• Journal of Sericultural and Entomological Science
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• v.37 no.2
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• pp.172-175
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• 1995

To develope a liquid culture media for the mass culture of Beauveria bassiana blastospore, wheat bran and soybean cake were selected as a carbon and nitrogen source, respectively. The composition and final concentration of wheat bran and soybean cake in liquid culture media were determined by the growth of B. bassiana blastospore. The results showed that the growth of B. bassiana blastospore was effective in the rate of 3 wheat bran: 2 soybean cake and in 5% of final concentration of the liquid culture media, suggesting that the liquid culture media using wheat bran and soybean cake are available.

• Mycobiology
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• v.37 no.3
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• pp.218-224
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• 2009

The principal objective of this study was to determine the optimal liquid culture conditions in shake flasks for maximal sporulation of Beauveria bassiana. The optimal initial pH for the spore production of B. bassiana using Potato Dextrose Broth was 5.2. The screening in shake flasks of carbon and nitrogen sources resulted in the identification of an optimal medium based on 3% sucrose and 1% casamino acid, with a C : N ratio of 22 : 4. Using this medium, a production level of $5.65{\times}10^7$ spores per ml was obtained after 5 days of culture. Using 3% corn meal, 2% corn steep powder, and 2% rice bran, the maximum spore concentration of $8.54{\times}10^8$/ml was achieved 8 days after inoculation at $25^{\circ}C$ in a rotary shaking incubator operated at 200 rpm. This represents a yield gain of approximately 2.89 times that of pre-optimization.

• The Korean Journal of Mycology
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• v.6 no.1
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• pp.21-27
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• 1978

The growing behavior of Candida albicans in various concentration of glucose and corticosteroid media was studied with the method of modified hanging slide culture. The strains of Candida albicans used in this study were obtained from vaginal swab from outpatients and were isolated from cultured colonies on Sabouraud's glucose agar media. To detect the budding rate of blastospore, the diluted suspension of Candida albicans in normal saline were inoculated into various concentration of glucose (Gl, G2, G3, G4), corticosteroid (S1, S2, S3, S4) and corticosteroid with 10% pepton broth (D1, D2, D3, D4) respectively and cultured at room temperature $(22{\sim}25^{\circ}C)$. The number of budding of blastospore were counted under the high power field of light microscope (400X) at specific time interval, e.g, 1, 2, 3, 6, 9, 12, 18, and 24 hours after inoculation. The results are as following: 1. The most effective budding rate was seen in G4 media (1.25% glucose) in 18 hours aft inoculation (89%). 2. The budding rate in Sabouraud's glucose broth with various concentration of dexamethasone added, was not significantly different from that of simple Sabouraud's glucose broth within 18 hours after inoculation, but there was statistically. significant difference in two budding rate at 24 hours observation. 3. The budding rate in 10% pepton broth media with various concentration of dexamethasone was almost same budding rate in control group, which is normal saline and 10% pepton broth, except on 2 and 24 hours results.

• 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.

• International Journal of Industrial Entomology and Biomaterials
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• v.17 no.2
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• pp.181-187
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• 2008

An entomopathogenic fungus, Paecilomyces fumosoroceus SFP-198 was isolated in Kyungbuk province, Korea and screened out for the control of Trialeurodes vaporariorum nymphs. It showed 72.5% efficacy against second instars of T. vaporariorum nymphs at 6 days after treatment in the laboratory. To select an active ingredient for the mass production and the formulation, SFP-198 culture products were compared based on their insecticidal activities against T. vaporariorum nymphs. Among them, conidia and blastospores showed much higher insecticidal activity than supernatants. Furthermore, SFP-198 conidia were more heat-resistant than blastospores, and also powder form of conidia was more stable than their suspension form. SFP-198 conidia showed high pathogenicity on not only T. vaporariorum but also Tetranychus urticae in the glasshouse. This result suggested that SFP-198 conidia can be used as a multi-targeting biological control agent against sucking agri- cultural pests, such as whiteflies and mites.

• International Journal of Industrial Entomology and Biomaterials
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• v.35 no.1
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• pp.58-62
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• 2017

The two-spotted spider mite (Tetranychus urticae) has sustained damage on more than 200 host plants worldwide. Many farmers have relied on chemical acaricides to control mite, but the abuse of acaricides has caused serious resistance to mite. To overcome this problem, microbial control using entomopathogenic fungi have been studied. Entomopathogenic fungi have been an important role against the control of pest, and most of their culture products have been demonstrated to have virulence against pest population. In this study, we evaluated and compared the virulence of culture filtrates, aerial conidia and blastospores of selected Metarhizium anisopliae 4-2 and Beauveria bassiana 2R-3-3-1, respectively, among two-spotted spider mite-pathogenic fungi. As a result, the virulence was confirmed in all treatments, and the accumulated mortality rates were between 77 and 100% within 7 days. Especially, treatment with the fungal culture filtrate alone exhibited quite high virulence, and combined treatment with aerial conidia or blastospores enhanced activity. However, the median lethal time of treatments was not significantly different. When two isolates were compared, M. anisopliae 4-2 showed higher virulence than B. bassiana 2R-3-3-1. These results suggest that the selected two fungal isolates and their culture products could be used effectively for the control of two-spotted spider mite.

• The Korean Journal of Mycology
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• v.46 no.3
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• pp.333-344
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• 2018

Selection of the optimal culture medium and evaluation of the antimicrobial activity against various phytopathogens were performed for four entomopathogenic fungal isolates with excellent insecticidal and antimicrobial activity against the two-spotted spider mite (Tetranychus urticae), green peach aphid (Myzus persicae), and gray mold (Botrytis cinerea). The optimal medium was selected by measuring the amount of blastospore production and the antifungal activity of the culture medium. On the basis of these experiments, GY medium was selected for Beauveria bassiana 2R-3-3-1 and Metarhizium anisopliae 4-2, SD3, and PDB medium for B. bassiana SD15. The antimicrobial activity test against other phytopathogens indicated that all four isolates showed high antifungal activities against Colletotrichum acutatum and Sclerotinia sclerotiorum. However, for Phytophthora capsici and C. fructicola, only M. anisopliae SD3 showed a high antifungal activity against P. capsici, and the other three isolates had little activity. Antibacterial activity against Clavibacter michiganensis subsp. michiganensis was high in two isolates of M. anisopliae but not in two isolates of B. bassiana. Thus, it was confirmed that entomopathogenic fungi effective for pest control could be effectively used as a control agent for various plant diseases.

• Korean journal of applied entomology
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• v.61 no.1
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• pp.197-210
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• 2022

Entomopathogenic fungi can be used to control a variety of sucking and chewing insects, with little effect on beneficial insects and natural enemies. Approximately 170 entomopathogenic fungal insecticides have been registered and used worldwide, with the recent focus being on the mode of action and mechanism of insect-fungal interactions. During the initial period of research and development, the industrialization of entomopathogenic fungi focused on the selection of strains with high virulence. However, improvement in productivity, including securing resistance to environmental stressors, is a major issue that needs to be solved. Although conidia are the primary application propagules, efforts are being made to overcome the limitations of blastospores to improve the economic feasibility of the production procedure. Fungal transformation is also being conducted to enhance insecticidal activity, and molecular biology is being used to investigate functions of various genes. In the fungi-based pest management market, global companies are setting up cooperative platforms with specialized biological companies in the form of M&As or partnerships with the aim of implementing a tank-mix strategy by combining chemical pesticides and entomopathogenic fungi. In this regard, understanding insect ecology in the field helps in providing more effective fungal applications in pest management, which can be used complementary to chemicals. In the future, when fungal applications are combined with digital farming technology, above-ground applications to control leaf-dwelling pests will be more effective. Therefore, for practical industrialization, it is necessary to secure clear research data on intellectual property rights.