• Journal of Sericultural and Entomological Science
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• v.15 no.1
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• pp.15-25
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• 1973

The author studied the applicability of Furazolidone to the silkworm rearing industry as a useful remedy for certain silkworm diseases, at the silkworm rearing house of the college of agriculture, Seoul national university, during both the spring and the autumn silkworm rearing season of 1972. Discovering the fact that Furazolidone, when put on the mulberry leaves in a powdered form, is eaten along with the leaves by silkworms and thus the systematic administration of Furazolidone to silkworms is possible, the experimenter carried on a series of experiments (1. determining the in vitro antibacterial activity of Furazolidone to four pathogens of silkworm diseases-Bacillus thuringiensis, Aspergillus oryzae, Aspergillus flavus, and Isaria farinosa, 2. observing the prophylactic and therapeutic effect of Furazolidone against the experimental flacherie caused by inoculation of B. thuringiensis, and 3. examining the toxicity of Furazolidone to silkworm larvae). As the results of the experiments the investigator found out the fundamental fact that Furazolidone exerts a good prophylactic and therapeutic effect against flacherie which is the most common and important silkworm disease: Furazolidone, in in vitro test, inhibited completely the growth of B. thuringiensis, the pathogen of bacterial flacherie, at the concentration of 1 ${\mu}$g/mι. with the tube method and at the concentration of 5 ${\mu}$g/mι. with the plate method, and the drug showed an excellent prophylactic effect and a considerably good therapeutic effect, depending on the time of administration, on the 5th instar silkworms inoculated B. thuringiensis, at the tentative dose of 150mg. per 10 silkworms administered once a day for 2 days. For the practical administration of Furazolidone against flacherie, the dose, the time and duration of administration, and the form of preparation, will be investigated more closely.

• International Journal of Industrial Entomology and Biomaterials
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• v.22 no.1
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• pp.1-4
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• 2011

This study was conducted to test the use of colored cocoon silkworm, Golden Silk, as a host for the fruiting body production of Cordyceps mushroom. Golden Silk variety had a shorter larval period than Yangwonjam at $25.3^{\circ}C$ and 78.5% RH: The average larval period of the Golden Silk was 24 days and 7 hr, and that of the Yangwonjam was 24 days and 15 hr. In the infection test of I. tenuipes on silkworm, the larval period of normal silkworms was longer than the silkworms inoculated with I. tenuipes in both Golden Silk and Yangwonjam. The pupae survival percentage of Golden Silk was 94.4%, whereas it was 91.9% in Yangwonjam. Golden Silk had a higher pupation rate than Yangwonjam. The pupation rate of normal silkworms was about 5% higher than that of silkworms inoculated with I. tenuipes. Infection rate of I. tenuipes into larvae of 5th instar newly exuviated silkworm was 93.8% in Golden Silk, and 96.9% in Yangwonjam. Synnemata production of I. tenuipes was better in Yangwonjam with an incidence rate of 99.8% than Golden Silk with 98.6%. The average synnemata weight of Golden Silk was 1.12 g and that of Yangwonjam 1.29 g. Golden Silk had a lower synnemata weight than Yangwonjam. But no significant difference was observed in synnemata weight varieties. The synnemata of I. tenuipes produced on pupae were white or milky-white in color, and similar in shape and color to wild synnemata collected in Korea.

• Korean Journal of Plant Resources
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• v.34 no.1
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• pp.1-16
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• 2021

The phylogenetic relationships among thirty-two strains (P1~P32; including Cordyceps sp., Paecilomyces sp., Beauveria sp., Aranthomyces sp., Isaria sp. and Himenostilbe sp.) in Miryang region located in the southern part of Korea, were investigated based on internal transcribed spacer (ITS) sequences of ribosomal DNA. A fragment of ITS region was amplified by polymerase chain reaction (PCR) using the specific primer pairs ITS1 and ITS4. After obtained same size of PCR products from various strains, we cloned them into a pGEM-T easy vector to determine their sequences. BLAST analyses of the nucleotide sequence ITS1, 5.8S and ITS2 gene fragments revealed the identity and their phylogenetic relationship. Among 32 strains isolated from Miryang region, Cordyceps militaris was shared 100% sequences with Genbank (AY49191, EU825999, AY491992), while some species are not shared perfectly with reported sequences. For example, strain P17 (P. tenuipes in Ulju-gun Gaji Mountain) has some differences among the other strains of P. tenuipes (Miryang-si Jocheon-eup, Miryang-si Gaji Mountain) and those of gene bank. We conclude that ITS analyses with strains in the suburbs of Miryang in this study can be effectively used as a tool for classification, evaluation and collection of the natural eco-type genetic resources.

• Toxicological Research
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• v.20 no.4
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• pp.339-348
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• 2004

Paecilomyces sinclairii was administered ad libitum feeding at percentage levels of 0, 1.25, 2.5, 5 and 10 percentage (calculated about 8 g/kg)/feeder for a period of 3 months. There was no observed clinical signs or deaths related to treatment in all groups tested. Therefore, the approximate lethal dose of P. sinclairii was considered to be higher than 8 g/kg in rats. Mild decreases in body weight gain were observed dose-dependently in P. sinclairii treated groups in dose response manner after 2 weeks. Interestingly, the weight of abdominal adipose tissues surrounding epididymides were greatly reduced by this Dongchunghacho, in parallel with the mild increase in body weight gain. However, the absolute weight change of other organs was not observed. There were not significantly different from the control group in urinalysis, ocular examination, hematological, serum biochemical value and histopathological examination. From these results, it is concluded that the no-observed-adverse-effect level (NOAEL) of P. sinclairii is less than 1.25% (1 g/kg) in rats in the present study.

• Journal of Sericultural and Entomological Science
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• v.19 no.1
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• pp.19-23
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• 1977

In the previous short communication, the authors reported the applicability of Sodium Hyplochoride solution to silkworm rearing industry as a disinfectant after confirmed the fact that the chemical agent is capable to kill most of the pathogens of silkworm diseases. The authors, in the present study, attempted to investigate the influence of the chemical on the growth of silkworm larvae and the effect on the disinfection of silkworm larvae to inactivate the pathogen of yellow muscardine disease, Isaria farinosa and the results obtained are summarized as fellows. 1. The chemical agent did not affect the growth of silkworm larvae, when it was applied on silk-worm body with the concentration of 1,3,5 per cent of the agent during the rearing period. 2. The Sodium Hypochloride solution did not give any damage to silkworm larvae when larvae were fed up with 1,3,5 per cent of the solution. 3. In the bioassay of the solution on disinfection of larvae inoculated with yellow muscardine disease pathogen, the fact that the agent could control the disease was observed by showing much low infection rate in 3.5 per cent treatment compared to non-treatment control.

• Journal of Life Science
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• v.13 no.4
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• pp.400-411
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• 2003

This study was carried out to identify the phylogenetic relationship and to know the distribution of the entomopathogenic fungi by comparing the DNA sequences of internal transcribed spacer regions (ITS1 and ITS2) and 5.8S ribosomal DNA (rDNA) repeat unit. The entomopathogenic fungi had their specific sequences in ITS1 and 2 regions depending on species. The comparison of the ITS sequences of standard strains indicated that the sequences ITS1 were more variable than those of ITS2. It seems that Paecilomyces tenuipes, Isaria japonicus and P. japonicus are the same species but called as different names because of very similar sequences, and unidentified Paecilomyces sp. KACC 40220 and KACC 40656 showed identical sequences to P. tenuipes. Thirty six strains of the commercial products of entomopathogenic fungi used in this study were divided into four groups by the phylogenetic analysis based on 5.85 rDNA and ITS regions. We found twenty-three strains were P. tenuipes / japonica, eleven strains were C. militaris, and other two strains were Beauveria bassiana and C. multiaxialis, respectively.

• Journal of Mushroom
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• v.12 no.4
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• pp.324-329
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• 2014

For evaluating the anti-allergy activity of mushrooms, forty two mushroom extracts were studied their inhibitory activities on the IgE-mediated degranulation in rat basophilic leukemia cell line (RBL-2H3 cell). Effects of mushroom extracts on the release of interleukin-4 (IL-4) and beta-hexosaminidase, and the cell viability of the IgE-sensitized were measured. From the analysis, five mushroom extracts such as the water extract from Flammulina velutipes (Curt.:Fr.) Sing showed the suppressive activities on IL-4 release as 20%. Eight extracts including the water extract of Ganoserma lucidum showed the suppressive activities on ${\beta}$-hexosaminidase release as 20%. Almost all of the extracts stimulated the proliferation of RBL-2H3 cell. The water extracts of Flammulina velutipes and Phellinus linteus were examined against the inhibitory activity in the production of IL-4 and ${\beta}$-hexosaminidase. Additionally, the extracts from Ganoserma lucidum, Isaria japonica, Phellinus linteus and Pleurotus ostreatus inhibited dose-dependently on ${\beta}$-hexosaminidase production. In conclusion, the result suggests that the mushrooms with the potent inhibitory efficacies on the degranulation of the mast cell would be candidate resources for the anti-allergy resources, and thus need to study for their utilization.

• 한국균학회소식:학술대회논문집
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• 2016.05a
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• pp.13-13
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• 2016

Insects constitute the largest and most diverse group of animals in the world. They also serve as the hosts or nutrient sources for an immense assemblage of pathogens, parasites, and predators. More than 700 fungal species from 100 genera have adopted an entomopathogenic lifestyle. Although entomopathogenic fungi were studied as only biocontrol agents against a variety of pests in various countries, it has been recently focused their additional roles in nature. They are antagonists to/against plant pathogens, endophytes, and possibly even plant growth promoting agents. The potential antimicrobial effect against fungal plant pathogens by an isolate of entomopathogenic fungi including Beauveria bassiana, Lecanicillium spp., and Isaria fumosorosea have been reported since late 1990s, but wasn't reported pathogenicity of the isolate against pests. Later, a Canadian Lecanicillium sp. isolate and L. longisporium isolated from Vertalec$^{(R)}$ showed simultaneous control effect against both aphid and cucumber powder mildew. Therefore, the antimicrobial activities of 342 fungi isolates collected from various regions and conditions in Korea were evaluated against plant pathogenic fungus Botrytis cinerea using dual culture technique on agar plate. As a result, 186 isolates (54.4%) shown the antifungal activity against B. cinerea. The culture filtrates of selected fungi completely suppressed the growth of the microorganisms, indicating that suppression was due to the presence of antimicrobial substances in the culture filtrate. Mode of action of these fungi against insect involves the attachment of conidia to the insect cuticle, followed by germination, cuticle penetration, and internal dissemination throughout the insect. During infection process, secreted enzymes, proteinous toxins, and/or secondary metabolites secreted by entomopathogenic fungi can be used to overcome the host immune system, modify host behavior, and defend host resources. Recently, secondary metabolites isolated from entomopathogenic fungi have been reported as potential bioactive substances. Generally, most of bioactive substances produced by entomopathogenic fungi have reported low molecular weight (lower than 1,000 g/mol) as peptide and, in contrast the high molecular weight fungal bioactive substances are rare. Most substances based on entomopathogenic fungi were shown antimicrobial activity with narrow control ranges. In our study we analyzed the antimicrobial substances having antagonistic effects to B. cinerea. Antimicrobial substances in our fungal culture filtrates showed high thermostability, high stability to proteolytic enzymes, and hydrophilicity and their molecular weights were differed from substance. In conclusion, entomopathogenic fungi showed pathogenicity against insect pests and culture filtrate of the fungi also shown to antimicrobial activity. In the future, we can use the entomopathogenic fungi and its secondary metabolites to control both insect pest control and plant pathogenic fungi simultaneously.

• Journal of Sericultural and Entomological Science
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• v.50 no.2
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• pp.101-108
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• 2012

This study was conducted to confirm the mass production of male pupae and sex-limited larval marking variety as a host for synnemata production of Isaria tenupes in RDA(Rural Development Administration). Silkworm pupation, infection rate and synnemate formation of I.tenuipes were examined. Among the silkworm varieties tested, male Hansaengjam showed the highest pupation rate at 98.7%. I. tenuipes infection rate of larvae of newly-exuviated 5th instar silkworm was 83.7 ~ 90.4% in the spring rearing season and 91.7 ~ 96.6% in the autumn rearing season. Synnemata production of I. tenuipes was execellent in female Yangwonjam with an incidence rate of 99.5% followed by male Yangwonjam(99.5%) and Baegokjam(99.4%) in the spring and autumn rearing season. Synnemata living weight ranged from 0.93 ~ 1.25 g in the spring rearing season. The female Hansaengjam had the heaviest synnemata weight(1.25 g). Synnemata dry weight ranged from 0.27 ~ 0.35 g in the spring rearing season. The female Yangwonjam had the heaviest synnemata weight(0.35 g).