• Title/Summary/Keyword: Agar 농도

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Preparation Conditions of Agar Oligosaccharides with Organic Acids (한천 올리고당 제조를 위한 유기산 처리 조건)

  • JOO Dong-Sik;KIM Ok-Seon;CHO Soon-Yeoung;LEE Chang-Ho
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.36 no.1
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    • pp.6-10
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    • 2003
  • The optimum organic acid and temperature conditions were investigated for the preparation of oligosaccharides from agar. The tested organic acids were acetate, citrate, lactate, malate, and succinate and the conditions for oligosaccharides preparation were $0.3\%,\;0.5%;and\;0.7\%$ organic acid concentrations at $80\~120^{\circ}C.$ The low concentration of organic acid below $0.3\%$ decreased the degrading ratio and the high concentration up $0.5\%$ could not changed the degrading ratio. Conditions below $100^{\circ}C$ was not good for degrading agar. But $100^{\circ}C\;or\;120^{\circ}C$ was optimal temperature conditions for agarooligosaccharides according to the organic acid type and concentration. The organic acid concentration was $0.5\%$ and organic acid was the citrate or malate. The treatment time considered optimum was 120$\~$180 min. The maximal degrading ratio giving optimum conditions such as $100^{\circ}C\;and\;120^{\circ}C\;was\;35.5\%\;and\;38.7\%,$ respectively. The agarooligosaccharides prepared by autoclaving at $100^{\circ}C\;and\;120^{\circ}C$ were 2$\~$7 species oligomer.

Characteristics of OCP of Reinforced Concrete Using Socket-type Electrodes during Periodic Salt Damage Test (주기적 염해 시험에 따른 소켓 타입 전극을 활용한 철근 콘크리트의 OCP 특성)

  • Lee, Sang-Seok;Kwon, Seung-Jun
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.25 no.4
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    • pp.28-36
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    • 2021
  • It is known that buried rebars inside concrete structures are protected from corrosion due to passive layer. It is very important to delay the timing of corrosion or evaluate a detection of corrosion initiation for the purpose of cost-beneficiary service life of a structure. In this study, corrosion monitoring was performed on concrete specimens considering 3 levels of cover depth(60 mm, 45 mm, and 30 mm), W/C(water to cement) ratio(40.0%, 50.0%, and 60.0%) and chloride concentration(0.0%, 3.5%, and 7.0%). OCP(Open Circuit Potential) was measured using agar-based socket type sensors. The OCP measurement showed the consistent behavior where the potential was reduced in wet conditions and it was partially recovered in dry conditions. In the case of 30 mm of cover depth for most W/C ratio cases, the lowest OCP value was measured and rapid OCP recovery was evaluated in increasing cover depth from 30 mm to 45 mm, since cover depth was an effective protection against chloride ion ingress. As the chloride concentration increased, the effect on the cover depth tended to be more dominant than the that of W/C ratio. After additional monitoring and physical evaluation of chloride concentration after specimen dismantling, the proposed system can be improved with increasing reliability of the corrosion monitoring.

Effects of Heavy Metal Concentrations on Seed Germination and Rhizome Development of Campanula takesimana Nakai (중금속 농도가 섬초롱꽃 종자 발아 및 유근 발달에 미치는 영향)

  • Kim, Tae Hyun;Kim, Do Hyun;Im, Hyeon Jeong;Choi, Kyu Seung;Kim, Sang Geun;Song, Chi Hyeon;Oh, Beom Seok;Kim, Yang Su;Song, Ki Seon;Won, Chang O
    • Proceedings of the Plant Resources Society of Korea Conference
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    • 2019.10a
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    • pp.39-39
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    • 2019
  • 섬초롱꽃은 울릉군에 한정적으로 분포하는 여러해살이풀이다. 산림청에서는 약관심종(LC) 등급의 희귀식물이자 특산식물로 분류하고 있으며, 꽃의 관상가치가 특히 높아 화단용 소재, 절화용, 화분재배 등으로 흔히 이용되고 있다. 따라서 본 연구는 섬초롱꽃의 대량증식 시, 중금속이 미칠 수 있는 영향에 대해 파악하고자 수행하였다. 실험에 사용한 중금속은 카드뮴(Cd), 철(Fe) 두 종류이며, 두 종류 모두 1% 한천(agar)배지에 10, 25, 50, 100, 200 mg/L 농도로 녹여 사용하였다. 발아율 및 유근 생장을 위해 종자 및 유묘를 치상 후, $25^{\circ}C$ 항온 생장상에서 발아율 및 유근 발달을 관찰하였다. 발아율 측정결과, 아무처리도하지 않은 1% 한천(agar) 배지에서 $62.7{\pm}7.4%$로 가장 높았고 중금속 농도가 높아질수록 감소하였다. 카드뮴(Cd) 처리구에서는 10, 25, 50, 100, 200 mg/L 농도에서 각각 $17.3{\pm}1.3$, $2.7{\pm}1.3$, $1.3{\pm}1.3$, 0, 0%로 나타났다. 한편, 철(Fe) 처리구에서는 10, 25, 50, 100, 200 mg/L 농도에서 각각 $46.7{\pm}4.8$, $24.0{\pm}2.3$, $36.0{\pm}6.9$, $20.0{\pm}2.3$, 0%로 나타났다. 유근의 평균 생장 길이(mm)는 아무처리도 하지 않은 1% 한천(agar) 배지에서 19.6 mm로 가장 높았고, 중금속 농도가 높아질수록 낮게 나타났다. 카드뮴(Cd) 처리구에서는 10, 25, 50, 100, 200 mg/L 농도에서 각각 4.6 mm, 1.9 mm, 0.7 mm, 0.9 mm, 0 mm 생장한 것으로 나타났다. 한편, 철(Fe) 처리구에서는 10, 25, 50, 100, 200 mg/L 농도에서 각각 15.9 mm, 8.6 mm, 8.1 mm, 0.9 mm, 0 mm 생장한 것으로 나타났다. 실험결과를 종합해 볼 때, 섬초롱꽃 종자 발아 및 유근 생장의 억제는 카드뮴(Cd) 처리구에서 높게 나타났고, 철(Fe) 처리구에서는 비교적 영향을 덜 미치는 것으로 나타났다. 특히 카드뮴은 10 mg/L 농도만 처리하더라도 약 3.6~4.2배의 발아율 생장율 감소가 나타나, 섬초롱꽃 대량증식 시, 치명적일 것으로 판단된다. 본 실험의 결과는 섬초롱꽃 종자를 이용한 대량증식 및 유묘재배에 있어, 토양을 선택하는데 중요한 기초자료로서 활용될 것으로 기대된다.

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Isolation and Characterization of Marine Bacterial Strain SH-1 Producing Agar-Degrading Enzymes (한천 분해효소를 생산하는 해양 미생물 SH-1의 분리 및 특성 분석)

  • Lee, Jae-Hag;Lee, Soon-Youl
    • Microbiology and Biotechnology Letters
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    • v.42 no.4
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    • pp.324-330
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    • 2014
  • A marine bacterial strain producing agar-degrading enzymes was isolated from a mud flat in Jeboo-do (Korea) using a selective artificial sea water (ASW) agar plate containing agar as the sole carbon source. The isolate, designated as SH-1, was gram-negative, aerobic, and motile with single polar flagellum. 16S rRNA gene sequence similarity analysis showed the isolate SH-1 had the highest homology (96.5%) to marine bacterium Neiella marina J221. Cells could grow at $28-37^{\circ}C$ but not at $42^{\circ}C$, and the agarase activity of the cell culture supernatant was higher when grown at $28^{\circ}C$ than when grown at $37^{\circ}C$. Cells could grow when concentrations of 1-5% (w/v) NaCl were added to the growth media with the best growth observed at 3% NaCl, and the agardegrading enzyme activity of the cell culture supernatant was best when grown at 3% NaCl-containing growth media under the conditions we examined. The crude enzyme prepared from 48-h culture broth of strain SH-1 exhibited an optimum pH and temperature for agar-degrading activity at 7.0 and $40^{\circ}C$, respectively. Zymogram analysis of the crude supernatant and cell extract showed that strain SH-1 produced at least 3 agar-degrading enzymes with molecular weights of 15, 35, and 52 KD. Thinlayer chromatography (TLC) analysis also suggested that HS-1 produces ${\beta}$-agarase to degrade agarose to neoagarooligosaccharides.

Effect of Plant Growth Regulators, Media and Celling Agents on In Vitro Microtuber Production of Pinellia ternata Breit (1식물생장조절제, 배지와 고형지지물이 반하의 기내 소괴경 생산에 미치는 영향)

  • Kim, Yong-Kyung;Lee, Ji-Yeon;Kim, Eung-Hwi;Cho, Dong-Ha;Park, Sang-Un
    • Korean Journal of Medicinal Crop Science
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    • v.15 no.3
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    • pp.210-214
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    • 2007
  • The study was carried out to establish in vitro microtuber production from leaf and petiole explant cultures of Pinellia ternata. Culture conditions were optimized by investigating the effect of plant growth regulators, different media, and gelling agents on the efficiency of microtuber indurtion. Among the different combinations of plant growth regulators tested, the combination of 0.1 mg/l 2,4-Dichlorophenoxyacetic (2,4-D) and 0.5 mg/l 6-benzylaminopurine (BAP) showed the highest yield fer microtuber production from leaf (3.9) and petiole (4.7) explant culture on MS medium far 6 weeks. SH(Schenk and Hildebrandt) medium was the most effective medium for microtuber induction and the half strength SH medium was better than SH medium for microtuber production from both leaf and petiole culture. Gelrite was better than agar in the formation of microtubers and 4% Gelrite showed the highest number of microtubers per explant frome leaf (5.9) and petiole (7.8) culture. Germination rate of microtubers after cold storaged for one months long was 86% from in vitro culture and 43% from autoclaved soil.

Occurrence of Syzygites Megalocarpus on Wild Mushrooms and Its Cultural Characteristics (야생(野生)버섯의 기생균(寄生菌)인 이분지털곰팡이의 출현(出現)과 배양(培養) 특성(特性))

  • Ka, Kang-Hyeon;Park, Hyun;Yoon, Kab-Hee;Bak, Won-Chull
    • Journal of Korean Society of Forest Science
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    • v.89 no.5
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    • pp.691-696
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    • 2000
  • Syzygites megalocarpus occurred on the fruit bodies of Tricholoma matsutake, Leccinum rugosiceps, Pulveroboletus ravenelii, Russula emetica, and Amanita pseudoporphyria in the field. We could select Malt Extract Agar, Mueller Hinton Medium and Potato Dextrose Agar as optimal media among eight media. Syzygites megalocarpus showed an optimal temperature around $23^{\circ}C$ with optimal pH 6.0. Growth of S. megalocarpus on PDA was inhibited by 36.5% at 5% NaCl compared with without NaCl and did not grow at more than 8% NaCl in 2 days after inoculation. However, it grew 1.1 cm in 10% NaCl in 5 days after inoculation. Growth of Tricholoma matsutake on PDA was inhibited by increasing contration of NaCl and did not nearly grow at 2.5% NaCl in 60 days after inoculation. Because S. megalocarpus grew at high concentration of NaCl, we concluded that NaCl should not use for controlling S. megalocarpus on the fruit body of T. matsutake.

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Development of a Quantitative Induction Method for Chondromyces crocatus Fruiting Body Formation (Chondromyces crocatus 자실체 형성의 정량적 유도 방법 개발)

  • Lee, Chayul;Shin, Hyejin;Cho, Kungyun
    • Korean Journal of Microbiology
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    • v.50 no.3
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    • pp.173-178
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    • 2014
  • We have developed a method for the preparation of dispersed cell suspensions of Chondromyces crocatus, which is essential for quantitative studies of fruiting body formation. Cells of C. crocatus have a tendency to aggregate in liquid, hindering quantitative studies. However, cells grown on casitone-yeast extract agar plates, containing 3% agar, allowed the preparation of well-dispersed cell suspensions. Cell suspensions at a concentration of $2{\times}10^8cells/ml$, obtained by using this method, developed typical C. crocatus fruiting bodies when placed as $20{\mu}l$ spots on agar plates with no nutrient supplementation. The addition of nutrients such as casitone altered or inhibited fruiting body formation. Fruiting body branch formation increased with increasing agar content. Under optimum conditions, the formation of fruiting body structure in C. crocatus KYC2823 was completed within 24 h.

Effects of Temperature, Relative Humidity, pH and Triazole Fungicides on Sporulation anc Conidial Germination of Uncinula necator (포도 흰가루병균(Uncinula necator)의 분생포자 형성과 발아에 미치는 온도, 습도, pH 및 Trizole 살균제의 영향)

  • Oh, Jeung-Haing
    • Korean Journal Plant Pathology
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    • v.13 no.4
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    • pp.210-214
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    • 1997
  • The experiment was conducted to obtain basic informations on the effects of key environments and fungicides on the sporulation, conidial germination and hitial growth of the hyphae of grape powdery mildew fungus Uncinula necator. Maximum sporulation occurred at RH 75~96% in vitro adiusted with sulfuric acid solution. Conidial germination and initial growth of the hyphae were better at 5% water agar than distilled water, and best at $26^{\circ}C$ and pH 5.0 of the substrates. Germination occurred equally well at light intensity of below 100 lux or dark condition, which was better at water agar supplemented with leaf extract 30% than pure water agar. The water agar supplemented with triazole fungicides reduced conidial germinations and initial growth of the hyphae signifcantly, in proportion to the increase in concentration of the fungicides, but the maguitude of reduction depended on the fungicides. Particularly in myclobutanil, reduction rate was very low as increased in concentration.

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Extraction Yield and Quality Attributes of Agar from Imported Seaweeds According to Various Pretreatments (수입원조(輸入原藻)의 전처리(前處理)과정에 따른 한천(寒天)의 수율(輸率) 및 품질특성(品質特性))

  • Cho, Han-Ok;Chung, Man-Jai;Lee, Su-Rae
    • Korean Journal of Food Science and Technology
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    • v.7 no.3
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    • pp.115-119
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    • 1975
  • Imported seaweeds Gracilaria sp. and Gelidium sp. from the Philippines and Gracilaria sp. from Brazil were subjected to the examination of yield and quality of agar according to various pretreatment conditions. As pretreatment condition for alkali-treated Gracilaria sp. from the Philippines, $0.05{\sim}0.1%$ concentration of sulfuric acid was proper to obtain the higher yield of agar for which a reverse proportionality was shown between the acid concentration and the strength of extraction condition. Highest yield from Gelidium sp. from the Philippines was obtained by pretreating with 5% sodium hydroxide at $90^{\circ}C$ for one hour, followed by 0.1% sulfuric acid treatment. Gracilaria sp. from Brazil gave the highest yield of agar by pretreatments with 1% sodium hydroxide followed by 0.05% sulfuric acid, both at room temperature for one hour. Acid treatment of alkali-treated Gracilaria sp. from the Philippines brought about the decrease of total nitrogen, total sulfur and crude ash, the increase of jelly strength and no marked change in gelation point and gelation ability. In general, acid-treatment conditions to give rise to high yield of agar improved the quality of product.

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The Effects of Addition of Agar on the Texture Characteristics (한천을 이용한 복숭아 젤리의 질감 특성과 기호도)

  • 박금순;조재욱
    • The Korean Journal of Food And Nutrition
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    • v.11 no.1
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    • pp.61-67
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    • 1998
  • Effects of various jelly prepared with different concentrations of agar and sugars on overall acceptability of the peach jelly were investigated. The preparations of peach for experimental jelly were carried by the mixture of peach pulp and juice(MPJ), and the extract form peach(EP). The results were summarized as follows ; 1. The pH for MPJ and EP were 3.95 to 4/31, respectively, and the brix degree were 13.0% and 11.5%, respectively. 2. The jelly prepared with MPJ added 3% agar and 30% sugar were most effective in appearance, hardness, springiness and overall acceptability. The relation of samples(P<0.001) was found to be significant. On the other hand, the jelly prepared with EP was higher scored than that with MPJ in overall acceptability, but there was no significant differences between samples. 3. The Hunter values of L*, a* and b* were the highest in both the jelly prepared with MPJ and that with EP, added 2% agar and 10% sugar. However, the L*, a* and b* values of the jelly added MPJ were higher than those of the sample added EP. 4. Texture and color scores of both the jelly added EP became higher as the concentrations of agar and sugars increased and there was significant differences between samples. 5. The relation between springiness and overall acceptability, and L* value of the jelly added MPJ showed negative at P<0.05 and that between springiness and overall acceptability of the jelly added EP also showed negative.

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