• Applied Biological Chemistry
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• v.16 no.1
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• pp.1-11
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• 1973

In order to obtain the basic informations on the production of single cell protein from ethanol, 145 yeast strains utilizing ethanol as a sole carbon source were isolated from 32 soil samples in Korea. A yeast strain showing the highest cell yield among the isolated strains was selected and identified. The optimum culture condition, utilization of other carbon sources and the cultural characteristics for the selected yeast, and the chemical analysis of the yeast cell composition, and utilization of ethanol by the selected yeast were investigated. All the culture was carried out in the shaking flasks. The results obtained were as follows: 1. The selected yeast strain was identified as Debaryomyces nicotianae-SNU 72. 2. The optimum composition of the medium for the selected yeast is : Ethanol 40 ml, Urea 0.5 g, Potassium phosphate (dibasic) 0.5 g, Ammoium phosphate (monobasic) 0.15 g, Magnesium sulfate 0.05 g, Calcium chloride 0.01g, Yeast extract 0.005 g, Tap water 1000 ml. 3. The optimum pH was 5.0-5.5, the optimum temperature $30-33^{\circ}C$ and the aerobic state was unimportant. 4. Utilization of methanol, n-propanol, iso-propanol, n-butanol, iso-butanol, tert-amyl alcohol and acetic acid by the selected yeast was very weak. So substitution of the subtrate was thought to be impossible. 5. Studies on the propagation of the yeast cells showed that the lag phase of the yeast cells lasted 16 hours, and the logarithmic growth phase extended 16 to 28 hours. The specific growth rate was about $0.19\;hr^{-1}$ and the doubling time was 3.6 hours during the logarithmic growth phase. 6. As the result of the chemical analysis of the dry yeast cells, the content rate of the crude protein was 55.19 %, the content of others was similar to the average content of the yeast component. 7. After 34 hours cultivation, under the optimum culture condition investigated, the dry cell yield against the amount of the added ethanol was 53.4 % (W/V%), the dry cell yield against the amount of the utilized ethanol was 73.6 % (W/V%), the evaporation rate of ethanol was about 19.1 %.

• Applied Biological Chemistry
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• v.11
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• pp.35-41
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• 1969

In order to determine proper ratio of wheat to soybean of soysauce koji material for Korean people's taste, sensory evaluation for the soysauces made from soysauce kojis with various above-mentioned ratio and analysis of chemical components through the brewing period of six months were carried out. The results obtained were summarized as follows: 1. The specific gravity of all the soysauces increased gradually as the time passed and had maximum values in two months with nearly constant values thereafter. Concerning soybean/wheat-ratio, generally, the higher soybean/wheat-ratio, the lower specific gravity was observed but when this ratio was higher than 10 : 6, the gravity was on the similar levels. 2. The solid material in all the soysauces increased in the earlier stage and there were no significant differences among the treatments but soysauces without wheat had a little low content. 3. The lesser amount of wheat as raw material was, the higher contents of total nitrogen were and the contents of total nitrogen in the every ratio of raw material increased parallely as the mash ages. 4. The amino-nitrogen levels were found to have the simllar tendency to total nitroghen levels. 5. The reducing sugar content was higher in the soysauces with more-wheat and increased rapidly up to the maximum level in two months and then the higher wheat/soybean-ratio was, the slower decrease of the sugar content was observed. 6. The maximum total acidity was observed in the soysauces with 10; 4-6 (soybean/wheat-ratio) and increased similary in all the soysauces throughout the period. 7. According to the sensory evaluation, the short (2-3 months) fermented soysauces showed best taste when soybean/wheat-ratio was 10 : 8 and 10 : 6 if diluted, but in long (4-6 months) fermented soysauces it was 10 : 6 and 10 : 4 if diluted.

• Applied Biological Chemistry
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• v.11
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• pp.83-88
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• 1969

94 Cellulase producing strains were isoated from soils, composts, rotten woods and straws, and gastric contents and feces of herbivorous animals in various places. Among them, the strain MC-9, MC-10, MC-53 and MC-61 were found to be highly active in the degradation of carboxy methyl cellulose. Their cultural conditions adequate for the cellulase formation and effects of inorganic salts and various organic substances added to the wheat bran media were investigated. The results obtained are as follows; 1. Optimum conditions for the cellulase formation were MC-9: pH 5.5, temp. $35^{\circ}C$, incubation time 5 days, MC-10: pH 5.5-6.0, temp. $30^{\circ}C$, incubation time 5 days, MC-53: pH 3.5, temp. $30^{\circ}C$, incubation time 5 days, MC-61: pH 3.5-4.0, temp. 30-$35^{\circ}C$, incubation time 5 days. 2. Their cellulase activity in their optimum conditions were MC-9: CMC-LP(liquefying power). 87.7%, CMC-SP(saccharifying power) 3.20 glucose mg./gm. of the cultures/min., MC-10: CMC-LP 82.9%, CMC-SP 2.48 glucose mg./gm. of the cultures/min., MC-53: CMC-LP 72.4%, CMC-SP 1.76 glucose mg./gm. of the cultures/min., MC-61: CMC-LP 87.1%, CMC-SP 2.08 glucose mg./gm. of the cultures/min. 3. Additions of inorganic salts to the wheat bran media were not significant for the cellulase formation, but additions of soybean film and orange-peel pomace promoted the CMC-liquefying power 3 to 5 percent in wheat bran cultures of the strains.

• Applied Biological Chemistry
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• v.11
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• pp.173-184
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• 1969

To elucidate the effect of Amo-1618(4-hydroxyl-5-isopropyl-2-methlphenyl trimethyl ammonium chloride, 1-piperidine carboxylate) known as a kind of growth retardant, on the growth, grain yield, increasing the efficiency of nitrogen fertilizer, behavior of mineral nutritions and the rate of phosphorus utilization, this experiment was conducted pot culture method in a vinyl house. Two nitrogen level, namely, practical nitrogen level(1 N) and three times nitrogen level(3 N) was made and labelled double-calcium-superphosphate $Ca(H_2P^{32}O_4)_2.\;2H_2O)$ as a source of radioactive phosphorus(P-32) was employed $80\;{\mu}c/pot$, respectively. Rice seedlings, variety 'Suwon No. 82', was transplanted to a 1/50,000 a china pot on June 13 in 1968. For treatment, at early stage of tillering, 10,000 ppm solution of Amo-1618 was foliar sprayed only one time. The Duncan's new mutiple-range test was adopted for statistical analysis evaluating experimental data at 5% level significance. The results obtained may be summarized as follows; 1) No significant difference was found among the treatments in plant height, but in plot of Amo-1618 treatment and 3 N level, number of tillers was significantly increased than that of others. 2) Weight of 10,000 kernels and seed-setting rate was also remarkably increased in same treatment above. 3) Grain yield per pot was significantly increased in Amo-1618 and 3 N level application. This results seemed to be due to the increased the factors on the yield. 4) Contents of nitrogen and phosphorus per cent in the grain was likewise increased in Amo-1618 and 3 N application. There is, however, no difference among treatments in the content of nitrogen and phosphorus in the leaves and culms of rice plants. 5) On the other hand, the contents of potassium and magnesium, no distinctly tendeny showed among treatments. 6) The rate of phosphorus utilization was significantly increased in the plot of Amo-1618 and 3 N application.

• Applied Biological Chemistry
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• v.22 no.2
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• pp.109-122
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• 1979

Present study was carried out to reduce residual toxicity of BHC insecticides inherent in the organochlorine pesticides. For This end, r-isomer, the most potent insecticidal component among the BHC stereoisomers, was isolated and thus fortified by means of solvent precipitation. In parallel, 3-(2,4,5-trichlorophenyl)-1-methyl urea was prepared in good yield from technical BHC via 1,2,4-trichlorobenzene, 1,2,4,-trichloronitrobenzene, and 2,4,5-trichloroaniline. In addition, certain merit of the compound which make it possible to use as a herbicide is discussed. The results are summarized as follows; 1. Recrystallizing technical BHC from methanol-water binary solvent system, r-isomer was enriched to 49.7% at 95% recovery of r-isomer. 2. By partitioning technical BHC in 85% of methanolic solution into chloroform, r-isomer was fortified to 89.6% at 90.5% recovery of r-isomer. 3. Yield of 1,2,4-trichlorobenzene from technical BHC was greatly dependent upon concentration of alkalies and to less degree on the alkalies. 4. Surfactants, in particular cationic a quartenary ammonium salt, increased yield of 1,2,4-trichlorobenzene from technical BHC by alkaline hydrolysis. 5. Conversion of 1,2,4-trichlorobenzene to 2,4,5-trichloronitrobenzene was effected almost quantitatively utilizing $HNO_3-H_2SO_4$ nitrating agent at low temperature. 6. Yield of 91.4% was observed for the synthesis of 2,4,5-trichloroaniline by reducing 2,4,5-trichloronitrobenzene in the presence of iron turning and hydrochloric acid. 7. Overall yield based on BHC of 3-(2,4,5-trichlorophenyl)-1- methyl urea was 60.8%. 8. Inhibition effects, both germination and growth, 3-(2,4,5-trichlorophenyl)-1-methyl urea on several crops were found comparable to or more potent than those of $linuron{\circledR}\;and\;diuron{\circledR}$. In addition, it was also noted that susceptibility to the prepared compound depended upon the crops as well as specific part (shoots, roots) of the plant exposed to the chemicals.

• Applied Biological Chemistry
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• v.22 no.3
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• pp.135-141
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• 1979

These experiments were conducted to investigate the conditions of the acid protease production by Rhizopus oryzae and the characteristics of crude enzyme. The results obtained were as follows: 1. The optimum culture time and the optimum amount of added water to the wheat bran medium were about 48 hrs and $80{\sim}120%$, respectively. 2. The addition of $(NH_4)_6Mo_7O_{24},\;(NH_4)_2SO_4,\;NH_4NO_3$, casein, and albumin, respectively, as nitrogen sources to the wheat bran medium was effective. Of these, the optimum concentrations of addition of $(NH_4)_6Mo_7O_{24}$ and casein which were the most effective were 0.1% and 1.0%, respectively. 3. The addition of glucose, galactose, maltose, lactose, and soluble starch, respectively, as carbon sources to the wheat bran medium was effective. Of these, the optimum concentration of addition of glucose which was the most effective was 3.0%. 4. The addition of $KH_2PO_4$ as a phosphate salt to the wheat bran medium was effective. The optimum concentration of addition of $KH_2PO_4$ was 0.3%. 5. The optimum pH for the enzyme action was 2.4, the optimum temperature about $40^{\circ}C$, and the stable pH range $2.0{\sim}5.0$. The enzyme was stab1e below $40^{\circ}C$. 6. The enzyme activity increased rapidly for 10 minutes after addition, thereafter it increased slowly. 7. The enzyme activity increased rapidly to 2 ml of addition, but nearly did not increase at the amounts greater than 2ml.

• Applied Biological Chemistry
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• v.28 no.3
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• pp.202-208
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• 1985

The significant chemical constituents estimating the quality of green tea were compared and analyzed in the tea shoots of native Korean tea plants. The tea shoots of different varieties among native tea plants were plucked in Waun-ri, Yongjang-ri, others in eight tea-growing places, and Yabukita, for the comparison, which is excellent Japanese variety. The contents of Yongjang-ri tea shoots were 0.55% lower in total nitrogen, 41.44mg% lower in vitamin C and 0.56% higher in tannin than the average of the other eight places. The contents of ash, caffeine and water extract showed no difference between the tea shoots. Tea shoots of Waunri had similar compositions compared with those of Yabukita and other eight places in the chemical constituents. It is considered that the tea loaves in Yongjang-ri would be different variety comparing with other eight places in the view of characters and constituents. And it is thought that tea loaves in Waun-ri would be the large leaf variety of same genealogy because tea loaves in Waun-ri was different from the other eight places in characters, but was similar to in constituents.

• Applied Biological Chemistry
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• v.22 no.3
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• pp.160-165
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• 1979

This study was carried out to investigate effects of iron content on the quality of soy sauce, bean paste and red pepper paste, and to elucidate the origin of iron and change of the contents during production processes. For the first step, the iron contents in commercial soy sauce and changes of the contents during brewing process were determined. The results obtained were as follows. 1, Iron contents of raw materials were 108 ppm in soy bean, 133ppm in defatted soy bean, 79 ppm in wheat, 5 ppm in sodium chloride, 58 ppm in seed koji, 300-2000 ppm in spore of Aspergillus oryzae, 240 ppm in wheat gluten, 20 ppm in sodium carbonate (above figures were of dry weight basis), 6 ppm in hydrochloric acid, 18 ppm in caramel and 0.3ppm in brewing water respectively. 2, Iron contents in koji were 200-240 ppm (as dry weight basis) and increased, more or less, in progress of koji-making period. 3. Iron contents in the mashes during fermentation were 40 rpm after 1 month, 43-47 ppm after 3 months and 49-62ppm after 6 months. 4. In chemical soy sauce, the iron content was 159 ppm after hydrolysis of wheat gluten with hydrochloric acid, and 184 ppm after neutralization. 5. Higher iron contents were detected both in fermented and chemical soy sauce when the concentration of total nitrogen increased, but the levels were higher in chemical soy sauce than in fermented one at the same concentration of total nitrogen. 6. In the case of fermented soy sauce, the iron content in the filtrate was decreased by press-filtration, but no significant change was found between before and after heat-sterilization. 7. Iron contents in commercial soy sauce were varied with the producers, however, the average value was 62.7 ppm as calculated as 1.0 percent of total nitrogen. And the average level of iron in home-made soy sauce produced by conventional method was 37.68 ppm.

• Applied Biological Chemistry
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• v.7
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• pp.21-27
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• 1966

This experiment was performed to investigate the effect of the frequency of meals on the metatolism and the body composition of rats when equal amount of purified diet was ingested. Thirty approximately days old rats weighing 290 g and thirty-two about 40 days old rats weighing 180 g were employed for the period of 34 days. Rats fed ad libitum (10 to 15 meals per day) and two-meal per day were pair-fed and equal amount of diet was fed to each rat in pair. The experimental results obtained are summarized as follows: 1. Frequency of meal did not exert any effect on the body weight gain. However, rats fed two-meal per· day gained significantly (p <0.005) more fat and energy than ad libitum group. The rate of gain of protein in ad libitum group was higher than that of two-meal group. No difference was observed for the mineral deposition of rat body. 2. From the preperation of rat liver it was found that the activity of glucose-6-phosphate dehydrogenase was much higher for the rats fed two-meals per day than those fed ad libitum. Therefore, it is suggested that the metabolic pathway of carbohydrate for two-meal group has been shifted from glycolysis to Hexose Monophosphate Shunt and produced more NADPH which would be the essential cofactor of fatty acids synthesis. 3. The rate of excretion of urinary nitrogen for two-meal group was significantly (p<0.005) higher than that of ad libitum group. It is apparent that considerable amount of over-loaded amino acids by feeding two-big-meal daily· could not be used for the protein biosynthesis all at once and excreted following deamination through urine. The residual carbon chain could be served as a precursor of fatty acids synthesis. 4. The heat production rate of rats fed two-meal group was significantly (p<0.005) lower than that of ad libitum group. It seems possible that the activity of thyroid gland (and consequently BMR) can be depressed by the frequency of meal.

• Applied Biological Chemistry
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• v.5
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• pp.7-21
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• 1964

가잠(家蠶)(Bombyx mori)의 잠체(蠶體), 용체 및 견사선(絹絲腺)(후부(後部))에서 phenol법(法)으로 RNA를 추출(抽出)하여 RNA의 nucleotide 조성(組成)(mole ratio)을 살피는 한편, 견사선(絹絲腺)(후부(後部))에서 초원심법(超遠沈法)으로 r-RNA, s-RNA를 분리(分離)하여 이에 대(對)한 nucleotide조성(組成)을 조사(調査)하고 또 가잠견사선(家蠶絹絲腺)과 비교(比較)할 목적(目的)으로 거미 방적선(紡績腺)의 t-RNA를 분리(分離)하여 nucleotide성분(成分)을 측정(測定)하여 다음과 같은 결과(結果)를 얻었다. 1) 잠란(蠶卵)에 있어서 이것을 마수(磨粹), 탈지(脫脂) 후(後) lysozyme을 작용(作用)시키고 10% NaCl용액(溶液)으로 가열(加熱) 추출(抽出)하는 새방법(方法)을 고찰(考察)하여 RNA의 추출(抽出)이 극난(極難)한 잠란(蠶卵)에서 RNA를 분리(分離)하는데 성공(成功)하였다. 2) 가잠란(家蠶卵), 잠체(蠶體), 용체 및 견사선(絹絲腺)(후부(後部))의 t-RNA nucleotide 조성(組成)은 다음과 같다. 시료(試料) $\frac{G+C}{A+U}$ $\frac{G+U}{A+C}$ $\frac{Pu}{Py}$ 가잠란(家蠶卵)의 RNA 1.14 1.24 0.99 가잠체(家蠶體)의 RNA 1.40 1.36 0.80 용체의 RNA 1.40 1.33 1.35 후부견사선(後部絹絲腺)의 RNA 1.05 1.32 1.15 이로서 잠체(蠶體). 용체 및 견사선(絹絲腺)의 Pu/Py는 각각(各各) 차이(差異)가 있으나 G+U/A+C는 3자간(者間)에 1.3의 거이 동일(同一)한 수치(數値)를 보여주고 있다. G+C/A+U는 잠체(蠶體)와 용체에 있어서 동일(同一)하나 견사선(絹絲腺)의 그것과는 차이(差異)가 있다. 한편 잠란(蠶卵)에 있어서는 Pu/Py, G+C/A+U, G+U/A+C가 각각(各各) 잠체(蠶體), 용체 및 견사선(絹絲腺)에 있어서와 현저(顯著)한 차이(差異)를 보여주고 있다. G+C/A+U가 1.3이나 되는 RNA의 base ratio를 가진 생물(生物)에 관(關)해서는 아직 보고(報告)된 바 없고 다만 본논문(本論文)의 가잠(家蠶)에 관(關)한 RNA와 속편(續編)인 각종(各種) 패류(貝類) RNA의 nucleotide 조성(組成)에서 모두 1.3에 가까운 수치(數値)를 보여주고 있다. 3) 견사선(絹絲腺)(후부(後部)) t-RNA와 거미 방적선(紡績腺)의 t-RNA의 nucleotide molar ratio 및 견사선(絹絲腺)의 r-RNA, s-RNA nucleotide 조성(組成)은 다음과 같다. 재료(材料) $\frac{G+C}{A+U}$ $\frac{G+U}{A+C}$ $\frac{Pu}{Py}$ 가잠견사선(家蠶絹絲腺)(후부(後部)의 t-RNA 1.05 1.32 1.15의 r-RNA 1.12 1.30 1.20의 s-RNA 1.55 1.33 0.65 지주방적선(蜘蛛紡績腺)의 t-RNA 1.35 1.24 1.16 즉(卽) 가잠견사선(家蠶絹絲腺)(후부(後部))과 거미방적선(紡績腺)의 t-RNA nucleotide 조성(組成)은 Pu/Py가 1.15와 1.16으로서 거이 동일(同一)하지만 G+C/A+U, G+U/A+C에 차이(差異)가 있음을 보았다. 한편 가잠견사선(家蠶絹絲腺)(후부(後部)) r-RNA와 s-RNA의 Pu/Py와 G+C/A+U는 현저(顯著)한 차이(差異)가 있고, G+U/A+C에 있어서는 1.3으로서 거이 동일(同一)한 수치(數値)를 보여주고 있다. 4. 이상(以上)과 같이 잠체(蠶體)에 관(關)한 RNA의 nucleotide 조성(組成)은 소위(所謂) GC-type로서, 현재(現在)까지 문헌(文獻)에 보고(報告)된 각종(各種) 생물(生物)의 RNA의 base ratio에 관(關)하여 비교(比較) 검토(檢討)하였으며, RNA의 nucleotide ratio의 차이(差異)의 의의(意義)에 대(對)하여 고찰(考察)하였다.