• Food Science of Animal Resources
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• v.38 no.1
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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.

• Korean Journal of Animal Reproduction
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• v.19 no.2
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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.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.13 no.1
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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.

• Journal of Sericultural and Entomological Science
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• v.13 no.2
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• pp.99-107
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• 1971

In the suboesophageal ganglion of Bombyx mori, the diapause regulator producing cells which may give an information to the diapause factor cells were found by means of electron microscopy. The diapause regulator producing cells had larger granules (2000 to 5000 A$^{\circ}$ in diameter) than did the diapause factor cells which were partially surrounded by the formers. Highly electron-dense material of lysosome in the diapause regulator producing cells was observed in the diapause-egg producer but such lysosomes were not in the non-diapause egg-producer. It was found that many cytoplasmic granules fuse with lysosome, and smaller granules come out of lysosomes. Some implications of the diapause factor cell and the diapause regulator producing cell were discussed.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.12
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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.

• Microbiology and Biotechnology Letters
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• v.3 no.1
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• pp.1-6
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• 1975

The excellent strain $K_{52}$ for producing lipase was selected among 215 strains of Rhizopus sp. isolated from soil and other natural sources. The results investigated of microbiological characters and conditions for producing lipase Ivere summarized as follows： (1) Strain $K_{52}$ was similar to Rhizopus delemar in microbiological character. (2) The lipase activity was most vigorous after 48 hours in wheat bran culture, 96 hours in surface culture and 72 hours in shaking colure. (3) Surface culture was more suitable than in shaking culture for producing lipase. (4) In the case of wheat bran culture, producing of lipase was vigorous after 48 hours of culure period (3,800u/g) . (5) The optimum temperature for producing lipase was 3$0^{\circ}C$ both in wheat bran culture and in surfase culture.

• Microbiology and Biotechnology Letters
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• v.28 no.6
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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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• v.15 no.6
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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.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.5
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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.

• Journal of the East Asian Society of Dietary Life
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• v.16 no.1
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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.