• 한국축산식품학회지
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• 제38권1호
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• pp.172-179
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• 2018

One of the critical limitations to use of bacteriocins produced by lactic acid bacteria as a substitute for chemical antibiotics is the narrow spectrum of their antibacterial activity. The aim of present study was isolation and molecular identification of bacteriocin-producing enterococci with broad antibacterial spectrum. Bacteriocin-producing bacteria were isolated from native dairies in Kerman. Bacteriocins were purified by ammonium sulfate method and the effects of them were investigated on different strains of bacteria. Also, the effects of pH and heat on produced bacteriocins were investigated. High level bacteriocin-producing isolates were identified based on molecular tests. A total of 15 strains of bacteriocin-producing Enterococcus were isolated initially. Enterococcus faecium C-2 and Y-1 strains produced bacteriocins with the highest antibacterial effect. The bacteriocins were stable in pH ranges from 2 to 12 and their antibacterial activity was maintained after autoclave treatment. The maximum bactericidal effect was observed against Listeria monocytogenes and Pseudomonas aeruginosa. In conclusion, use of these bacteriocins as a substitute for chemical antibiotics is recommended.

• 한국가축번식학회지
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• 제19권2호
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• pp.89-93
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• 1995

In this study was demonstrate that retrovirus-mediated gene transfer is one of the promising alternatives to the conventional pronuclear DNA microinjection approach, especially in transferring the exogenous genes into the boving embryos. By co-culturing of zona of zona-free one-cell stage embryos with the retrovirus-producing cells for 24 hours followed by 6 days of culture in virus-free medium, we could get morulae and blastocysts expressing the E. coli LacZ genes which were transferred by our retrovirus vector. The results obtained in this study are summarized as follows : 1. Addition of 5$\mu\textrm{g}$/ml of polybrene in the embryo and virus-producing cell co-culture medium did not affect development of zona-free one-cell embryo. 2. Compared with the intact embryos removal of zona at one-cell stage before co-culturing with the virus-producing cells for one day caused only slight decrease of embryo develpment. 3. Co-culture of 625 zona-free one-cell stage embryos with the virus-producing cells resulted in 65(10.4%) morulae or blastocysts, and 12.3%(8/65) of the morulae or blastocysts were E. coli LacZ positive.

• 한국항공운항학회지
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• 제13권1호
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• pp.43-49
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• 2005

There are several ways to mold the complex material, and it is divided to vacuum pack mold, compression mold, and hand lay up for a high molecular substance as a basic material. Moreover, it can be divided to general manufacturing (Single form) and mold manufacturing(Mold form) under normal temperature for Firefly. Firefly was manufactured with hand lay up and general manufacturing that using the foam core, glass fabric, and template without mold. However, mold manufacturing that is producing the surface by semi-sandwich using thin foam core and glass fabric then reinforce the inside with spar and rib is on developing. Mold manufacturing can make easy to production, standardize the quality, and possible to mass producing. In this paper, we present the mold producing process for canard aircraft "Firefly", and the problems and solutions during producing Firefly. Moreover, it complements the defect that the problems caused by master manufacturing error when produce several masters of a large part, and make the manufacturing process to be shortened by the replacement from the supplementary plate to the foam that is installed when producing lay up mold.

• 한국잠사곤충학회지
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• 제13권2호
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• pp.99-107
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• 1971

전자현미경관찰에 의하여 가잠의 식도하신경구에서 휴면요인세포(diapause factor cell)에 어떤 정보를 주는 것으로 생각되는 휴면조절세포(diapause regulator producing cell)를 발견하였다. 휴면조절세포의 과립은 이 세포가 부분적으로 둘러싸고 있는 휴면요인세포의 과립의 직경보다 크며(직경 .2,000∼5,000A), 휴면란을 산란하는 개체의 휴면조절세포에서는 전자밀도가 높은 리소좀이 관찰되었으나, 비휴면란을 산란하는 개체에서는 이것이 관찰되지 않았다. 다수의 세포질과립이 리소좀과 결합되었다가 소형의 과립으로 되어 리소좀으로부터 나오는 것이 발견되었다. 휴면요인세포와 휴면조절세포에 대하여 논하였다.

• 전기학회논문지
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• 제59권12호
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• pp.2250-2255
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• 2010

An fine silver particle has a variety of uses, such as in killing micrograms and as catalysts. Many techniques have been used for the production of the fine particles. Faraday cell, consisting of two silver electrodes in an electrolyte, is unique, but it is hard to get a very fine particle by this method. A finer silver nano-particle producing cell, utilizing a dielectric bed as a lower electric current and higher field controlling means, has been proposed and investigated. The I-V characteristics of the cell and effect of the dielectric bed on the producing finer silver nano-particles have been investigated. The I-V characteristics of the cell with the dielectric bed were different from that of the same system without the bed, due to the increased cell resistance and elevated electric field intensity. It is found that the proposed cell with the dielectric bed can produce finer silver nano-particles effectively, which, however, can be used as one of effective fine silver nano-particle producing means.

• 한국미생물·생명공학회지
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• 제3권1호
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• pp.1-6
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• 1975

각거 시요로부터 분이된 215주의 Rhizopus 속중 lipase생성자이 강한 1 주를 선정하여 균학적 성질 및 lipase생성 조건을 검토한 결과는 다음과 같다. (1) 우수균주 strain K52는 균학적 제성질을 살펴본 결과 Rhizopus delemar에 유사하였다. (2) 배양기간은 밀기울 고예배양의 경우 48시간, 액면배양의 경우는 96시간, 진악배양의 경우는 72시간 경과후 최고의 역가를 나타 내었다. (3) 진종배양시보다 액면배양시에 lipase의 생성이 더욱 양호하였다. (4) 밀기울 고예배양시에도 효소의 생성이 양호하였으며 배양 48시간후 3.800(u/g)의 활성을 나타내었다. (5) 배양최적온도는 액체배양시나 국체배양시 모두 3$0^{\circ}C$가 가장 양호하였다.

• 한국미생물·생명공학회지
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• 제28권6호
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• pp.309-315
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• 2000

To isolate yeast strains producing high concentration of ethanol, 125 strains were subjected to screening. Initially 14 strains able to grow in a medium containing 15%(v/v) ethanol, 7 strains capable of growing in a medium containing 50%(v/v) glucose, 23 strains having relatively fast fermentation rates, 13 strains able to grow at $42^{\circ}C$ were selected. After secondary screening, 11 strains having relatively high ini-tial fermentation rate and producing high concentration of ethanol were selected. After tertiary screening 5 strains producing high concentration of ethanol were selected. These 5 strains were again for their ethanol produc-tion, residual sugar, and viability using fermentation medium containing 25% glucose. The strain producing the highest concentration of ethanol was 20-1 strain which produced 10.56%(v/v) ethanol in 4 days, and the highest viable strain was 11-1 which produced 10.35%(v/v) ethanol(13.1%. v/v) with the viability of 30.44% after 5 days of fermentation. Both of the 20-1 and 11-1 strains were identified as Saccharomyces cerevisiae.

• Food Science and Biotechnology
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• 제15권6호
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• pp.896-901
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• 2006

Patulin is a food mycotoxin which induces genotoxicity and acute intestinal disease in infants. Patulin mainly originates from fruit putrefactive moulds, especially in apples, which necessitates the maintenance of strong safety standards against patulin for fresh and processed apples. To investigate the patulin producing moulds in Korean apples, 16 morphological types of fungi were isolated from Korean apples and a patulin producing fungus was identified based on a sequence analysis of the region of internal transcribed spacers (ITS5-5.8S-ITS4 region, 505 base pair) and the 26 rRNA D1/D2 region (527 base pair). Morphological analyses were also performed. The isolated patulin producing fungus was found to a representative species of Penicillium crustosum. The maximal patulin production ability of the isolated fungus (P. crustosum) and the patulin producing standard strain (P. griseofulvum, ATCC 46037) in an SY broth medium were 0.32 and 2.46 mg/L, respectively.

• 한국수산과학회지
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• 제49권5호
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• pp.573-581
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• 2016

Bacterial decarboxylation of amino acids in food leads to the production of biogenic amines, which can cause reactions in human that include headaches, nausea, palpitations, chills, and severe respiratory distress. The amine putrescine is an especially effective inhibitor of metabolizing enzymes and amplifies histamine intoxication and tyramine poisoning. Using an L-ornithine decarboxylating medium, we isolated 14 putrescine-producing bacteria from sand lance, Ammodytes personatus, sauces. The isolates were identified, using an API kit and 16S rRNA analysis, as Lysinibacillus fusiformis (1 strain), Lysinibacillus xylanilyticus (6 strains), Lysinibacillus macroides (1 strain), Lysinibacillus sphaericus (3 strains), Bacillus fusiformis (1 strain), Paenibacillus favisporus (1 strain), and Staphylococcus caprae (1 strain). These strains produced between 1.66 to 236.97 μg/mL of putrescine after 48 h incubation. Lysinibacillus spp. were the dominant putrescine-producing bacteria in sand lance sauces, which produced 236.97 μg/mL of putrescine from a culture broth containing 0.5% L-ornithine. This is the first report on the isolation and identification of putrescine-producing bacteria from sand lance sauces.

• 동아시아식생활학회지
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• 제16권1호
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• pp.93-98
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• 2006

This study examined whether or not the iron that is accumulated in the recombinant microbes that produce ferritin is bioavailable to rats with iron deficiency. Rats induced with iron deficiency were treated with iron preparations of $Fe(NH_4)_2(SO_4)_2$, horse spleen ferritin, control yeast, and ferritin-producing recombinant yeast for 14 days. The bioavailability of iron was examined by measuring hemoglobin concentration, hematocrit value, and tissue iron stores. Differences between dietary groups were determined by one-way ANOVA, at the level of significance p<0.05. Based on hemoglobin concentration and hematocrit value, iron in $Fe(NH_4)_2(SO_4)_2$, horse spleen ferritin, and ferritin-producing yeast were bioavailable in rats and cured iron deficiency. The efficacy of ferritin and ferritin-producing yeast was confirmed in establishing tissue iron stores after the induction of iron deficiency. The iron sources of ferritin and the ferritin-producing yeast seemed to be as effective for the recovery from iron deficiency as the iron compounds of ferric citrate and ferrous ammonium sulfate. The results suggest that the iron stored in ferritin of the recombinant yeast is bioavailable, and that the recombinant yeast may contribute widely as a source of iron to resolve the global problem of iron deficiency.