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Risk Analysis of Inorganic Arsenic in Foods (식품 중 무기비소의 위해 분석)

  • Yang, Seung-Hyun;Park, Ji-Su;Cho, Min-Ja;Choi, Hoon
    • Journal of Food Hygiene and Safety
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    • v.31 no.4
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    • pp.227-249
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    • 2016
  • Arsenic and its compounds vary in their toxicity according to the chemical forms. Inorganic arsenic is more toxic and known as carcinogen. The provisional tolerable weekly intake (PTWI) of $15{\mu}g/kg$ b.w./week established by the Joint FAO/WHO Expert Committee on Food Additives (JECFA) has been withdrawn, while the EFSA panel suggested $BMDL_{0.1}$ $0.3{\sim}8{\mu}g/kg\;b.w./day$ for cancers of the lung, skin and bladder, as well as skin lesions. Rice, seaweed and beverages are known as food being rich in inorganic arsenic. As(III) is the major form of inorganic arsenic in rice and anaerobic paddy soils, while most of inorganic arsenic in seaweed is present as As(V). The inorganic arsenic in food was extracted with solvent such as distilled water, methanol, nitric acid and so on in heat-assisted condition or at room temperature. Arsenic speciation analysis was based on ion-exchange chromatography and high-performance liquid chromatography equipped with atomic absorption spectrometry and inductively coupled plasma mass spectrometry. However, there has been no harmonized and standardized method for inorganic arsenic analysis internationally. The inorganic arsenic exposure from food has been estimated to range of $0.13{\sim}0.7{\mu}g/kg$ bw/day for European, American and Australian, and $0.22{\sim}5{\mu}g/kg$ bw/day for Asian. The maximum level (ML) for inorganic arsenic in food has established by EU, China, Australia and New Zealand, but are under review in Korea. Until now, several studies have conducted for reduction of inorganic arsenic in food. Inorganic arsenic levels in rice and seaweed were reduced by more polishing and washing, boiling and washing, respectively. Further research for international harmonization of analytical method, monitoring and risk assessment will be needed to strengthen safety management of inorganic arsenic of foods in Korea.

Continuous Wet Oxidation of TCE over Supported Metal Oxide Catalysts (금속산화물 담지촉매상에서 연속 습식 TCE 분해반응)

  • Kim, Moon Hyeon;Choo, Kwang-Ho
    • Korean Chemical Engineering Research
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    • v.43 no.2
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    • pp.206-214
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    • 2005
  • Heterogeneously-catalyzed oxidation of aqueous phase trichloroethylene (TCE) over supported metal oxides has been conducted to establish an approach to eliminate ppm levels of organic compounds in water. A continuous flow reactor system was designed to effect predominant reaction parameters in determining catalytic activity of the catalysts for wet TCE decomposition as a model reaction. 5 wt.% $CoO_x/TiO_2$ catalyst exhibited a transient period in activity vs. on-stream time behavior, suggesting that the surface structure of the $CoO_x$ might be altered with on-stream hours; regardless, it is probable to be the most promising catalyst. Not only could the bare support be inactive for the wet decomposition reaction at $36^{\circ}C$, but no TCE removal also occurred by the process of adsorption on $TiO_2$ surface. The catalytic activity was independent of all particle sizes used, thereby representing no mass transfer limitation in intraparticle diffusion. Very low TCE conversion appeared for $TiO_2$-supported $NiO_x$ and $CrO_x$ catalysts. Wet oxidation performance of supported Cu and Fe catalysts, obtained through an incipient wetness and ion exchange technique, was dependent primarily on the kinds of the metal oxides, in addition to the acidic solid supports and the preparation routes. 5 wt.% $FeO_x/TiO_2$ catalyst gave no activity in the oxidation reaction at $36^{\circ}C$, while 1.2 wt.% Fe-MFI was active for the wet decomposition depending on time on-stream. The noticeable difference in activity of the both catalysts suggests that the Fe oxidation states involved to catalytic redox cycle during the course of reaction play a significant role in catalyzing the wet decomposition as well as in maintaining the time on-stream activity. Based on the results of different $CoO_x$ loadings and reaction temperatures for the decomposition reaction at $36^{\circ}C$ with $CoO_x/TiO_2$, the catalyst possessed an optimal $CoO_x$ amount at which higher reaction temperatures facilitated the catalytic TCE conversion. Small amounts of the active ingredient could be dissolved by acidic leaching but such a process gave no appreciable activity loss of the $CoO_x$ catalyst.

Changes in Total Glucosinolates Levels and Physico-Chemical Properties of Kimchi using Korean Chinese Cabbage of Harvest Time according to Various Storage Conditions (수확기간별 배추를 이용한 김치의 저장조건에 따른 Total Glucosinolates 함량 및 이화학적 변화)

  • Jung, Ji-In;Hong, Eun-Young;Kim, Mee-Kyung;Jung, Ji-Won;Oh, Ji-Young;Kwon, Min-Soo;Lee, Kang-Pyo;Kim, Gun-Hee
    • Food Science and Preservation
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    • v.16 no.5
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    • pp.612-617
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    • 2009
  • Kimchi is a traditional pickled food using Korean Chinese cabbage(Brassica campestris var. pekinensis) and also containing phytochemicals, glucosinolates. This study was carried out to investigate the changes in the total glucosinolates levels of Kimchi using Korean Chinese cabbage of harvest time(June-July, August-September, October-November, December-April, May) according to storage temperature(4, 10, $15^{\circ}C$) and storage duration(0, 1, 3, 5, 7, 10, 14, 21 and 28 day). For determination of glucosinolates, 50g of Baechu kimchi was used for analytical sample preparation provided with an anion exchanges column and measured by UV-visible Spectrophotometer. The highest contents of water occurred at August-September during fermentation. At 15, 10, $4^{\circ}C$, the pH in all of seasonal variation of Baechu kimchi declined, especially from 0 to 3 days at $15^{\circ}C$, from 0 to 7 days at $10^{\circ}C$ and from 0 to 14 days at $4^{\circ}C$. At that storage, the total glucosinolates levels in all of seasonal variation of Kimchi declined in storage temperature. Baechu kimchi at August-September showed the highest total glucosinolates levels. Also total glucosinolates levels decreased as storage period increased. Baechu kimchi fermented at $15^{\circ}C$ for 7days decreased rapidly and reached to the lowest at the 1day(ranged from $10.3{\pm}0.70$ to $23.4{\pm}0.37{\mu}mol/g$ dry weight). At $10^{\circ}C$ for 14days were ranged from $12.9{\pm}0.29$ to $33.7{\pm}1.81{\mu}mol/g$ dry weight before fermentation and decreased rapidly at the 3day(ranged from $9.5{\pm}0.54$ to $20.5{\pm}0.61{\mu}mol/g$ dry weight). Total glucosinolates levels of Baechu kimchi fermented at $4^{\circ}C$ for 28days decreased rapidly during 7day(ranged from $9.9{\pm}0.78$ to $21.1{\pm}0.96{\mu}mol/g$ dry weight) and then slowly decreased. Therefore the total glucosinolates levels decreased during storage time and depended on harvest time and storage conditions of Kimchi.

Physico.chemical Properties of Inorganic Materials Currently Used as Root Medium Components for Crop Production in Korean Plant Factories (국내에서 식물공장용 배지 재료로 유통되는 무기물의 토양 물리화학적 특성)

  • Shin, Bo Kyoung;Son, Jung Eek;Choi, Jong Myung
    • Journal of Bio-Environment Control
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    • v.21 no.4
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    • pp.336-342
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    • 2012
  • Inorganic materials were commonly used as container media in domestic plant factories. Objective of this research was to secure the information in soil physical and chemical properties of inorganic materials such as vermiculites and perlites. To achieve this, 12 gold and silver vermiculites from China, Zimbabwe, and South Africa and 5 perlites from China were collected based on the marketing grades (MG) in particle sizes and analyzed for determination of their characteristics. The percentage of particles larger than $710{\mu}m$, in China perlite MG 3~5 mm, China silver vermiculites MG > 8 mm and MG 3~8 mm were 99.9%, 99.8%, and 99.7%, respectively, which were much higher than 28.4% in China gold vermiculite MG 0.3~1.0 mm, 14.0% in perlite MG < 1.0 mm, and 12.6% of Zimbabwe silver vermiculite MG < 1.0 mm. The container capacities of perlite MG < 1.0 mm and South Africa silver vermiculite MG 0.25~1.0 mm were 72.0% and 71.1%, respectively. The air space in China silver vermiculite MG 3~8 mm was 49.3% which was higher than other materials tested. However, the China gold and silver vermiculites MG 0.3~1 mm had 3.5% and 2.4% in air space indicating that possible problems could occur in soil aeration when they are used for container media. The percentage of easily available and buffering water of China gold vermiculite MG 0.3~1 mm and perlite MG < 1.0 mm were the highest among test materials. The ranges of pH and electrical conductivity were 6.36 to 10.7 and 0.032 to $0.393dS{\cdot}m^{-1}$ in vermiculites and 7.78 to 8.62 and 0.030 to $0.041dS{\cdot}m^{-1}$ in perlite, respectively. The cation exchange capacity of China silver vermiculite MG 0.3~1 mm were $14.7cmol{\cdot}kg^{-1}$ that was 10 times as high as $0.34cmol{\cdot}kg^{-1}$ in perlite MG 1~2.5 mm. The vermiculites had the higher contents of exchangeable cations such as Ca, K, and Na, than those of perlites.

Purification and Characterization of Sulfated Polysaccharide Isolated from Hot Water Extract of Pachymeniopsis elliptica (Pachymeniopsis elliptica의 열수 추출물로부터 분리한 함황 다당류의 정제 및 특성)

  • Lee, Sun-Hee;Jun, Woo-Jin;Yu, Kwang-Won;Chun, Hyug;Shin, Dong-Hoon;Hong, Bum-Shik;Cho, Hong-Yon;Yang, Han-Chul
    • Korean Journal of Food Science and Technology
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    • v.32 no.5
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    • pp.1191-1197
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    • 2000
  • In the preliminary study, we investigated the anti-complementary activities of 62 extracts from Korean edible seaweeds. Of those, Pachymeniopsis elliptica showed the highest anti-complementary activity. Therefore, it was purified as follows; i) PE-1 by ethanol precipitation, ii) PE-1-C by ultrafiltration, iii) PE-1-CIV by DEAE-Toyopearl 650C, and iv) PE-1-CIV-ii by Sepharose CL-6B. The purified compound, PE-1-CIV-ii, was the complexed homogeneous polysaccharide (molecular mass: 780 kDa) with 82.9% of anti-complementary activity. Also, it contained a significant amount of sulfate group (30.5%), which indicated it as a sulfated algal polysaccharide. Its structural monosaccharides were galactose (44.3%), 3,6-anhydrogalactose (34.0%), glucose (8.2%), fucose (5.4%), xylose (5.2%) and rhamnose (2.9%). After the treatment of periodate on a sample, a significant decrease in anti-complementary activity was found, which was a characteristic of bioactive polysaccharides. And-tumor activity of PE-1-A, B and C was tested in the sarcoma-180 solid tumor model. The PE-1-C with the largest molecular mass (more than 300 kDa) showed 81% of inhibition on the solid tumors, suggesting that the anti-complementary activity was, at least in part, related to anti-tumor activity. Based upon these results, the purified polysacchardes could be an immunopotentiator in vivo.

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Hydrogeochemical Characterization of Groundwater in Jeju Island using Principal Component Analysis and Geostatistics (주성분분석과 지구통계법을 이용한 제주도 지하수의 수리지화학 특성 연구)

  • Ko Kyung-Seok;Kim Yongie;Koh Dong-Chan;Lee Kwang-Sik;Lee Seung-Gu;Kang Cheol-Hee;Seong Hyun-Jeong;Park Won-Bae
    • Economic and Environmental Geology
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    • v.38 no.4 s.173
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    • pp.435-450
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    • 2005
  • The purpose of the study is to analyze the hydrogeochemical characteristics by multivariate statistical method, to interpret the hydrogeochemical processes for the new variables calculated from principal components analysis (PCA), and to infer the groundwater flow and circulation mechanism by applying the geostatistical methods for each element and principal component. Chloride and nitrate are the most influencing components for groundwater quality, and the contents of $NO_3$ increased by the input of agricultural activities show the largest variation. The results of PCA, a multivariate statistical method, show that the first three principal components explain $73.9\%$ of the total variance. PC1 indicates the increase of dissolved ions, PC2 is related with the dissolution of carbonate minerals and nitrate contamination, and PC3 shows the effect of cation exchange process and silicate mineral dissolution. From the results of experimental semivariogram, the components of groundwater are divided into two groups: one group includes electrical conductivity (EC), Cl, Na, and $NO_3$, and the other includes $HCO_3,\;SiO_2,$ Ca, and Sr. The results for spatial distribution of groundwater components showed that EC, Cl, and Na increased with approaching the coastal line and nitrate has close relationship with the presence of agricultural land. These components are also correlated with the topographic features reflecting the groundwater recharge effect. The kriging analysis by using principal components shows that PC 1 has the different spatial distribution of Cl, Na, and EC, possibly due to the influence of pH, Ca, Sr, and $HCO_3$ for PC1. It was considered that the linear anomaly zone of PC2 in western area was caused by the dissolution of carbonate mineral. Consequently, the application of multivariate and geostatistical methods for groundwater in the study area is very useful for determining the quantitative analysis of water quality data and the characteristics of spatial distribution.

Fertility Status in Northeastern Alpine Soils of South Korea with Cultivation of Vegetable Crops (강원도 고랭지 채소 재배지의 토양 비옥도관리 현황과 전망)

  • Yang, Jae-E.;Cho, Byong-Ok;Shin, Young-Oh;Kim, Jeong-Je
    • Korean Journal of Soil Science and Fertilizer
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    • v.34 no.1
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    • pp.1-7
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    • 2001
  • Total upland area for cultivating the vegetable crops in the Alpine soils of Northeastern South Korea has been extending its limit to meet the increasing demand of vegetable food in recent decades. About 70% of these alpine soils are located in over 7% of the slope and most of vegetable crops have been cultivated intensively without practicing the best management systems. Thus, soil erosion and continuous cropping system have degenerated the soil fertility and shown detrimental effects on water quality. We initiated an intensive and extensive investigation to characterize the fertility problems encountered in these uplands. Objectives of this paper were to characterize the fertility status in the Alpine soils cultivated with vegetable crops for many years and to provide the recommendations for adequate soil management measures including fertilization and erosion control. Soils in general have good drainage with textural classes of loam or sandy loam. Their topographical characteristics tended to lead them to shallow plow layers, and the steepness of the terrain created erosion hazard. Of the soils examined, about 11% of uplands over 30% gradient was found in need of an urgent reforestation. A high content of gravel and firm hardness of soil attributed to inhibit the utilization of farm machinery and plant-root development. The average soil pH 5.6 was slightly low relative to pH 5.70 of the national average. Organic matter content was high compared with 2.0% of national average, but decreased with the prolonged cultivation periods. Available $P_2O_5$ concentration was unusually high due to the consequence of over dose application with chemical and organic fertilizers. Exchangeable cations as Ca, Mg, and K were appeared to be decreased in these regions with prolonging the cultivation periods. There were no significant differences in cation exchange capacity (CEC) and electrical conductivity (EC) among locations. Heavy metal contents were mostly lower than the threshold of danger level designated by Soil Environment Conservation Law of South Korea. Results indicated that a proper countermeasure and the best management practice should be immediately implemented to conserve the top soil and fertility in the Alpine regions.

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The Concept of 'the Former World and the Later World' in Daesoon Thought as Introduced via the Diagrams of The Comprehensive Mirror of Taegeukdo (『태극도통감』의 도상을 통해 본 대순사상의 '선·후천' 개념)

  • Lee Bong-ho
    • Journal of the Daesoon Academy of Sciences
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    • v.47
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    • pp.65-103
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    • 2023
  • In The Canonical Scripture (典經), the core scripture of Daesoon Thought, the Former World and the Later World are divided into the Era of Mutual Contention and the Era of Mutual Beneficence. This concept of the Former World and the Later World appears in diagrams on I-Ching Studies (易學) in the text titled, The Comprehensive Mirror of Taegeukdo (太極道通鑑). In I-Ching Studies, Anterior Heaven (先天) and Posterior Heaven (後天) are the main concepts in Song Dynasty diagram books on I-Ching Studies. Among the diagrams of I-Ching Studies, Fuxi's Diagram of the Sequence of the Eight Trigrams, Fuxi's Diagram of the Positions of the Eight Trigrams, Fuxi's Diagram of the Sequence of the 64 Hexagrams, and Fuxi's Diagram of the Positions of the 64 Hexagrams correspond to the Anterior Heaven, and King Wen's Diagram of the Sequence of the Eight Trigrams and King Wen's Diagram of the Positions of the Eight Trigrams correspond to Posterior Heaven. In The Comprehensive Mirror of Taegeukdo, the diagrams of I-Ching Studies are reinterpreted according to Daesoon Thought. The Diagram of the Eight Trigrams of King Wen's Era corresponds to King Wen's Diagram of the Eight Trigrams in I-Ching Studies. This diagram was drawn according to the text in Chapter Five of the Treatise of Remarks on the Trigrams. This diagram corresponds to "the Era of the Nobility of Earth (地尊時代)" centered on the trigram kun (坤 / ☷ ground). Fuxi's Diagram of the Positions of the Eight Trigrams in I-Ching Studies corresponds to The Diagram of the Positions of the Eight Trigrams of Fuxi's Era in Daesoon Thought. The most significant feature of this diagram is that the trigrams assigned to the directions of north and south match the hexagram indicating the obstruction of Heaven and Earth. This is hexagram 12 (否), meaning "obstruction," and it depicts no exchange or communication between Yin and Yang. Naturally, this symbolizes mutual destruction overtaking Yin and Yang. Daesoon Thought expresses this as "the Era of the Nobility of Heaven (天尊時代)." The most significant feature of The Diagram of the Eight Trigrams of the Corrected Book of Changes in The Comprehensive Mirror of Taegeukdo is that the trigrams assigned to the directions of south and north are indicative of hexagram 11, Peace on Earth and in Heaven (泰). This is a diagram in which mutual destruction is resolved through the Five Phases because the trigrams for water (坎 / ☵) and fire (離 / ☲) are in a corrected orientation. Therefore, this diagram symbolizes a world "free from Mutual Contention" and "the Era of Human Nobility (人尊時代)." According to the contents of The Canonical Scripture, the Supreme God performed the Reordering Works of the Three Realms to correct the Mutual Contention of the Former World, and as a result, the Mutual Contention of the Former World will give way to the implementation of the Dao of Mutual Beneficence. The Supreme God's Reordering Works of the Three Realms have been completed in the realm of divine beings, but in the Later World, they appear as an Earthly Paradise where the Dao of Mutual Beneficence is realized. The diagram depicting the Later World is The Diagram of the Eight Trigrams of the Era of the Corrected Book of Changes in The Comprehensive Mirror of Taegeukdo.

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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