activity against Alternaria alternate and Magnaporthe grisea.

• Journal of Applied Biological Chemistry
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• v.61 no.1
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• pp.69-73
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• 2018

Oak mushroom (Lentinus edodes) is cultivated by using oak logs and sawdust medium. Green mold (Trichoderma) infection on these media severely suppresses the growth of oak mushroom. Usages of antibiotics and chemicals are not generally allowed to control of green mold since the mushroom is a fresh food. Tolaasin and its analogues, peptide toxins secreted by Pseudomonas tolaasii, have the antifungal activity and they have been successful to control the green mold disease. When the green mold, Trichoderma harzianum H1, was cultured in the presence of these toxins, the growth of fungus was effectively suppressed. In sawdust media, when the bacterial culture supernatants were sprayed on the aerial hyphae of green molds, the fungal growth was completely suppressed. Particularly, the antifungal activity was greatly increased by the combined culture extracts of P. tolaasii 6264 and HK11 strains. Therefore, these bacterial strains and their peptide toxins were able to suppress the growth of green molds and these can be good candidates to prevent from Trichoderma disease in oak mushroom cultivation.

• Journal of Microbiology and Biotechnology
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• v.11 no.5
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• pp.798-803
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• 2001

Peptide synthetases produced from various microorganisms are multifunctional enzyme complexes and their substrates are recognized and activated by adenylation domains. To identify the substrate specificity of the peptide synthetase isolated from Bacillus subtilis 713, known to produce an antifungal peptide, two adenylation domains containing the minimal functional portion were expressed and purified. ATP-ppi exchange experiments and kinetic studies revealed that the two adenylation enzymes had a substrate specificity to $_{L}-lysine{\;}and{\;}_{L}-tryptophan$, respectively. In addition, based on a signature sequence comparison, the substrate of the third domain was predicted to be L-glutamic acid. These results suggest that this peptide synthetase is novel because there has been no previous report on a peptide synthetase that uses $_{L}-lysine,{\;}_{L}-tryptophan,{\;}and{\;}_{L}-glutamic$ acid as substrates in that order.

• Journal of Microbiology and Biotechnology
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• v.25 no.11
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• pp.1954-1959
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• 2015

Bacillus subtilis HM1 was isolated from the rhizosphere region of halophytes for its antifungal activity against Colletotrichum acutatum, the causative agent of anthracnose. Treatment of postharvest apples with the cell culture or with a cell-free culture supernatant reduced disease severity 80.7% and 69.4%, respectively. Both treatments also exhibited antifungal activity against various phytopathogenic fungi in vitro. The antifungal substances were purified and analyzed by acid precipitation, gel filtration, high-performance liquid chromatography, and matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). Three compounds were identified as fengycin, iturin, and surfactin. The MALDI-TOF/TOF mass spectrum revealed the presence of cyclized fengycin homologs A and B, which were distinguishable on the basis of the presence of either alanine or valine, respectively, at position 6 of the peptide sequence. In addition, the cyclized structure of fengycin was shown to play a critical role in antifungal activity.

• International Journal of Industrial Entomology and Biomaterials
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• v.17 no.1
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• pp.131-135
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• 2008

A cDNA encoding a defensin-like peptide (Protaetiamycine) from the larvae of a beetle, Protaetia brevitarsis was cloned. The DNAs encoded the deduced propeptide of 79 amino acid residues with the predicted molecular weight of 8.4 kDa and PI of 8.24. Overall amino acid sequence of this protein has 39% similarity to that of Rhodnius prolixus defensin, 43% similarity to that of Acalolepta luxuriosa defensin, and 72% similarity to that of Oryctes rhinoceros defensin, suggesting that this gene is an insect defensin. In an attempt to apply the anti-bacterial peptide to the development of therapeutic agents, a 12-mer peptide amidated at its C-terminus, ACAAHCLAIGRG-$NH_2$ (Ala55-Lys66-$NH_2$, 12Pbn) was synthesized. This peptide showed some antifungal activity against Candida albicans. To increase antifungal activity, six 9-mer peptides were synthesized by modifying amino acid sequences of 12Pbn fragment. Among these peptides, 9Pbm3-9Pbm6 exhibited strong activity compared with Cecropin B and mellitin.

• Journal of Microbiology and Biotechnology
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• v.20 no.8
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• pp.1185-1188
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• 2010

Previously, papiliocin was isolated from the swallowtail butterfly Papilio xuthus and its antimicrobial activity was suggested. In this study, the antifungal mechanism of papiliocin against Candida albicans was investigated. Confocal laser scanning microscopy (CLSM) and 1,6-diphenyl-1,3,5-hexatriene (DPH) fluorescence analysis indicated that papiliocin disturbed the fungal plasma membrane. Moreover, the assessment of the release of FITC-dextran (FD) from liposomes further demonstrated that the antifungal mechanism of papiliocin could have originated from the pore-forming action and that the radius of the pores was presumed to be anywhere from 2.3 to 3.3 nm.

• Journal of Microbiology and Biotechnology
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• v.28 no.11
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• pp.1771-1781
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• 2018

The emergence of multidrug-resistant microorganisms, as well as fungal infectious diseases that further threaten health, especially in immunodeficient populations, is a major global problem. The development of new antifungal agents in clinical trials is inferior to the incidence of drug resistance, and the available antifungal agents are restricted. Their mechanisms aim at certain characteristics of the fungus in order to avoid biological similarities with the host. Synthesis of the cell wall and ergosterol are mainly targeted in clinical use. The need for new approaches to antifungal therapeutic agents or development alternatives has increased. This review explores new perspectives on mechanisms to effectively combat fungal infections and effective antifungal activity. The clinical drug have a common feature that ultimately causes caspase-dependent cell death. The drugs-induced cell death pathway is associated with mitochondrial dysfunction, including mitochondrial membrane depolarization and cytochrome c release. This mechanism of action also reveals antimicrobial peptides, the primary effector molecules of innate systems, to highlight new alternatives. Furthermore, drug combination therapy is suggested as another strategy to combat fungal infection. The proposal for a new approach to antifungal agents is not only important from a basic scientific point of view, but will also assist in the selection of molecules for combination therapy.

• Microbiology and Biotechnology Letters
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• v.21 no.6
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• pp.564-569
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• 1993

AF-001A is a novel antifungal cyclic glyco-peptise isolated from Pseudomonas cepacia AF6008. AF-001A is a mixture of AF-011A1 and AF-001A2. Each compound contains glycine(1), serine(2), asparagine(1), 2,4-diaminobutyric acid(1), beta-hydroxytyrosine(1), xylose(1) and a methylene chain amino acid(1). Additionally, A1 contains one beta-hydroxyasparagine that is replaced with as asparagine in A2. AF-011A showed high in vitro antifungal activity against various animal and plant pathogenic fungi and caused no irritation on the skin of rabbits.

• Mycobiology
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• v.31 no.4
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• pp.248-250
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• 2003

Kojic acid was investigated for its antifungal activity against the human pathogenic fungi including Candida albicans, Cryptococcus neoformans and Trichophyton rubrum. For C. albicans, C. neoformans and T. rubrum, the MIC(minimum inhibitory concentration) of kojic acid was 640, 80 and 160 ${\mu}g/ml$, respectively. In C. neoformans, melanin-producing yeast, kojic acid-treated nonmelanized cell was more susceptible to magainin than melanized cell, suggesting melanin give a protective function against microbial peptide.

• Proceedings of the Korean Society of Sericultural Science Conference
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• 2003.04a
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• pp.76-76
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• 2003

Here we report an antifungal peptide isolation from G. mellonella larvae. The peptide shows a high degree of sequence homology to an insect defensin, named heliomicin, first reported in Lepidoptera. The peptide was purified by a three-step procedure consisting of acid extraction, gel permeation chromatography and reversed-phase HPLC. First the N-terminal amino acid sequence of the purified peptide was determined by automated Edman degradation. (omitted)