• Title/Summary/Keyword: Optimum Concentration

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Comparison of Measured and Calculated Carboxylation Rate, Electron Transfer Rate and Photosynthesis Rate Response to Different Light Intensity and Leaf Temperature in Semi-closed Greenhouse with Carbon Dioxide Fertilization for Tomato Cultivation (반밀폐형 온실 내에서 탄산가스 시비에 따른 광강도와 엽온에 반응한 토마토 잎의 최대 카복실화율, 전자전달율 및 광합성율 실측값과 모델링 방정식에 의한 예측값의 비교)

  • Choi, Eun-Young;Jeong, Young-Ae;An, Seung-Hyun;Jang, Dong-Cheol;Kim, Dae-Hyun;Lee, Dong-Soo;Kwon, Jin-Kyung;Woo, Young-Hoe
    • Journal of Bio-Environment Control
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    • v.30 no.4
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    • pp.401-409
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    • 2021
  • This study aimed to estimate the photosynthetic capacity of tomato plants grown in a semi-closed greenhouse using temperature response models of plant photosynthesis by calculating the ribulose 1,5-bisphosphate carboxylase/oxygenase maximum carboxylation rate (Vcmax), maximum electron transport rate (Jmax), thermal breakdown (high-temperature inhibition), and leaf respiration to predict the optimal conditions of the CO2-controlled greenhouse, for maximizing the photosynthetic rate. Gas exchange measurements for the A-Ci curve response to CO2 level with different light intensities {PAR (Photosynthetically Active Radiation) 200µmol·m-2·s-1 to 1500µmol·m-2·s-1} and leaf temperatures (20℃ to 35℃) were conducted with a portable infrared gas analyzer system. Arrhenius function, net CO2 assimilation (An), thermal breakdown, and daylight leaf respiration (Rd) were also calculated using the modeling equation. Estimated Jmax, An, Arrhenius function value, and thermal breakdown decreased in response to increased leaf temperature (> 30℃), and the optimum leaf temperature for the estimated Jmax was 30℃. The CO2 saturation point of the fifth leaf from the apical region was reached at 600ppm for 200 and 400µmol·m-2·s-1 of PAR, at 800ppm for 600 and 800µmol·m-2·s-1 of PAR, at 1000ppm for 1000µmol of PAR, and at 1500ppm for 1200 and 1500µmol·m-2·s-1 of PAR levels. The results suggest that the optimal conditions of CO2 concentration can be determined, using the photosynthetic model equation, to improve the photosynthetic rates of fruit vegetables grown in greenhouses.

In vitro micropropagation of M.26 (Malus pumila Mill) apple rootstock and assessment of the genetic diversity of proliferated plantlets using simple sequence repeat markers (사과 대목 M.26 (Malus pumila Mill)의 기내 대량번식 및 simple sequence repeat 마커를 이용한 증식된 식물체의 유전적 다양성 평가)

  • Cho, Kang Hee;Han, Bong Hee;Han, Jeom Hwa;Park, Seo Jun;Kim, Se Hee;Lee, Han Chan;Kim, Mi Young;Kim, Myung-Su
    • Journal of Plant Biotechnology
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    • v.45 no.4
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    • pp.382-391
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    • 2018
  • The objective of this study was to determine the most effective medium condition of shoot proliferation and root formation for the efficient in vitro micropropagation of M.26 (Malus pumila Mill). Simple sequence repeat (SSR) markers were used to analyze the genetic diversity of micro-propagated and greenhouse grown M.26. Shoot proliferation was carried out in MS (Murashige and Skoog) containing benzyladenin (BA, $0.5{\sim}5.0mg{\cdot}L^{-1}$) and thidiazuron (TDZ, $0.01{\sim}0.1mg{\cdot}L^{-1}$). The highest number of shoots (10.67 shoots per explant) was induced by adding BA at a concentration $1.0mg{\cdot}L^{-1}$. TDZ treatments caused higher hyperhydricity rate in cultured explants than in BA treatments. There was no significant effect of both BA and auxin on shoot proliferation, and the optimum proliferation medium for M.26 was MS medium containing $1.0mg{\cdot}L^{-1}$ BA. To find a suitable medium composition for shoot rooting, we tested different concentrations indole-3-butyric acid (IBA) and ${\alpha}$-naphthaleneacetic acid ($0.5{\sim}5.0mg{\cdot}L^{-1}$), MS medium (1/4-1), sucrose ($0{\sim}30g{\cdot}L^{-1}$). The shoots showed good rooting on half-strength MS medium containing $1.0mg{\cdot}L^{-1}$ IBA and $15-20g{\cdot}L^{-1}$ sucrose. The rooting rate (100%), number of roots (10.45 ~ 13.60 roots per explant), root length (7.41 ~ 8.33 cm), and shoot length (4.93 ~ 5.38 cm) were good on this medium. Fifteen SSR primers were detected in a total of 30 alleles in 20 micro-propagated plantlets, all SSR profiles from micro-propagated plantlets were monomorphic and similar to greenhouse grown control plantlet M.26 plant. The results indicated that M.26 micro-propagated plantlets were genetically stable.

Optimization of Medium Components using Response Surface Methodology for Cost-effective Mannitol Production by Leuconostoc mesenteroides SRCM201425 (반응표면분석법을 이용한 Leuconostoc mesenteroides SRCM201425의 만니톨 생산배지 최적화)

  • Ha, Gwangsu;Shin, Su-Jin;Jeong, Seong-Yeop;Yang, HoYeon;Im, Sua;Heo, JuHee;Yang, Hee-Jong;Jeong, Do-Youn
    • Journal of Life Science
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    • v.29 no.8
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    • pp.861-870
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    • 2019
  • This study was undertaken to establish optimum medium compositions for cost-effective mannitol production by Leuconostoc mesenteroides SRCM201425 isolated from kimchi. L. mesenteroides SRCM21425 from kimchi was selected for efficient mannitol production based on fructose analysis and identified by its 16S rRNA gene sequence, as well as by carbohydrate fermentation pattern analysis. To enhance mannitol production by L. mesenteroides SRCM201425, the effects of carbon, nitrogen, and mineral sources on mannitol production were first determined using Plackett-Burman design (PBD). The effects of 11 variables on mannitol production were investigated of which three variables, fructose, sucrose, and peptone, were selected. In the second step, each concentration of fructose, sucrose, and peptone was optimized using a central composite design (CCD) and response surface analysis. The predicted concentrations of fructose, sucrose, and peptone were 38.68 g/l, 30 g/l, and 39.67 g/l, respectively. The mathematical response model was reliable, with a coefficient of determination of $R^2=0.9185$. Mannitol production increased 20-fold as compared with the MRS medium, corresponding to a mannitol yield 97.46% when compared to MRS supplemented with 100 g/l of fructose in flask system. Furthermore, the production in the optimized medium was cost-effective. The findings of this study can be expected to be useful in biological production for catalytic hydrogenation causing byproduct and additional production costs.

Optimization and Scale-up of Fish Skin Peptide Loaded Liposome Preparation and Its Storage Stability (어피 펩타이드 리포좀 대량생산 최적 조건 및 저장 안정성)

  • Lee, JungGyu;Lee, YunJung;Bai, JingJing;Kim, Soojin;Cho, Youngjae;Choi, Mi-Jung
    • Food Engineering Progress
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    • v.21 no.4
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    • pp.360-366
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    • 2017
  • Fish skin peptide-loaded liposomes were prepared in 100 mL and 1 L solution as lab scales, and 10 L solution as a prototype scale. The particle size and zeta potential were measured to determine the optimal conditions for the production of fish skin peptide-loaded liposome. The liposome was manufactured by the following conditions: (1) primary homogenization at 4,000 rpm, 8,000 rpm, and 12,000 rpm for 3 minutes; (2) secondary homogenization at 40 watt (W), 60 W, and 80 W for 3 minutes. From this experimental design, the optimal conditions of homogenization were selected as 4,000 rpm and 60 W. For the next step, fish peptides were prepared as the concentrations of 3, 6, and 12% at the optimum manufacturing conditions of liposome and stored at $4^{\circ}C$. Particle size, polydispersion index (pdI), and zeta potential of peptide-loaded liposome were measured for its stability. Particle size increased significantly as manufacture scale and peptide concentration increased, and decreased over storage time. The zeta potential results increased as storage time increased at 10 L scale. In addition, 12% peptide showed the formation of a sediment layer after 3 weeks, and 6% peptide was considered to be the most suitable for industrial application.

Design of a Dual Band-pass Filter Using Fork-type Open Stubs and SIR Structure (포크 형태의 개방형 스터브 및 SIR 구조를 이용한 이중대역 대역통과 여파기의 설계)

  • Tae-Hyeon Lee
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.22 no.1
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    • pp.252-264
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    • 2023
  • This paper proposes a design of a dual-band band-pass filter that integrates a λg/2 open SIR structure, a transmission line, and a fork-type structure with symmetric and asymmetric open stubs. To obtain the dual-band effect, the proposed filter uses the SIR structure and adjusts the impedance ratio of the SIR structure. Therefore, the position of the harmonics of the filter is shifted through the adjustment of the impedance ratio, and this can obtain a double-band effect. In order to obtain the dual-band characteristics, the dual-band effect is obtained by inserting a open stub between the SIR structures with the SIR structure divided in half. In addition, the second frequency response is obtained by adjusting the length of the open symmetrical stub in the fork-shaped structure. The asymmetrical open stub in the fork form achieves optimum bandwidth by adjusting the length. Therefore, the first center frequency of the proposed band-pass filter is 5.896 GHz and the bandwidth is 13.6 %. At this time, the measurement results are 0.13 dB and 33.6 dB. The second center frequency is 5.906 GHz and the bandwidth is 13.6 %. At this time, the measurement results are 0.15 dB and 19.8 dB. The reason is that when the impedance ratio (Δ) is higher than 1, the position of the harmonic is shifted to a lower frequency band. However, if the impedance ratio (Δ) is lowered by one step, the position of harmonics will move to a higher frequency band. The function of the filter designed using these characteristics can be obtained from the measurement result. The proposed band-pass filter has no coupling loss and no via energy concentration loss because there is no coupling structure of input/output and no via hole. Therefore, system integration is possible due to its excellent performance, and it is expected that dedicated short-range communication (DSRC) system applications used in traffic communication systems will be possible.

Optimum Strength and NH4+:NO3- Ratio of Nutrient Solution for Romaine Lettuce Cultivated in a Home Hydroponic System (가정용 수경재배기에서 재배한 로메인상추의 생육에 적합한 양액 강도와 NH4+:NO3-의 비율)

  • Kyungdeok Noh;Byoung Ryong Jeong
    • Journal of Bio-Environment Control
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    • v.32 no.2
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    • pp.97-105
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    • 2023
  • Concentration of nitrogen, one of the major elements, and ratio of two nitrogen forms (NH4+ and NO3-) in the nutrient solution affect the quality and food safety of fresh vegetable produce. This study was conducted to find an appropriate strength and NH4+:NO3- ratio of a nutrient solution for growth and development of a Romaine lettuce (Lactuca sativa L. var. longiflora) 'Caesar Green', a representative leafy vegetable, grown in a home hydroponic system. In the first experiment, plants were grown using three types of nutrient solution: A commercial nutrient solution (Peters) and two strengths (GNU1 and GNU2) of a multipurpose nutrient solution (GNU solution) developed in a Gyeongsang National University lab. Plants grown with the GNU1 and GNU2 had greater shoot length, leaf length and width, and biomass yield than Peters. On the other hand, the root hairs of plants grown with Peters were short and dark in color. Tissue NH4+ content in the Peters was higher than that of the GNU1 and GNU2. The higher contents of NH4+ in this solution may have caused ammonium toxicity. In the second experiment, eight treatment solutions, combining GNU1 and GNU2 solutions with four ratios of NO3- :NH4+ named as 1, 2, 3 and 4 were used. Both experiments showed more growth in the GNU2 group, which had a relatively low ionic strength of the nutrient solution. The growth of Romaine lettuce showed the greatest fresh weight along with low tissue NO3- content in the GNU2-2. This was more advantageous in terms of food safety in that it suppressed the accumulation of surplus NO3- in tissues due to the low ionic trength of the GNU2 subgroup. In addition, this is preferable in that it can reduce the absolute amount of the input of inorganic nutrients to the nutrient solution.

Seedling Age Effects on the Growth and Nutrient Uptake of Chamaecyparis obtusa Container Seedlings (편백 용기묘의 묘령에 따른 생장 및 양분 흡수 특성)

  • Deokgyo Jeong;Gyeongwon Baek;Choonsig Kim
    • Journal of Korean Society of Forest Science
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    • v.113 no.1
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    • pp.31-39
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    • 2024
  • This study was performed to determine the effects of Four seedling age classes ageon the characteristics of growth and nutrient uptake in Chamaecyparis obtusa container seedlings. Seedlings (1-1, 2-0, 2-1, and 2-2 seedlings) of C. obtusa grown in containers were harvested to measure specific leaf area, height (H)/root collar diameter (D) ratio, dry mass of aboveground (T)/root dry mass (R) ratio, and seedling quality index of seedlings. The specific leaf area was highest in 1-0 seedlings (30.48 cm2 g-1), whereas it decreased (from 28.62 cm2 g-1 to 23.59 cm2 g-1) with increasing seedling age. The H/D ratio increased with increasing seedling age (from 4.41 in 1-0 seedlings to 8.35 in 2-2 seedlings). The T/R ratio decreased as the seedling age increased (from 4.29 in the 1-0 seedling to 2.13 in the 2-1 seedling). The seedling quality index increased with increasing seedling age (from 0.10 for the 1-0 seedling to 3.06 for the 2-2 seedling). The carbon concentrations of seedling components (leaf, branches, stem, and roots) did not differ significantly with seedling age, whereas the nitrogen concentration of seedling components was the lowest in 2-1 seedlings, as no fertilizer was applied to discourage excessive growth of the seedlings. Phosphorus, potassium, and magnesium concentrations in 2-1 seedling components were not affected by the lack of fertilizer application. These results can be applied to determine the optimum morphological characteristics and nutrient management by seedling age in container- grown C. obtusa.

Optimal Salt Concentration and Temperature for Perilla Seed Germination and Soil Bulk Density, Sowing Depth, and Salinity on Emergence Rate in Reclaimed Soil (들깨 NaCl 농도, 온도에 따른 발아와 간척지 토양에서 용적밀도, 파종깊이, 염농도에 따른 출현 특성)

  • Yang-Yeol Oh;Kwang Seung-Lee;Hee-Kyoung Ock;Hak-Seong Lee;Seo-Young Jung;Bo-Seong Seo;Young-Tae Shin;Kang-Ho Jung;Bang-Hun Kang;Hyun-Suk Jo;Su-Hwan Lee;Jin Jung;Seung-Yeon Kim;Jung-In Kim
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.68 no.4
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    • pp.413-421
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    • 2023
  • Data on salt tolerance, optimal sowing depth, soil bulk density (pb) and cardinal temperatures required for the germination and emergence of perilla (Perilla frutescens (L.) Britt) are scarce for reclaimed land soil. An experiment was conducted across six temperature treatments (10, 15, 20 , 25, 30, and 35℃) to determine the cardinal temperature for perilla seed germination and four salinity levels (0, 20, 40, and 60 mM) to determine the salt tolerance. Another experiment was performed for quantifying the emergence response of perilla to pb (1.1, 1.3, and 1.5 g cm-3), sowing depth (1, 2, 3, and 4 cm) and soil salinity. The results revealed that increased sodium chloride levels caused a significant reduction in the seed germination at Deulhyang and Sodam. The optimum upper limit temperature was less than 35℃. The optimal sowing depth and soil bulk density were 1 cm and 1.1 g cm-3 respectively. Perilla seedling growth was inhibited at 1.9 dS m-1 although varying responses were observed. These results aid our understanding of the germination and emergence rate of these crops and provide data for field cultivation to optimize crop sowing in reclaimed land.

Studies on Sclerotium rolfsii Sacc. isolated from Magnolia kobus DC. in Korea (목련(Magnolia kobus DC.)에서 분리한 흰비단병균(Sclerotium rolfsii Sacc.)에 관한 연구)

  • Kim Kichung
    • Korean journal of applied entomology
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    • v.13 no.3 s.20
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    • pp.105-133
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    • 1974
  • The present study is an attempt to solve the basic problems involved in the control of the Sclerotium disease. The biologic stranis of Sclerotium rolfsii Sacc., pathogen of Sclerotium disease of Magnolia kobus, were differentiated, and the effects of vitamins, various nitrogen and carbon sources on its mycelial growth and sclerotial production have been investigated. In addition the relationship between the cultural filtrate of Penicillium sp. and the growth of Sclerotium rolfsii, the tolerance of its mycelia or sclerotia to moist heat or drought and to Benlate (methyl-(butylcarbamoy 1)-2-benzimidazole carbamate), Tachigaren (3-hydroxy-5-methylisoxazole) and other chemicals were also clarified. The results are summarizee as follows: 1. There were two biologic strains, Type-l and Type-2 among isolates. They differed from each other in the mode of growth and colonial appearance on the media, aversion phenomenon and in their pathogenicity. These two types had similar pathogenicity to the Magnolia kobus and Robinia pseudoacasia, but behaved somewhat differently to the soybaen and cucumber, the Type-l being more virulent. 2. Except potassium nitrite, sodium nitrite and glycine, all of the 12 nitrogen sources tested were utilized for the mycelial growth and sclerotial production of this fungus when 10r/l of thiamine hydrochloride was added in the culture solution. Considering the forms of nitrogen, ammonium nitrogen was more available than nitrate nitrogen for the growth of mycelia, but nitrate nitrogen was better for sclerotia formation. Organic nitrogen showed different availabilities according to compounds used. While nitrite nitrogen was unavailable for both mycelial growth and sclerotial formation whether thiamine hydrochlioride was added or not. 3. Seven kinds of carbon sources examined were not effective in general, as long as thiamine hydrochloride was not added. When thiamine hydrochloride was added, glucose and saccharose exhibited mycelial growth, while rnaltose and soluble starch gave lesser, and xylose, lactose, and glycine showed no effect at all,. In the sclerotial production, all the tested carbon sources, except lactose, were effective, and glucose, maltose, saccharose, and soluble starch gave better results. 4. At the same level of nitrogen, the amount of mycelial growth increased as more carbon Sources were applied but decreased with the increase of nitrogen above 0.5g/1. The amount of sclerotial production decreased wi th the increase of carbon sources. 5. Sclerotium rolfsii was thiamine-defficient and required thiamine 20r/l for maximun growth of mycelia. At a higher concentration of more than 20r/l, however, mycelial growth decreased as the concentration increased, and was inhibited at l50r/l to such a degree of thiamine-free. 6. The effect of the nitrogen sources on the mycelial growth under the presence of thiamine were recognized in the decreasing order of $NH_4NO_3,\;(NH_4)_2SO_4,\;asparagine,\;KNO_3$, and their effects on the sclerotial production in the order of $KNO_3,\;NH_4NO_3,\;asparagine,\;(NH_4)_2SO_4$. The optimum concentration of thiamine was about 12r/l in $KNO_3$ and about 16r/l in asparagine for the growth of mycelia; about 8r/l in $KNO_3$ and $NH_4NO_3$, and 16r/l in asparagine for the production of sclerotia. 7. After the fungus started to grow, the pH value of cultural filtrate rapidly dropped to about 3.5. Hereafter, its rate slowed down as the growth amount increased and did not depreciated below pH2.2. 8. The role of thiamine in the growth of the organism was vital. If thiamine was not added, the combination of biotin, pyridoxine, and inositol did not show any effects on the growth of the organism at all. Equivalent or better mycelial growth was recognized in the combination of thiamine+pyridoxine, thiamine+inositol, thiamine+biotin+pyridoxine, and thiamine+biotin+pyridoxine+inositol, as compared with thiamine alone. In the combinations of thiamine+biotin and thiamine+biotin+inositol, mycelial growth was inhibited. Sclerotial production in dry weight increased more in these combinations than in the medium of thiamine alone. 9. The stimulating effects of the Penicillium cultural filtrate on the mycelial growth was noticed. It increased linearly with the increase of filtrate concentration up to 6-15 ml/50ml basal medium solution. 10. $NH_4NO_3$. as a nitrogen source for mycelial growth was more effective than asparasine regardless of the concentration of cultural filtrate. 11. In the series of fractionations of the cultural filtrate, mycelial growth occured in unvolatile, ether insoluble cation-adsorbed or anion-unadsorbed substance fractions among the fractions of volatile, unvolatile acids, ether soluble organic acids, ether insoluble, cation-adsorbed, cation-unadsorbed, anion-adsorbed and anion-unadsorbed. and anion-un-adsorbed substance tested. Sclerotia were produced only in cation-adsorbed fraction. 12. According to the above results, it was assumed that substances for the mycelial growth and sclerotial formation and inhibitor of sclerotial formation were include::! in cultural filtrate and they were quite different from each other. I was further assumed that the former two substances are un volatile, ether insotuble, and adsorbed to cation-exchange resin, but not adsorbed to anion, whereas the latter is unvolatile, ether insoluble, and not adsorbed to cation or anion-exchange resin. 13. Seven amino acids-aspartic acid, cystine, glysine, histidine, Iycine, tyrosine and dinitroaniline-were detected in the fractions adsorbed to cation-exchange resin by applying the paper chromatography improved with DNP-amino acids. 14. Mycelial growth or sclerotial production was not stimulated significantly by separate or combined application of glutamic acid, aspartic acid, cystine, histidine, and glysine. Tyrosine gave the stimulating effect when applied .alone and when combined with other amino acids in some cases. 15. The tolerance of sclerotia to moist heat varied according to their water content, that was, the dried sclerotia are more tolerant than wet ones. The sclerotia harvested directly from the media, both Type-1 and Type-2, lost viability within 5 minutes at $52^{\circ}C$. Sclerotia dried for 155 days at$26^{\circ}C$ had more tolerance: sclerotia of Type-l were killed in 15 mins. at $52^{\circ}C$ and in 5 mins. at $57^{\circ}C$, and sclerotia of Type-2 were killed in 10 mins. both at $52^{\circ}C$ or $57^{\circ}C$. 16. Cultural sclerotia of both strains maintained good germinability for 132 days at$26^{\circ}C$. Natural sclerotia of them stored for 283 days under air dry condition still had good germinability, even for 443 days: type-l and type-2 maintained $20\%$ and $26.9\%$ germinability, respectively. 17. The tolerance to low temperature increased in the order of mycelia, felts and sclerotia. Mycelia completely lost the ability to grow within 1 week at $7-8^{\circ}C$> below zero, while mycelial felts still maintained the viability after .3 weeks at $7-20^{\circ}C$ below zero, and sclerotia were even more tolerant. 18. Sclerotia of type-l and type-2 were killed when dipped into the $0.05\%$ solution of mercury chloride for 180 mins. and 240 mins. respectively: and in the $0.1\%$ solution, Type-l for 60 mins. and Type-2 for 30 mins. In the $0.125\%$ uspulun solution, Type-l sclerotia were killed in 180 mins., and those of Type-2 were killed for 90 mins. in the$0.125\%$solution. Dipping into the $5\%$ copper sulphate solution or $0.2\%$ solution of Ceresan lime or Mercron for 240 mins. failed to kill sclerotia of either Type-l or Type-2. 19. Inhibitory effect on mycelial growth of Benlate or Tachi-garen in the liquid culture increased as the concentration increased. 6 days after application, obvious inhibitory effects were found in all treatments except Benlate 0.5ppm; but after 12 days, distingushed diflerences were shown among the different concentrations. As compared with the control, mycelial growth was inhibited by $66\%$ at 0.5ppm and by $92\%$ at 2.0ppm of Benlate, and by$54\%$ at 1ppm and about $77\%$ at 1.5ppm or 2.0ppm of Tachigaren. The mycelial growth was inhibited completely at 500ppm of both fungicides, and the formation of sclerotia was checked at 1,000ppm of Benlate ant at 500ppm or 1,000ppm of Tachigaren. 20. Consumptions of glucose or ammonium nitrogen in the culture solution usually increased with the increment of mycelial growth, but when Benlate or Tachigaren were applied, consumptions of glucose or ammonium nitrogen were inhibited with the increment of concentration of the fungicides. At the low concentrations of Benlate (0.5ppm or 1ppm), however, ammonium nitrogen consumption was higher than that of the ontrol. 21. The amount of mycelia produced by consuming 1mg of glucose or ammonium nitrogen in the culture solution was lowered markedly by Benlate or Tachigaren. Such effects were the severest on the third day after their treatment in all concentrations, and then gradually recovered with the progress of time. 22. In the sand culture, mycelial growth was not inhibited. It was indirectly estimated by the amount of $CO_2$ evolved at any concentrations, except in the Tachigaren 100mg/g sand in which mycelial growth was inhibited significantly. Sclerotial production was completely depressed in the 10mg/g sand of Benlate or Tachigaren. 23. There was no visible inhibitory effect on the germination of sclerotia when the sclerotia were dipped in the solution 0.1, 1.0, 100, 1.000ppm of Benlate or Tachigaren for 10 minutes or even 20 minutes.

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Studies on the Physical and Chemical Denatures of Cocoon Bave Sericin throughout Silk Filature Processes (제사과정 전후에서의 견사세리신의 물리화학적 성질변화에 관한 연구)

  • 남중희
    • Journal of Sericultural and Entomological Science
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    • v.16 no.1
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    • pp.21-48
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    • 1974
  • The studies were carried out to disclose the physical and chemical properties of sericin fraction obtained from silk cocoon shells and its characteristics of swelling and solubility. The following results were obtained. 1. The physical and chemical properties of sericin fraction. 1) In contrast to the easy water soluble sericin, the hard soluble sericin contains fewer amino acids include of polar side radical while the hard soluble amino acid sach as alanine and leucine were detected. 2) The easy soluble amino acids were found mainly on the outer part of the fibroin, but the hard soluble amino acids were located in the near parts to the fibroin. 3) The swelling and solubility of the sericin could be hardly assayed by the analysis of the amino acid composition, and could be considered to tee closely related to the compound of the sericin crystal and secondary structure. 4) The X-ray patterns of the cocoon filament were ring shape, but they disappeared by the degumming treatment. 5) The sericin of tussah silkworm (A. pernyi), showed stronger circular patterns in the meridian than the regular silkworm (Bombyx mori). 6) There was no pattern difference between Fraction A and B. 7) X-ray diffraction patterns of the Sericin 1, ll and 111 were similar except interference of 8.85A (side chain spacing). 8) The amino acids above 150 in molecular weight such as Cys. Tyr. Phe. His. and Arg. were not found quantitatively by the 60 minutes-hydrolysis (6N-HCI). 9) The X-ray Pattern of 4.6A had a tendency to disappear with hot-water, ether, and alcohol treatment. 10) The partial hydrolysis of sericin showed a cirucular interference (2A) on the meridian. 11) The sericin pellet after hydrolysis was considered to be peptides composed with specific amino acids. 12) The decomposing temperature of Sericin 111 was higher than that of Sericin I and II. 13) Thermogram of the inner portioned sericin of the cocoon shell had double endothermic peaks at 165$^{\circ}C$, and 245$^{\circ}C$, and its decomposing temperature was higher than that of other portioned sericin. 14) The infrared spectroscopic properties among sericin I, II, III and sericin extracted from each layer portion of the cocoon shell were similar. II. The characteristics of seriein swelling and solubility related with silk processing. 1) Fifteen minutes was required to dehydrate the free moisture of cocoon shells with centrifugal force controlled at 13${\times}$10$^4$ dyne/g at 3,000 R.P.M. B) It took 30 minutes for the sericin to show positive reaction with the Folin-Ciocaltue reagent at room temperature. 3) The measurable wave length of the visible radiation was 500-750m${\mu}$, and the highest absorbance was observed at the wave length of 650m${\mu}$. 4) The colorimetric analysis should be conducted at 650mu for low concentration (10$\mu\textrm{g}$/$m\ell$), and at 500m${\mu}$ for the higher concentration to obtain an exact analysis. 5) The absorbing curves of sericin and egg albumin at different wave lengths were similar, but the absorbance of the former was slightly higher than that of the latter. 6) The quantity of the sericin measured by the colorimetric analysis, turned out to be less than by the Kjeldahl method. 7) Both temperature and duration in the cocoon cooking process has much effect on the swelling and solubility of the cocoon shells, but the temperature was more influential than the duration of the treatment. 8) The factorial relation between the temperature and the duration of treatment of the cocoon cooking to check for siricin swelling and solubility showed that the treatment duration should be gradually increased to reach optimum swelling and solubility of sericin with low temperature(70$^{\circ}C$) . High temperature, however, showed more sharp increase. 9) The more increased temperature in the drying of fresh cocoons, the less the sericin swelling and solubility were obtained. 10) In a specific cooking duration, the heavier the cocoon shell is, the less the swelling and solubility were obtained. 11) It was considered that there are differences in swelling or solubility between the filaments of each cocoon layer. 12) Sericin swelling or solubility in the cocoon filament was decreased by the wax extraction.. 13) The ionic surface active agent accelerated the swelling and solubility of the sericin at the range of pH 6-7. 14) In the same conditions as above, the cation agent was absorbed into the sericin. 15) In case of the increase of Ca ang Mg in the reeling water, its pH value drifted toward the acidity. 16) A buffering action was observed between the sericin and the water hardness constituents in the reeling water. 17) The effect of calcium on the swelling and solubility of the sericin was more moderate than that of magnecium. 18) The solute of the water hardness constituents increased the electric conductivity in the reeling water.

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