• Current Research on Agriculture and Life Sciences
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• v.1
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• pp.67-83
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• 1983

The new microsporidia S80 isolated from, Bombyx mori L. in Korea showed ovoid in the morphology of the spores and the size were measured $2.9{\pm}0.28{\mu}$ in length and $1.7{\pm}0.29{\mu}$ width. No other microsporidian spore like this has not been so far isolated from Silkworm. The length of the polar filament extruded in hydrogen peroxide ($H_2O_2$) at $30^{\circ}C$ was $26{\mu}$ of a round cytoplasm on the top. The spores were partly stained with Giemsa, Safranin-O and Gram as the same staining properties as Nosema bombycis, Microsporidia K 79 and other microsporidian spores. The fine structures were observed under scanning eleceron microscope through ultrathin sectioning. The spore wall was composed of three layers ; the thin exospore of an electron dense rippled layer, the thick electron lucent endospore which was thinning considerably at the polar filament insertion point, and the inner limiting membrane. Polar cap present at the sporeapex, with a long polar filament of 12-13 coils, subtending angle of $60^{\circ}$ to spore axis, which is tubular made up of a multilayered and are a benes core, light ring structure enclosing the dance core, the dark ring structure enclosing the inner light ring structure and the other than and light ring structure bounded from cytoplasm. Lamellate polaroplast occupied the anterior part of the spore, and the two neclei with dense nucleoplasm bounded by a double nuclear envelope were cited in the slight downer middle portion of spore. From the characteristics of the shape, size and fine structures, it is certain to reason the Microsporidia S80 belong to the phylum Microspora, class Microspora, order Microsporida, order Microsporida. The shape of two nuclei cited seems to be genus Nosema, but in the classification for the suborder it should be defined wheather pansporoblasts be formed or not and for the genis especial attempts have been made to define the characters which distinguish the disporous genera in the life cycle. Survey through the infection of the bad cocoons during 1980 to 1982 in South Korea the areas contaminated with new microsporidia were revealed 5 provinces of Kyung-Gi, Kang-Won, Chung-Nam and Chun-Nam. Pathological effects inoculated per os at second instar larvae of silkworm, the LD 50 was $7.1{\times}10^7/ml$ as lower pathogenecity than that of Nosema bombycis Naegeli of $1.2{\times}10_7/ml$. While on the other hand the inoculation of the microsporidia at fourth instar larvae lowerd the whole cocoon weight and cocoon shell weight and significant at 1% level. The microsporidia S80 defined it can not be transmitted transovarially from the result of predictive and collective examination of 21 egg batches from the infected female moth.

• Journal of Sericultural and Entomological Science
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• v.33 no.1
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• pp.13-20
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• 1991

The flacheric virus(FV) was isolated from the diseased larvae with flaccidity symptoms of the silkworm, Bombyx mori, which were collected in Hyangnam, Kyunggi Province and in Youcheon, Kyungpook Province. The properties of the virus were investigated and compared with the Japanese FV in morphology, size, nucleic acid and structural proteins. The Hyangnam isolate had a diameter of 27$\pm$1, 7nm with speherical shape and contained RNA of which the electrophoretic pattern was same as that of the Japanese FV. The virus had four sturctural proteins and their molecular weight were estimated as 35, 000, 33, 000, 31, 000, and 11, 400 daltons, respectively. The Youcheon isolate had two different sizeds in diameter of 27$\pm$1.7nm and 21$\pm$0.8nm. The antigenicity of the Hyangnam isolate was proved to be identical to that of Japanese FV, whereas the antisera against the Youcheon isolate (mixed with two different sizes) reacted with Japanese FV and densonucleosis virus type 1, respectively. From these characteristic of the isolated viruses, it was concluded that the Hyangnam isolate was identical to the Japanese FV and the Youncheon isolate contained the same viruses as the Japanese FV and DNVI.

• Journal of Mushroom
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• v.15 no.4
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• pp.237-243
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• 2017

In order to develop fermented silkworm "Dongchunghacho" (Paecilomyces tenuipes) with improved absorption and increased effectiveness, we fermented Dongchunghacho using four kinds of microorganisms, viz., lactic acid bacteria, Bacillus subtilis, Natto bacillus, and yeast. A total of 15 samples were fermented using a combination of microbial inoculation culture and conditions to produce fermentation products. The contents of basic components such as sugar, reducing sugar, protein, total polyphenol, and total flavonoid were examined as well as the antioxidant, tyrosinase inhibitory, and thrombolytic activities of the fermented products were analyzed. We observed that reducing sugar and protein contents decreased in most of the fermented products, but the products fermented using yeast exhibited higher sugar content and, thus, higher sweetness. Total polyphenol content and antioxidant activity did not increase in fermented products compared to non-fermented Dongchunghachos, but total flavonoid content and tyrosinase inhibitory and thrombolytic activities increased by fermentation. In particular, total flavonoid content and tyrosinase inhibitory and thrombolytic activities primarily increased in the products fermented using yeast and lactic acid bacteria. However, it was not possible to confirm the increase in these activities in samples fermented by single fermentation using only yeast. Therefore, we propose that it will be possible to develop fermented food from silkworm Dongchunghacho (P. tenuipes) with excellent health benefits through additional study of multiple fermentation conditions using lactic acid bacteria and yeast.

• Journal of the Korean Society of Food Culture
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• v.20 no.4
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• pp.416-420
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• 2005

This study was carried out to make functional laver added with sericulture powder which have a effect of prevention adult diseases such as diabetes mellitus, hypertention, and obesity. In our lab. a lot of study have been performed about functional effect of sericulture(mulberry leaf, silkpeptide and silkworm) for examples decrease of serum cholesterol, triacylglyceride and control of serum glucose in rat. sericulture powder was prepared by pulverizing freeze-dried. Functional laver samples were prepared, and the sensory evaluation quality, physical characteristics and mineral contents of those were compared. In case of overal quality of sensory evaluation, silkpeptide powder laver was lower than other samples. The content of moisture of functional laver added with sericulture powder samples(control, sample 1, 2, 3) were 0.30, 0.98, 0.24 and 0.28%, respectively. The content of crude protein of functional laver added with sericulture powder samples were 40.50, 44.10, 56.75, and 62.50%, respectively. The content of crude fat of functional laver added with sericulture powder samples were 4.00, 4.10, 4.00 and 4.40%, respectively. The content of ash of functional Laver added with sericulture powder samples were 7.07, 7.53, 7.60 and 7.27%, respectively. The content of calcium of functional laver added with sericulture powder samples were 219, 253, 224 and 229mg/100g, respectively. The content of potassium of functional laver added with sericulture powder samples were 1879, 1919, 1890 and 1907mg/l00g, respectively. The content of iron of functional laver added with sericulture powder samples were 18.03, 18.23, 18.46 and 18.53mg/100g, respectively. The content of zinc of functional laver added with sericulture powder samples were 1.86, 4.47, 4.57 and 5.64mg/100g, respectively. The content of manganese of functional laver added with sericulture powder samples were 4.50, 8.50, 7.00 and 6.00 mg/100g, respectively. It was concluded that this functional laver added with sericulture powder is low calorie, high protein and high mineral health food which have a preventive effect of adult disease.

• Journal of Sericultural and Entomological Science
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• v.14 no.2
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• pp.113-123
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• 1972

The authors studied on the effect of silkworm eggs collected from the whole silkworm egg producers in Korea to know the cocoon crops, and the results are as follows. There was no remarkable correlation on the effect of silkworm eggs quality for the cocoon crops but can be concluded as follows. 1) There was a weak correlation between the hatching ratio and economical hatching ratio but no correlation between economical hatching ratio and cocoon crops. In other word, hatching ratio couldn't be influenced for the silkworm health. 5) Non-hybrid ratio (miss-crossing ratio) influenced to the amount of reelable cocoons and pupation ratio but on this experiment, there was a little influence for the cocoon crops. The authors found that there is no difference between origin and its F$_1$crops under the more suitable conditions. Non-hybrid ratio can be determined the silkworm eggs quality, but notice that the ratio decrease only when used pure origin. 3) There is some correlation between harvesting amounts of reelable cocoon and pupation ratio. In general, the eggs which harvest small amounts of reelable cocoon are lower on the pupation ratio. 4) The influence of cocoon layer ratio is based on the variety absolutely but cocoon crops also has a little influence on the cocoon layer ratio.

• Journal of Sericultural and Entomological Science
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• v.49 no.1
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• pp.18-23
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• 2007

The importance of genetic resources conservation and utilization for economy and the health and well-being of societies in general is recognized all over the world. Mulberry genetic resources contain many natural components and are considerable resource for functional sericulture. We carried out antioxidative capacity analysis of mulberry leaves that were collected from Korea and some of foreign countries and preserved in the greenhouse. The mean antioxidant capacity of 34 accessions was 892.30nmol(ascorbic acid equivalent). Also we evaluated fruity characteristics and selected 4 accessions as breeding resources for the production of mulberry fruit. To investigate the effect of tea on antioxidative capacity, five kinds of tea(coffee mix, green tea added brown rice, mulberry leaf tea, Polygonatum odoratum tea and black tea added lemon) were selected and analyzed. Their's antioxidative capacity were 2,531.01nmol, 1,867.42nmol, 1,053.72nmol, 292.71nmol and 188.91nmol, respectively. The antioxidative capacity of drinking water soaked with mulberry leaf showed 891.96nmol.

• Journal of Sericultural and Entomological Science
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• v.21 no.1
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• pp.36-44
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• 1979

Those studies were examined rearing two varieties on Japanese descent and two varieties of Chinese descent by feeding polluted mulberry leaves, non-polluted ones and water-cleaned ones respectively to find effects of air-pollution on the economic characters of silkworms and analysis of contents of Sulphur and Cadmium in the mulberry leaves and silkworms as followings; 1) Japanese descent of polluted part was delayed about 2.5 days than non-polluted part, Chinese descent was delayed about 4 days or inequal and water-cleaned part was medium in the silkworm larval duration. 2) Results of maximum weight of 5th instal, cocoon layer weight and cocoon weight were decreased in due order non-polluted, water-cleaned and polluted in the factors of mulberry 3) Pupal ratio of Japanese descent was not shown statistical significance, but Chinese descent was revealed it obviously in the factors of mulberry leaves. 4) In the resistance of polluted mulberry leaves, Chinese descent was feeble obviously than Japanese and there were some difference even through among the same varieties. 5) The content of S and Cd of polluted area mulberry leaves was increased about 30% respectively than non-polluted area. 6) The fed part of non-polluted mulberry leaves was S 0.41% and Cd 0.013 ppm water-cleaned part was S 0.47% and Cd 0.024 ppm and polluted part was S 0.52% and Cd 0.042 ppm in the contents of S and Cd of silkworm larvae. 7) The contents of S and Cd didn't make visible injury in mulberry leaves but made it seriously in silkworm larvae. 8) The injury of dust on mulberry leaves was more serious than that of quality of mulberry leaves by air-pollution in the economic characters of silkworm. 9) As above results, Chinese descent should avoid contaminated area and it rearing by water-cleaned mulberry leaves can get noticable results in inevitable case on selection of parents silkworm rearingzone.

• Journal of Sericultural and Entomological Science
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• v.28 no.1
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• pp.43-53
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• 1986

Among many microbial pesticides, Bacillus thuringiensis is one of the most hopeful pesticide and some commercial products have been appearing on the market. Because these commercial products contain living spores and toxins of the organism, there is a danger that living spores of B. thuringiensis may be scattered by wind and cause a great damage in the sericulture areas. In order to avoide these risks it is desirable to select the strain which has low pathogenicity to the silkworm, and at the sometime being highly pathogenic to the pest insects. Thus this study has been carried out to acquire some basic informations about the procedure of desicable strain selection. Three strains of B. thuringiensis var. kurstaki, var. dendrolimus and var. aizawai were used for the pathogenicity test on the silkworm, Bombux mori and the fall webwarm, Hyphantria cunea. Those strains were investigated by the agarose gel electrophoresis patterns of plasmid DNA determine whether mutation had occured. Pathogenicity tests were carried out of using isolated crystal proteins and spore-crystal protein to mixtures of each strain, seperatively. In case of using spore-crystal protein mixture, the order of pathogenicity in varities of B. thuringiensis against B.mopri and H.cunea were kurstaki, aizawai, dendrolimus and kurstaki, dendrolimus, aizawai, respectively. But using isolated crystal proteins, dendrolimus had the highest toxicity to H. cunea and the lowest toxicity to B. mori among tested three strains. From the above results, dendrolimus was presumed the most desirable straing for using microbial pesticide.

• Korean journal of applied entomology
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• v.61 no.4
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• pp.675-688
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• 2022

Produced by steaming mature silkworms, HongJam is a natural functional food with various health-promoting effects. The current standard HongJam production protocol involves freezing and freeze-drying steamed mature silkworms for convenient long-term storage and/or selling it to customers. However, freeze-drying HongJam requires a range of processes and costs, which have contributed to its high resale value. In this study, we found that the cost of manufacturing HongJam powder could be reduced by homogenizing steamed mature silkworms using a high-speed blender and digital homogenizer, followed by spray drying. After the homogenized HongJam solution was digested by directly adding food-graded proteases, food-graded protease-digested homogenized HongJam solution was spray-dried. Food-graded digested protease or non-digested homogenized HongJam solutions could be used to produce food for special medical use for patients with general or specific diseases. This more efficient HongJam processing protocol proposed in this study can facilitate the development of sericulture farms and related industries by reducing the production costs of HongJam and its associated products.

• Journal of Sericultural and Entomological Science
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• v.17 no.2
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• pp.141-149
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• 1975

Silkworm is known to be damaged under the unfavorable environmental conditions. Recently, it has been often argued that nicotine is a main factor to affect the silkworm nutritional balance and to result in decrease of quantitative characters, and unbalance of larval nutrition. Especially in spring season, there is tendency to produce nicotine damage to silkworm fed with the mulberry leaf near to tobacco field early cultivated in mulching system. In these connections, the trial was made in the different pots placing by the different distance 10rn, 20m, 40m, and 60m in the direction of east-north from the tobacco field. Location of pot near to the tobacco fold is 40m below the tobacco Held and gradually higher than the tobacco field by 10 degree of slope. In addition, when the mulberry field is divided into two areas from the east-south to west-north, southern east zone is lowering down below 10 degree of slope and has 36％ of east-south wind, 21％ of south-east wind and 16％ of south wind, etc. Pots are left on the mulberry field from the completion of lower part leaf harvest to just before upper part leaf harvest is completed for 32 days. Then silkworm at 4th-5th stage was fed with the leaf grown during the period and larval characters are statistically analyzed. The results are summarized as follows： 1. 10-40m distant pot statistically at the same level has the longest larval duration and 60m distant pot is. not significant at 5％ level. Whole larval duration has same tendency as in the 5th larval duration. 2. Percentage of delayed molting larvae at the 5th stage is increased in 10m distant pot and there is no significance statistically in other pots, as compared with that of control. 3. It is not showed that there is no damage to mortality of the old larvae in 60m distant pot. 4. 10-20m distant pot produces a low pupation and others are at the same level statistically at 5％ significance, 5. It is showed that nicotine damage is occurred in single cocoon freight and cocoon shell weight up to 60m distant pot, rather higher damage in cocoon shell weight than in single cocoon weight. 6. It is showed that cocoon yield from 10, 000 molted larvae including double cocoon is decreased up to 40m distant pot far from the tobacco field in which 40％ of cocoon yield in 10m distant pot by 7kg, 26％ of cocoon yield in 20m distant pot by 3.9kg, 24％ of cocoon yield in 40m distant pot by 3.6kg, and 12％ of cocoon yield in 60m distant pot by 1.8kg, as compared with control. However, there is no significance statistically at 5％ level in 60m distant pot. With these above results, it is concluded that nicotine da mage could be occurred in cocoon yield and cocoon quality up to 60m distant far from the tobacco field.