• Journal of Ginseng Research
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• v.23 no.3 s.55
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• pp.130-134
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• 1999

Somatic embryos were induced directly from cotyledon explants of Korean ginseng (Panax ginseng C.A. Meyer) on Murashige and Skoog (MS) medium with 2,4-D, BAP, kinetin or lacking growth regulators. When somatic embryos formed on all media grew to cotyledonary stage, the further development of embryos was ceased and remained in white color. By gibberellic acid (over 1.0 mg/1 $GA_3$) treatment, all the somatic embryos turned rapidly to green and germinated within 3 weeks. Chilling treatment also induced the germination of somatic embryos. The effective temperature regime was $-2^{\circ}C$ for over 8 weeks but more higher temperature than $0^{\circ}C$ did not effective for germination of somatic embryos. Ultrastructural observation revealed that the cotyledon cells of somatic embryos without chilling or $GA_3$ treatment contained numerous lipid reserves, dense cytoplasm, proplastids and non-activated mitochondria with poorly differentiated internal structure, but the cotyledon cells of germinating somatic embryos after chilling or $GA_3$ treatment highly vacuolated and contained well-developed chloroplasts and active state of mitochondria enclosing numerous cristae. The above results indicate that in vitro developed somatic embryos of Panax ginseng may be dormant after mature similar to zygotic embryos.

• Journal of Ginseng Research
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• v.23 no.4
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• pp.205-210
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• 1999

The growth of hairy roots were increased $69\%$ by 0.1 mM DCPIP under light conditions. In these conditions, the contents of seven ginsenosides were none significant variation. The influence of electron inhibitors on growth and ginsenoside contents in ginseng hairy roots was tested. The growth was inhibited $71\%\;and\;22\%$ respectively by CCCP and methylamine. The ginsenoside contents were as decreased above $45\%$ in all treatment tested except triazine treatment. In antioxidants treatment, the growth of hairy roots was increased about $68\%$ by propylgallic acid, about $23\~25\%$ by ascorbic acid or 2,5-dimethylfuran, while the contents of seven ginsenosides were none significant variation. The ginsenoside productivity was high when hairy roots were cultured in $\circledR^{\wedge}MS$ medium for 4 weeks and then transferred to 1/2MS medium with ascorbic acid or 2,5-dimethylfuran for 1 weeks in light conditions. It is suggested that ginsenoside productivity could be accelerated by some antioxidants in hairy root cultures of ginseng.

• Korean journal of applied entomology
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• v.16 no.3 s.32
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• pp.149-154
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• 1977

Effect of Simazine(2-chloro-4,6-bis (ethylamino)-s-triazine), Nitrofen (2, 4-dichloro-4' -nitrodi­phenylether), Propanil (:3, 4-dichloropropionanilide), and Butachlor (2-chloro-2, 6-diethyl N-(buthoxy­menthyl) acetanilide on urea hydrolysis and subsequent nitrification was investigated in an upland soil incubated at $20\pm1^{\circ}C$. 1. All the herbicides tested had no effect on the hydrolysis of urea to ammonia at the recommended rates. Butachlor, at ten and fifty times the recommended rate, and Nitrofen, at fifty times the recommeded rate, depressed urea hydrolysis, resulting in reduction of ammonia. But the depressive effects were temporary, disappearing soon. Simazine and Propanil had no detrimental effect on urea decomposition at all the treated rates. 2. Also, all the chemicals tested had no effect on the nitrification process at the recommended rates. At higher concentrations of ten and fifty times the recommended rate Butachlor and Nitrofen inhibited the oxidation of nitrite, and propanil long inhibited the oxidation of ammonium to nitrite, but was inactive against nitrite oxidizer. These inhibitive effects of the chemicals, however, disappeared in the later period of incubation. Simazine had no effect on the nitrification process at all the treated rates. 3. The trend of change in soil pH of both the treated and untreated plots well reflected the change of soil nitrogen forms during incubation. No direct effect of the chemicals on soil pH was obserbed.

• Korean Journal of Microbiology
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• v.24 no.2
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• pp.154-160
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• 1986

In order to develope interspecific fusion of the genus Cellulomonas capable of assimilation cellulose, the optimun conditions for the protoplast formation was investigated to examine the susceptibility of cell wall, between different species of the same genus using scanning electron microscope. The variation in the susceptibilities of Cellulomonas sp. CS 1-1 and C. flavigena to lysozyme treatment were considerably remarkable, although they belong to the same genus. The rate of protoplast formation of CS1-1 was 99.9% being treated with lysozyme $(100{\mu}g/ml)$ for 30 minute and that of C. flavigena was about 80% being treated at the concentration of $600{\mu}g/ml$ of lysozyme for 6 hours. The susceptibility of cell wall to the lysozyme treatment on protoplast formation of the strain, CS1-1 seems not to be depend on the cultural periods of cells. On the contrary, that of C. flavigena was considerably depend on the periods. Cells of C. flavigena at mid exponential phase could be more efficiently converted to protoplast cells than those at late exponential phase be done. The rate of the protoplast formation was 95%, when cells of C. flavigena at mid exponential phase were treated with lysozyme $600{\mu}g/ml$ for 6 hours and observed by SEM. In the evalution of protoplast formation of the CS1-1 results of counting method in plate after osmotic shock treatment were similar to the results of the direct observation method by means of SEM. But in the case of C. flavigena the latter method was much more reliable than the former, because the differences between the number of spheroplasts and protoplasts were not able to figure out on conuting the number of protoplast after osmotic shock tretment.

• Journal of Korean Society of Forest Science
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• v.96 no.4
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• pp.425-431
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• 2007

To investigate genetic diversity and PCR detection of Rhizina undulata, PCR detection and sequence analysis of rDNA ITS region of R. undulata in soil were analyzed and developed. The length of partial 18S rDNA from four R. undulata isolates were 1,375 nt. The sequence similarity of R. undulata isolates was 100%. The rDNA ITS regions of R. undulata isolates were 585 nt long. Nucleotide sequencing of the ITS regions showed that PDK-1, PTT-1 and PDJ-9 isolates had 100% sequence identity. But, PDS-5 isolate differed from the three isolates by two nucleotide substitution. R. undulata-specific primers designed by the sequence of ITS region were used in PCR detection of R. undulata. PCR products about 525 bp size, which is specific to R. undulata, were amplified from total DNAs of R. undulata isolates. To assay the sensitivity of PCR detection by R. undulata ITS-specific primer, purely cultured mycelial suspension of R. undulata was serially diluted and mixed with 100g of sterile sandy loam soil, respectively. And then, PCR products of total DNAs extracted from each mycelium-soil mixtures were analysed. The PCR protocol could detected up to 1ng mycelium of R. undulata within 100g of soil.

• Korean Journal of Health Education and Promotion
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• v.15 no.1
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• pp.133-149
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• 1998

본 연구는 미국에 사는 한국인 이민자들의 암예방과 식품에 대한 지식과 신념에 관하여 알아보는데 그 목적이 있다. 본 연구의 도구로는 미국 국민 건강연구조사 (NHIS)의 설문지를 한국어로 번역하였고, 연구의 대상자는 미국의 시카고에 거주하는 263명의 한국인 이민자들이다. 본 연구의 주된 연구결과는 다음과 같았다. (1) 대부분의 대상자(83.3%)들은 한국음식을 먹고 있다고 답하였다. (2) 대상자들의 47.5%가 영어를 전혀 못 읽거나 거의 못 읽는다고 답하였다. (3) 식생활 변화를 하지 않는 이유에 대해 현재 먹고 있는 음식을 즐기기 때문에 식생활을 바꾸고 싶지 않다는 답이 가장 많았다. (4) 우리가 먹고 마시는 음식과 관계 있는 주요질병에 대해서 25.4%의 응답자만이 암이라고 답하였다 (미국 NHIS 에서는 48%). (5) 응답자의 48.3%만이 섬유소에 대해 들어보았다고 응답하였다. (6) 7.1%의 응답자만이 섬유소가 많은 음식으로 corn flakes와 bran flakes를 고를 수 있었다. 이 결과로 보아 한국인 이민자들이 미국음식에 대해 잘 모르는 것으로 보인다. (7) 약 62%의 응답자들이 암예방에 관한 무료 보건강좌에 참석하고 싶다고 응답하였다. 보건강좌 장소에 대해 "교회'라고 답한 응답자가 가장 많았다. (8) 질병예방에 관한 정보를 어디에서 얻느냐는 질문에 대하여 "신문"이라고 답한 응답자가 가장 많았다. 본 연구에서 얻은 결과를 볼 때 대부분의 응답자들이 미국 정부에서 하고 있는 암예방 교육의 혜택을 받고 있지 않는 것으로 나타났다. 한국인 이민자들의 문화적 배경에 맞는 암교육이 필요하며, 영어를 잘 못하는 이민자들을 위해 한국말로 번역된 보건교육자료를 사용하여야 한다.교육자료를 사용하여야 한다.표현을 위하여 확장된 기본 모델을 중심으로 각 레벨의 구성 요소들의 형식적 의미(formal semantics)와 레벨 내 혹은 레벨 구성요소들간의 관계성(relationship), 그리고 제약조건의 표현과 질의 추론 규칙들을 식별하여 FOPL(First Order Predicate Logic)로 표현한다. 또한, 본 논문은 FOPL로 표현된 predicate들과 규칙들을 구현하기 위하여 Prolog로 변환하기 위한 이론적 방법론을 제시하고 정보자원 관리를 위한 기본 함수들과 스키마 진화(schema evolution)를 위한 방법론을 제안한다. 최저 잔류탁도를 나타내는 최적 응집제 주입량에서의 Zeta potential은 원수탁도가 5NTU일 경우 Alum, PAC 및 PACS 모두 -20mV∼-15mV사이였으며, 원수 탁도가 10NTU인 경우에는 0∼0.5mV 범위에 있는 것으로 나타나 응집제 종류 및 주입량이 상이하더라도 응집효율이 가장 양호한 상태에서의 Zeta potential은 일정한 범위내에 있는 것으로 나타났다.각 각 11.1, 10.2, 12.2 그리고 13.0%의 발달율을 보여 유의적인 차이를 보이지 않았다. 4. 수정 후 114 시간 개별배양된 수정란으로부터 분리된 small과 large의 할구를 공핵체로 사용한 처리구에서 핵이식 수정란의 세포융합율에 있어서 각각 71.0, 71.4, 69.9 및 77.1% 의 융합율올 보여 유의적인 차이를 나타내지 않았으며, 핵이식 수정란의 배반포기배로의 발달율에 있어서도 각각 11.4%, 8.0%, 17.2% 그리고 12.9% 의 발달율을 보여 유의적인 차이를 보이지 않았다. 이상의 결과로 보아 핵이식 수정란을 효율적으로 생산하기 위하여 수핵난자의 세포질에 ionomycin 과 DMAP 의

• Korean Chemical Engineering Research
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• v.51 no.4
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• pp.482-486
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• 2013

Recently, biohydrocarbons are gathering an interest as a new bioenergy due to the versatile applicability. In the present work, a process is proposed for the recovery of lipids from Recombinant E. coli MG1655 which provides longer chain fatty acids. After the growth of the recombinant E. coli, the cells were disrupted by high pressure homogenizer for obtaining intracellular lipids and the resulting solutions were centrifuged and extracted. For the efficient cell disruption with high pressure homogenizer, the pressure higher than 5,000 psi was required. In addition, under the conditions of applied pressure 5,000 to 20,000 psi, 1~3 pass homogenizing was enough for the more than 90% cell disruption. As organic solvents for extraction of lipid, hexane/isopropyl alcohol and ethyl acetate/ethanol systems showed excellent extracting power. With these solvent systems, the 60% lipid could be recovered. Moreover it was found that the extracted lipids contained long-chain fatty acids such as $C_{12}$, $C_{14}$, $C_{16}$ and $C_{18}$.

• Korean Journal of Agricultural Science
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• v.14 no.1
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• pp.16-25
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• 1987

Colletotrichum acutatum, C. coccodes, C. dematium and C. gloeosporioides were detected in seed samples of red pepper (Capsicum annuum). C. dematium and C. gloeosporioides were the predominant species, maximum seed infection of the species in some samples were 84% and 28%, respectively. C. acutatum and C. coccodes were recorded only in low percentages of 1-2. The blotter method proved more suitable for detecting Colletotricum spp. than the deep freezing blotter or agar plate methods. Plating of seed components showed that C. dematium and C. gloeosporioides were recovered more frequently from seed coat, and decreasing amounts of infection were observed in the endosperm and cotyledon. Seed-borne C. dematium and C. gloeosporioides caused seed rot, damping-off, seedling blight and brown discoloration of cotyledon and hypocotyl when infected seeds were sown in agar of test tube or in soil. Inoculation experiments showed that C. acutatum was pathogenic to red fruit of red pepper and C. coccodes was highly pathogenic to red fruit and weakly pathogenic to leaf of the plant. C. dematium was highly pathogenic to leaf and green fruit and C. gloeosporioides was pathogenic to not only leaf but also green and red fruits. Host range of the four seed-borne species of Colletotrichum was also investigated.

• Food Science and Preservation
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• v.9 no.4
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• pp.429-433
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• 2002

The D-xylulokinase from Candida sp. L-16 was purified through a sequence of ammonium sulfate fractionation, DEAE-cellulose chromatography, Sephadex G-100 and Sephadex G-200 gel filtration. The specific activity of the purified Dxylulokinase was increased to 23.2 fold and the yield was 11.2%. The enzyme was showed to be a single protein band by SDS-PAGE. The molecular weight of the enzyme was 150,000 dalton, this enzyme was identified to be a dimer with two subunits. The optimum conditions of the enzyme were pH 8.0 and 40$\^{C}$, respectively. The enzyme was relatively stable between pH 7.0 to pH 9.0, but it was unstable over 30$\^{C}$. The enzyme showed substrate specificity on D-xylulose, D-arabinose and D-ribose, Km value and Vmax for D-xylulose were 0.042 mM and 117 units/ml, respectively. The activation energy of the enzyme was 4.75 Kcal/mol. The one was inhibited by metabolic intermediates such as 6-phosphogluconic acid, 2-keto-gluconic acid. The enzyme was activated by EDTA and thiol compounds such as cysteine-HCI, DTT and glutathione.

• Korean journal of applied entomology
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• v.23 no.2 s.59
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• pp.89-95
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• 1984

Sixty isolates of Dendrophoma obscurans isolated from 19 important strawberry growing areas of Korea were tested in vitro for resistance to thiophanate-methyl and iprodione. Naturally-occurring thiophanate-methyl-resistant isolates were about 43 percents of isolates tested, whereas iprodione-resistant isolates were 10 percents. All these resistant isolates except SU 1 and SU 2, which were highly resistant to thiophanate-methyl, showed a week level of resistance. Iprodione-resistant isolates were readily obtained in vitro, when mycelial disk of the fungus was incubated on PDA media containing iprodione at the concentrations of $1{\mu}g/ml\;and\;10{\mu}g/ml$, but no thiophanate-methyl-resistant isolate from the mycelia with or without UV irradiation. All these artificially-obtained iprodione-resistant isolates were showed a high degree of resistance. On the strawberry leaves, thiophanate-methyl and iprodione were no longer effective to all resistant isolates at the recommended concentration, and the protective value to highly resistant isolates was much less than that of weakly resistant isolates. Isolates resistant to thiophanate-methyl were also resistant to benomyl but iprodione-resistant isolates did not show cross-resistance to thiophanate-methyl, benomyl, captan and zineb. Captan controlled both thiophanate methyl-resistant and iprodione-resistant isolates as effectively as sensitive isolates.