• Proceedings of the Korean Society of Applied Entomolohy Conference
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• 2002.11a
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• pp.132-132
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• 2002

• Applied Biological Chemistry
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• v.40 no.5
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• pp.388-394
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• 1997

Extracellular protease (bassiasin I), from the culture filtrate of entomopathogenic fungus Beauveria bassiana ATCC7159, was successively purified by precipitation with ammonium sulfate followed by DEAE-Sephadex A-50, CM-cellulose and Hydroxyapatite column chromatography. A typical procedure provided 41-fold purification with 13.6% yield. The molecular weight of the purified pretense (bassiasin I) was found to be approximately 32,000 by SDS-PAGE. Isoelectric-focusing analysis of the enzyme showed a pI of 9.5. $NH_2-terminal$ sequence of the pretense showed homology with those of the fungal proteases. The enzyme has an optimal pH for activity at 10.5 and is stable over pH 5.0-11.0. The maximum activity of the enzyme was at $60-65^{\circ}C$, and approximately 20% activity remained at $60^{\circ}C$ after 120 min. The pretense was inhibited by phenylmethylsulfonyl fluoride (PMSF) and diisopropyl fluorophosphate (DIPF).

• Proceedings of the Korean Society of Applied Entomolohy Conference
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• 2001.05a
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• pp.98-98
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• 2001

• Proceedings of the Korean Society of Applied Entomolohy Conference
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• 2000.05a
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• pp.87-87
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• 2000

• The Korean Journal of Pesticide Science
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• v.18 no.4
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• pp.417-421
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• 2014

The beet armyworm, Spodoptera exigua is pest which is difficult to control. For eco-friendly beet armyworm managements, we isolated entomopathogenic fungi from soil samples by insect-bait method using Tenebrio molitor and conducted bioassay to larvae of beet armyworm. The result of bioassay, a selected strain Metarhizium anisopliae FT83 caused 100% mortality against first ~ third instar larva of S. exigua at $1{\times}10^8conidia/ml$ and medial lethal time ($LT_{50}$) were 0.5 days, 2.6 days and 2.5 days respectively. Mortality against fourth and fifth larvae were $83.3{\pm}6.2%$ and $86.0{\pm}5.7%$ and medial lethal time ($LT_{50}$) were 4.2 days and 3.6 days respectively. Mortality against pupae and eggs of S. exigua were 100%. M. anisopliae FT83 showed high virulence at all developmental stages of S. exigua.

• Applied Biological Chemistry
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• v.39 no.6
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• pp.449-454
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• 1996

We investigated the optimal condition for the production of extracellular pretense(a cuticle-degrading pretense) from entomopathogenic fungus Beauveria bassiana(ATCC7159) in liquid medium by adding of gelatin, bovine serum albumin(BSA), casein and polypeptone. The optimal induction medium for production of extracellular pretenses is composed of 0.5% polypeptone, trace elements and 50 mM potassium phosphate(pH 6.0). In this condition, the production of extracellular pretenses increased rapidly after the 24hrs, peaking at the third day and there was little inductive effect in culture broth more than pH 7.0. The pretenses were inhibited by phenyl methyl sulfonyl fluoride(PMSF). High activity of pretense was showed both range of pH 8.5 and 11.5 and also detected by three different portions of slice gel derived from non-denaturing isoelectricfocusing gel. At least three different extracellular pretenses are produced in optimal production medium when polypeptone is used as the sole carbon and nitrogen source.

• The Korean Journal of Mycology
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• v.26 no.3 s.86
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• pp.403-406
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• 1998

An entomophthoraceous fungus, Entomophthora planchoniana, was found in populations of the green peach aphid, Myzus persicae, at Kunsan city on June 2, 1998. Occurrence of this species has never been recorded in Korea. Microscopic observations of this fungus are described, and illustrated. Unique characters are that it forms unitunicate muscae-like conidia with $4{\sim}6$ nuclei, and is the only Entomophthora species which can attack aphids.

• The Korean Journal of Pesticide Science
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• v.19 no.2
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• pp.125-133
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• 2015

Entomopathogenic fungi have been studied to develop for biological control agents as an alternative to chemical control agents in insect pest management. Two Lepidopteran insects, Spodoptera exigua and Plutella xylostella, are serious insect pests infested various crops, but not effectively controlled by commercial chemical pesticides due to its high insecticide resistance. A fungal isolate was isolated from S. exigua larvae collected from green onion field in Andong, Korea. To identify the fungal isolate, 18srRNA sequence for internal transcribed spacer (ITS) and ${\beta}$-tubulin regions were sequenced. The ITS and ${\beta}$-tubulin sequence were highly matched to Beauveria bassiana and morphological characteristics also was fit to known B. bassiana. Finally, isolated fungus has identified as B. bassiana and named B. bassiana ANU1. The result of bioassay, median lethal concentrations were $2.7{\times}10^3$ and $0.9{\times}10^3conidia/ml$ and medial lethal times were 65.6 and 60.8 h to S. exigua and P. xylostella, respectively. B. bassiana ANU1 showed high pathogenicity to two insect pests from $20^{\circ}C$ to $30^{\circ}C$ at 50% relative humidity (RH) and more than 40% RH at $25^{\circ}C$ with $10^7conidia/ml$ of concentration.

• Korean Journal of Ecology and Environment
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• v.53 no.1
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• pp.73-79
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• 2020

Metarhizium anisopliae is one of the entomopathogenic fungi infecting Protaetia brevitarsis seulensis. Environmental conditions strongly affect the virulence of entomopathogenic fungus. To test the susceptibility of P. brevitarsis seulensis larvae to M. anisopliae, we determined level mortality rates under different rearing conditions: temperatures (20℃, 25℃, 30℃), relative humidities (RH; RH 40%, 50%, 60%, 70%), and water content in sawdust (40%, 50%, 60%). The mortality rate of larvae treated with 5×10⁶ conidia mL^-1 M. anisopliae was not significantly affected by rearing temperature, but was affected by low RH (40%) and low water content in sawdust (40%), both of which resulted in high mortality rates. Mortality rated among M. anisopliae-treated 1^st, 2^nd, and 3^rd instar larvae were highest in 1^st instar larvae.

• Journal of Sericultural and Entomological Science
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• v.38 no.2
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• pp.150-153
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• 1996

To develope a microbial pesticide for the control of agricultural and forestal pests in Korea, the mass culture system of entomopathogenic fungi was studied. Previously, we have developed the mass culture system which was adaptable for the culture of Beauveria bassiana. In this study, we determined the efficacy of this mass culture system for other entomopathogenic fungi, B. bassiana, Beauveria brongniartii, Metarhizium anisopliae, and Verticillium lecanni. To determine the efficacy of mass culture system, we examined the growth rate of entomopathogenic fungi in this system which was composed of 1st liquid media for growth of blastospore and 2nd pellet media for growth of conidia. As the result, we obtained that the blastopore numbers increased 103-104 times in liquid media at 72 hrs post inoculation. The results showed that this mass culture system for the growth of entomopathogenic fungi was effective.