• Journal of the Mineralogical Society of Korea
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• v.21 no.3
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• pp.227-237
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• 2008

Arsenic has recently become of the most serious environmental concerns, and the worldwide regulation of arsenic fur drinking water has been reinforced. Arsenic contaminated groundwater and soil have been frequently revealed as well, and arsenic contamination and its treatment and measures have been domestically raised as one of the most important environmental issues. Arsenic behavior in geo-environment is principally affected by oxides and clay minerals, and particularly iron (oxy)hydroxides have been well known to be most effective in controlling arsenic. Among a number of iron (oxy)hydroxides, for this reason, 2-line ferrihydrite was selected in this study to investigate its effect on arsenic behavior. Adsorption of 2-line ferrihydrite was characterized and compared between As(III) and As(V) which are known to be the most ubiquitous species among arsenic forms in natural environment. Two-line ferrihydrite synthesized in the lab as the adsorbent of arsenic had $10\sim200$ nm for diameter, $247m^{2}/g$ for specific surface area, and 8.2 for pH of zero charge, and those representative properties of 2-line ferrihydrite appeared to be greatly suitable to be used as adsorbent of arsenic. The experimental results on equilibrium adsorption indicate that As(III) showed much stronger adsorption affinity onto 2-line ferrihydrite than As(V). In addition, the maximum adsorptions of As(III) and As(V) were observed at pH 7.0 and 2.0, respectively. In particular, the adsorption of As(III) did not show any difference between pH conditions, except for pH 12.2. On the contrary, the As(V) adsorption was remarkably decreased with increase in pH. The results obtained from the detailed experiments investigating pH effect on arsenic adsorption show that As(III) adsorption increased up to pH 8.0 and dramatically decreased above pH 9.2. In case of As(V), its adsorption steadily decreased with increase in pH. The reason the adsorption characteristics became totally different depending on arsenic species is attributed to the fact that chemical speciation of arsenic and surface charge of 2-line ferrihydrite are significantly affected by pH, and it is speculated that those composite phenomena cause the difference in adsorption between As(III) and As(V). From the view point of adsorption kinetics, adsorption of arsenic species onto 2-line ferrihydrite was investigated to be mostly completed within the duration of 2 hours. Among the kinetic models proposed so for, power function and elovich model were evaluated to be the most suitable ones which can simulate adsorption kinetics of two kinds of arsenic species onto 2-line ferrihydrite.

• Microbiology and Biotechnology Letters
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• v.8 no.3
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• pp.181-191
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• 1980

For the purpose of studies on the citric acid production, some experiments were carried out with isolated strains. The results obtained were as follows. 1) The optimal culture media of the strain M-80 in surface culture contained 140g of sucrose, 3.0g of (N $H_4$)$_2$S $O_4$, 1.5g of K $H_2$P $O_4$, 0.2g of MgS $O_4$.7$H_2O$, 3.0mg of F $e^{++}$, 1.0mg of Z $n^{++}$, 0.5N HCI to a pH of 5.0 and distilled water to 1.0 liter; and that of the strain M-315 in surface culture contained 140g of sucrose, 2.0g of N $H_4$N $O_3$, 1.0g of K $H_2$P $O_4$, 0.25g of MgS $O_4$. 7$H_2O$, 2.0mg of F $e^{++}$, 2.0mg of Z $n^{++}$, 0.05mg of C $u^{++}$, 0.5N HCI to a pH of 4.5 and distilled water to 1.0 liter. While that of the strain M-315 in submerged culture contained 140g of sucrose, 2.5g of N $H_4$N $O_3$, 1.5g of K $H_2$P $O_4$, 0.3g of MgS $O_4$. 7$H_2O$, 3.0mg of F $e^{++}$, 0.1mg of C $u^{++}$, 0.5N HCI to a pH of 4.5 and distilled water to 1.0 liter. The optimal temperature and size of inoculum were mostly 28-3$0^{\circ}C$, 10$^{7}$ -10$^{8}$ spores/50ml, respectively. 2) Through the course of citric acid production, the growth of strains had nearly been completed, pH value was rapidly decreased below 2.0 and the content of sugar was also reduced, while the accumulation of citric acid in media was remarkably begun in about 3-4 days. The yields of citric acid generally reached the maximum level in 8-10 days in surface or submerged fermentation process. 3) Methanol was effective citric acid production when they were added to fermentation media. In the case of surface culture, by addition of 2％ (strain M-80), 3％ (strain M-315), the yields of citric acid was increased 6.5％, 20.6%, respectively and 5.0% yield was increased by addition of 3% methanol in submerged culture media of the strain M-315. 4) Chromatography analysis of culture broth after fermentation under optimal culture conditions detected that the majority of acid in media was citric acid. 72.1mg/ml, 98.1mg/ml, of citric acid were determined in surface culture media by strains of M-80, M-315, and 59.8 mg/ml of citric acid was contained in the submerged culture media by the strain M-315. strain M-315.

• Tuberculosis and Respiratory Diseases
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• v.53 no.5
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• pp.497-509
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• 2002

Background : The mechanisms through which cellular activation results in intracellular mycobacterial killing is only partially understood. However, in vitro studies of human immunity to Mycobacterium tuberculosis have been largely modeled on the work reported by Crowle, which is complicated by several factors. The whole blood culture is simple and allows the simultaneous analysis of the relationship between bacterial killing and the effect of effector cells and humoral factors. In this study, we attempted to determine the extent to which M. tuberculosis is killed in a human whole blood culture and to explore the role of the host and microbial factor in this process. Methods : The PPD positive subject were compared to the umbilical cord blood and patients with tuberculosis, diabetes and lung cancer. The culture is performed using heparinized whole blood diluted with a culture medium and infected with a low number of M. avium or M. tuberculosis $H_{37}Ra$ for 4 days by rotating the culture in a $37^{\circ}C$, 5% $CO_2$ incubator. In some experiments, methlprednisolone- or pentoxifyline were used to inhibit the immune response. To assess the role of the T-cell subsets, CD4+, CD8+ T-cells or both were removed from the blood using magnetic beads. The ${\Delta}$ log killing ratio was defined using a CFU assay as the difference in the log number of viable organisms in the completed culture compared to the inoculum. Results : 1. A trend was noted toward the improved killing of mycobacteria in PPD+ subjects comparing to the umbilical cord blood but there was no specific difference in the patients with tuberculosis, diabetes and lung cancer. 2. Methylprednisolone and pentoxifyline adversely affected the killing in the PPD+ subjects umbilical cord blood and patients with tuberculosis. 3. The deletion of CD4+ or CD8+ T-lymphocytes adversely affected the killing of M. avium and M. tuberculosis $H_{37}Ra$ by PPD+ subjects. Deletion of both cell types had an additive effect, particularly in M. tuberculosis $H_{37}Ra$. 4. A significantly improved mycobacterial killing was noted after chemotherapy in patients with tuberculosis and the ${\Delta}$ logKR continuously decreased in a 3 and 4 days of whole blood culture. Conclusion : The in vitro bactericidal assay by human whole blood culture model was settled using a CFU assay. However, the host immunity to M. tuberculosis was not apparent in the human whole blood culture bactericidal assay, and patients with tuberculosis showed markedly improved bacterial killing after anti-tuberculous chemotherapy compared to before. The simplicity of a whole blood culture facilitates its inclusion in a clinical trial and it may have a potential role as a surrogate marker in a TB vaccine trial.

• Journal of Nutrition and Health
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• v.6 no.1
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• pp.1-9
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• 1973

I. Subject of the Study: Studies on the economical nutrition supplement of cereal foods for the improvement in our notional eating habits. II. Purpose and Importance of the Study: 1. Our nation is confronted with the situation that the rice, a principal food, short of some essential amino acids, lysine and threonine, leads to imbalanced meals insufficient in the nutrient of protein, to bring many difficulties in the elevation of our national physique. 2. The shortage of even the rice imperfect in the nutrient of protein makes the import of lots of foreign rice inevitable. It is considered that the protein supplement and decrease in the consumption amount, of rice, is a serious key to the solution of our food difficulty, and then a way of the proetin supplement of rice through the addition of essential amino acid is to be rarely applied in the view of the our present finance and situation. 3. In the present experiment, therefore, it aims to the suggestion of an aspect of the improvement in our national eating habits guiding in the nutrition elevation which our nation can afford economically through the development of first, a way of the protein supplement by the mixture of cereals producted plentifully in our country, and second, a way of the decrease in the consumption amount and the improvement in the nutrition of rice through the substitution of the other cereals for rice. III. Contents of Scope of the Study: 1. Objects of the study: Objects of the study are the following three items; a) The nutrition supplement of rice through the mixture of cereals. Our nation makes mainly rice as a principal food, but practically many kinds of cereal are produced in our country. They contain different levels and qualities of each nutrient and they are different from one another in the kinds of essential amino acid consisting protein. For that reason, the mutual complement efficeincy of insufficient nutrients is observed through the mixture of cereals. b) The nutrition supplement of rice through the addition of superior protein sources to rice, a principal food. The development of rice as superior foods in the sense of nutrition is conducted through the risement in protein quality by the addition of protein sources in good quality, for example, fish flour (anchovy flour), egg powder, milk powder, and so on, and through the supplement of vitamins and minerals. c) The decrease in the consumption amount of rice through the substitution of the other cereals for rice, as a principal food. The compensation for the short amount of rice is made by the reduction in the consumption of rice through the discovery of a way of substitution of the other cereals for rice, as a principal food and of the settlement of problems in nutrition and finance subsequent to this. 2. Contents of the study: a) An ideal mixture-ratio of cereals is established for rats by feeding mixed foods(rice-barely or rice-wheat) containing 5%, 15%, 25%, 35% and 45% level of either barely or wheat. b) The nutritive value is determined in the whole subsititution of other foods for rice, and then, a way of the complement of over and under nutrients is devised. c) The ideal combination is investigated for rats through feeding mixed foods of main food, rice and supplement foods of protein sources, soy bean, fish flour, egg powder and milk Powder. d) According to results from the above three experiments, the concise functional test for men and the examination of economical property are made. 3. Scope of the study: a) The observation of the effect of each diet on the growth rate for rats. The growth rate of rats was observed for 15 groups of mixed foods of a main food, rice, and wheat flour, barley powder or soy bean powder, respectively, and 12 groups of wheat flour diets supplemented with $1{\sim}3%$ milk powder, and rice or wheat flour diets supplemented with 5% of milk powder, egg powder, fish flour or soy bean powder, respectively. b) The determination of food consumption. The food consumption was determined at weekly intervals for 27 kinds of diet described in a) item. c) The determination of food efficiency rate. The food efficiency rate for each diet was determined by calculation from the gained body weight and the food consumption amount at the same intervals described in b) item. d) The determination of protein efficiency rate. The protein efficiency rate for each diet was determined by calculation form gained body weight and the protein amount of the food consumption amount at the same intervals described c) item. e) The determination of the body component. The hematocrite and hemoglobin levels in the blood, total nitrogen in the serum, blood sugar, and lipids and glycogen in the liver were determined. f) The observation of nitrogen balance. As a means of the observation of nitrogen balance, the total nitrogen in the urine was determined. g) The analysis of economical property. The economical property was analyzed as the gained body weight to the amount equivalent to one won through the conversion of the food consumption amount into money. h) The functional test for men. The concise functional test for men was made in order to establish if the best diet for experimental animals can be applied to men. IV. Results of the Study: The national food product plan, nationwide nutritive enlightment and the improvement activities in our country eating habits, especially, mixed and powder food problems are to be significantly referred, and the following results must be applied. a) In the mixed foods of cereals, the mixed food of the rice-barley containing $5{\sim}15%$ level of barley is best in terms of nutrition. b) The addition of superior protein sources, egg, Bilk, soy bean, or fish, respectively to either rice or wheat flour makes a great risement in the nutritive value. c) The animal protein is more effective in the elevation of nutritive value of cereals. d) Rice takes the most nutritive operation and has the highest preference, among rice, wheat flour and barley. e) Wheat flour is more economical than rice in evaluation of the gained body weight to the regular money, and the addition of fish or soy bean is more economical than that of any other supplement food. But the above results are true of the range of nutrition and economical property. f) The study on the nutrition composition and barley will lead to the improvement in our national eating habits as mixed food of the rice-barley containing $5{\sim}15%$ level of barley is more nutritive. g) This study on the nutrition only for the growing animal can not be considered as a perfect and entire evaluation. Consequently, the perfect data for our national nutrition can be obtained from the experiment similar to this for the much longer period examining, in details, the growth rate, change of physical strength, mental and bodily change, average life span, and resistance ability to infectious diseases.

• Journal of Music and Human Behavior
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• v.4 no.2
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• pp.66-83
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• 2007

The purpose of this study is to learn both effects of the vocal psychotherapy on the self-consciousness and the variety of the self-consciousness on the vocal psychotherapy in return. The research for this study was performed to three subjects who were students of E university, Seoul, ten times for sixty minutes. The subjects were all volunteers for the advertisement on a music-therapy program searching for them on the web site of E university. The vocal psychotherapy program consists of four steps and each of them consists of two to four short terms again. Both before and after the experiment, examinations on self-consciousness were done to recognize the change of the subjects' self-consciousness which would be caused by the vocal psychotherapy activity. After every short term, the subjects were asked to write reports to closely analyze the change of self-consciousness according to the terms and the variety of the subjects. The effect of the vocal psychotherapy activity on the changes of scores in the self-consciousness examination is the first thing to point out on this study. There appeared some personal varieties on the total scores of the examination and scores of some sub-categories. Especially, there were different scores on the private self-consciousness, the public self-consciousness, and the social anxiety between before and after performing the vocal psychotherapy program. Subject A, who had got the best score of all on the scope of the private self-consciousness, showed the steepest decrease on the very scope. On the contrary, the subject showed decrease of scores of the public self-consciousness and the social anxiety in the relatively little rate. Subject B, who had got the highest score of the three on the public self-consciousness, showed the steepest decrease on that of all scopes and showed no difference on the social anxiety scope. In the case of the last one, subject C, who had relatively low scores on the private and public self-consciousness than the others, the private self-consciousness score increased but the public self-consciousness and the social anxiety scores decreased. The changes of the scores of each questions were examined in order to see possible other changes that had not been exposed on the changes of the total and sub-categories scores. As a result of that, of all twenty-eight questions, there were changes about one to two points. Subject A showed the difference with thirteen questions, subject B with sixteen and subject C with nineteen questions. The rate of change of subject C was relatively small but more questions changed and the change of score was wider than the others. Considering all those results, It can be possibly said that the vocal psychotherapy affects the changes of the scores of sub-categories in self-consciousness examination. The next thing to point out on this study is the change of recognition that was exposed on the subjects' report after every short term of the program. As a result of the close analyzing, according to the short terms and variety of self-consciousness, recognizing the way express subjects themselves by voice and recognizing their own voices appeared to be different. How much they cared about others and why they did so were also different. According to the self reports, subject A cared much about her inner thought and emotion and tended to concentrate herself as a social object. There appeared some positive emotional experiments such as emotional abundance and art curiosities on her reports but at the same time some negative emotions such as state-trait anxiety and neuroticism also appeared. Subject B, who showed high scores on the private and public self-consciousness like subject A, had a similar tendency that concentrates on herself as a social object but she showed more social anxiety than subject A. Subject C got relatively lower points in self-consciousness examination, tended to care about herself, and had less negative emotions such as state-trait anxiety than other subjects. Also, with terms going on, she showed changes in the way of caring about her own voice and others. This study has some unique significances in helping people who have problems caused by self-estimation activated with self-consciousness, using voices closely related to one's own self, performing the vocal skills discipline to solve the technical problems. Also, this study has a potentiality that the vocal psychotherapy activity can be effectively used as a way affects the mental health and developing personality.

• Korean Journal of Soil Science and Fertilizer
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• v.8 no.1
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• pp.1-17
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• 1975

Laboratory experiments on the phosphorus adsorption by soil were conducted to evaluate the parameters for determination of phosphorus adsorption capacity of soil, which serve as a basis for establishing the amount of phosphorus required to improve newly reclaimed soil and volcanic ash soil. The calculated Langmuir adsorption maxima varied from 6.2-32.9, 74.7-90.4 and 720-915mg p/100g soil for cultivated soils, non-cultivated soils, and volcanic ash soils respectively. The phosphorus absorption coefficient ranged from 116-179, 161-259 and 1,098-1,205mg p/100g soil for cultivated soils, non-cultivated soils, and volcanic ash soils respectively. The ratio of the phosphorus absorption coefficient to Langmuir adsorption maximum was low in soils of high phosphorus adsorption capacity (1.3-1.5) and high in soils of low phosphorus adsorption capacity (2.2-18.7). Changes in the amount of phosphurus adsorption induced by liming and preaddition of phosphorus were hadly detected by the phosphorus absorption coefficient, which is measured using a test solution with a relatively high phosphorus concentration. The Langmuir adsorption maximum was a more sensitive index of the phosphorus adsorption capacity. The Langmuir adsorption maxima of the non-cultivated soils, which were treated with an amount of calcium hydroxide equivalent to the exchangeable Al and incubated ($25-30^{\circ}C$) for 40 days at field capacity, were lower than the original soils. The change in the adorption maximum on incubation following the liming of soils was insignificant for other soils. The secondary adsorption maximum of soils, which received phosphorus equivalent to the Langmuir adsorption maximum of the limed soils incubated ($25-30^{\circ}C$) for 50 days at held capacity, was 74.5, 5.6 and 23.8% of the primary adsorption maximum for volcanic ash soils, non-cultivated soils, and cultivated soils respectively. The amount of phosphorus adsorbed by soils increased quadratically with the concentration of phosphorus solution added to the soils. The amount of phosphorus adsorbed by 5-g soil samples from 100ml of 100- and 1,000mg p/l solution for the mineral soils and volcanic ash soils respectively was found to be close to the Langmuir adsorption maximum. The amount of the phosphorus adsorbed at these concentrations is defined as a saturation adsorption maximum and proposed as a new parameter for the phosphorus adsorption capacity of the soil. The evaluation of the phosphorus adsorption capacity by the saturation adsorption maximum is regarded as a more practical method in that it obviates the need for the various concentrations used for the determination of the Langmuir adsorption maximum.

• Journal of the Korean Society for Marine Environment & Energy
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• v.18 no.1
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• pp.1-8
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• 2015

To evaluate accuracy and precision of determination of total alkalinity ($Alk_T$) and carbon dioxide ($TCO_2$) derived from present study, experiment was applied with $CO_2$ CRM (Batch 132, Scripps Institution of Oceanography; $Alk_T=2229.24{\pm}0.39{\mu}mol/kg$, $TCO_2=2032.65{\pm}0.45{\mu}mol/kg$). As the result, average concentration of $Alk_T$ and $TCO_2$ was $2354.09{\mu}mol/kg$ (~5.6% difference with $CO_2$ CRM) and $2089.60{\mu}mol/kg$ (~2.3% difference with $CO_2$ CRM), respectively. For previous method (Gran Titration) by addition $NaHCO_3$ to deionized water($Alk_T$ $2023.33{\mu}mol/kg$), average concentration was $2193.39{\mu}mol/kg$ (sd=57.15, n=7). Whereas, average concentration was $2017.02{\mu}mol/kg$ (sd=10.98, n=7) for the present study. Recovery yield experiments of total alkalinity in deionized water and seawater were implemented by addition of $NaHCO_3$. The recovery yield of deionized water in the range 0 to $4952.39{\mu}mol/kg$ was 100.8% ($R^2$=0.999), and seawater in the range 0 to $2041.32{\mu}mol/kg$ was 102.3% ($R^2$=0.999). Comparison of $pCO_2$ sensor (PSI $CO_2-Pro^{TM}$) with present method showed very meaningful correlation coefficient ($R^2$=0.977) in the range of 427 to $705{\mu}atm$ and 9.16 to $15.24{\mu}mol/kg$ throught elapsed time for two weeks. Field experiment of diurnal variation of total carbon dioxide was accomplished at Sachon harbor in the coastal waters of East Sea of Korea. Concentration of $Alk_T$ and $TCO_2$ was increased during night, and decreased during daylight hours. The results showed mirror type between $TCO_2$ and dissolved oxygen, which was attributable to photosynthesis and respiration of phytoplankton. Also, open ocean field study was performed to obtain vertical profile of $Alk_T$ and $TCO_2$ in C-C zone (Clarion-Clipperton Fracture Zone), Northeastern Pacific. Average concentrations of $Alk_T$ in the surface mixed layer (0~60 m) and deeper layer below 200 m were $2422.38{\mu}mol/kg$ (sd=78.73, n=20) and $2465.87{\mu}mol/kg$ (sd=57.68, n=103), respectively. And average concentrations of $TCO_2$ were $2134.47{\mu}mol/kg$ (sd=65.4, n=20) and $2431.87{\mu}mol/kg$ (sd=65.02, n=103) in the same depth ranges such as $Alk_T$. Vertical distributions of $Alk_T$ and $TCO_2$ concentrations tended to increase with depth, and analyzed concentrations showed slightly higher than those of previous studies in this area.

• Applied Biological Chemistry
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• v.15 no.3
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• pp.213-219
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• 1972

In order to utilize sweet potatoes for the material of Takju, brewing experiments with raw sweet potatoes, sweet potato chips powder and its koji were conducted; and various tests were carried out on effect of the treatments of acid, alkali, polyphenol oxidase inhibitor, oxidizing and reducing agents upon the prevention against coloring of sweet potato chips by steaming, and on peeling effect of sweet potatoes by the alkali and heat treatments. The results obtained were as follows. 1) In the case of brewing with raw sweet potatose, each plot showed low acid and ethanol content, and its finished Takju had an undersirable color and odor. The plots which were mashed after peeling showed higher ethanol contents than the plots mashed without peeling. 2) In the case of brewing with sweet potato chips powder, each plot contained considerably more amount of ethanol than the plots brewed with raw sweet potatoes, white it contained less amount of acid. The ethanol contents of the plots using wheat bran koji were $10.5{\sim}11.4$ per cent 4 days after mashing, and were higher than those of the plots using malts powder. Their finished Takju was inferior in quality because of the lack of acid and being darkened gradually in process of time. 3) The kojies which were made of sweet potato chips powder with Neurospora sitophila or Aspergillus oryzae had good appearance, but the Takju mashes brewed with these contained remarkably less amount of ethanol. 4) Effect of the treatments of acid, alkali, polyphenol oxidase inhibitor and organic solvents such as ether and ethanol upon the prevention against coloring of sweet potato chips was not recognized. Alum and burnt alum were effective a little on the decolorization, and among the oxidizing and reducing agents tested, potassium permanganate was most effective. 5) Darkening of sweet potato chips powder in course of heating after mixing with water was not affected by pectin and amino acids, but by tannin. 6) Sweet potatoes were not peeled easily by friction after soaking in the boiling solution of 3 per cent alkali for 6 minutes and peeled in boiling water for 12 minutes. From the viewpoint of the results above mentioned, it seems to be necessary to study further on the isolation of microorganisms which are able to decompose the coloring substances and yeasts which are adequate for the fermentation of sweet potatoes in order to utilize sweet potatoes for Takju brewing, because brewing with raw sweet potatoes, sweet potato chips powder and its koji was unsuccessful, and effect of the various treatments on the decolorization of sweet potatoes was not recognized.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.25 no.2
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• pp.79-92
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• 1992

This study was carried out to develop new techniques useful for cryopreservation, thawing and artificial insemination, and ultrastructural changes of cryopreserved spermatozoa in rainbow trout(Oncorhynchus mykiss) . Two extenders, such as Tyrode solution and Whittingham's $T_6$ solution, were used to preserve rainbow trout sperm in refrigerator $(-20,\;-40\;and\;-70^{\circ}C)$ or liquid nitrogen $%(-196^{\circ})$. Hand-stripped semen was diluted to 1:16 with two extenders, an then the semen were frozen after mixing semen and each extender containing 1M or 1.5M DMSO solution to 1:1. After 60 days cryopreserved semen was thawed in a $13^{\circ}$ water bath, and subsequently centrifugated. After centrifugation at 1,000 rpm for 5 min thawed semen was washed with extenders, and then fertilized with fresh eggs. The results obtained in these experiments were summarized as follows: After cryopreservation, over 75% of spermatozoa were appeared motile and the survival rate was high. Following cryopreservation by the addition of cryoprotectant such as DMSO, methanol and glycerol, the fertilization rate of the thawed spermatozoa appeared over $99\%$ compared with the control having $99\%$ of fertilization rate. There was no difference between the control and experimental groups such as $(-20^{\circ}C\;-40^{\circ}C\;and\;-70^{\circ}C)$ and $-196^{\circ}$ in fertilization rate. Following cryopreservation at $-196^{\circ}$ by the addition of 1M DMSO of cryoprotectant, each fertilization rate following 24 hours and hatching rate following 24 days showed $96\%$ and $8\%$ by the addition of BSA, but showed $98\%\;and\;10%$ by no addition of BSA. Following 2 months of cryopreservation by the addition of 1M DMSO of cryoprotectant, there were $10%$ of hatching rate at $-196^{\circ}\;and\;10\%\;and\;35\%,\;respectively,\;at\;-40^{\circ}C\;and\;-70^{\circ}C$. Following 2 months of cryopreservation by the addition of 1M methanol of cryoprotectant, there were $22\%$ of fertilization rate at $-20^{\circ}C,\;and\;28\%,\;at\;-70^{\circ}C$ Following 2 months of cryopreservation by the addition of 1M glycerol of cryoprotectant, there were $22\%$ of fertilization rate at $-20^{\circ}C$, and $33\%,\;at\;-70^{\circ}C$. pollowing 2 months of cryopreservation by the addition of 1.5M DMSO of cryoprotectant, there were $27\%$ of fertilization rate at $-20^{\circ}C,\;an\;36\%\;and \;35\%,\;respectively,\;at\;-40^{\circ}C\;and\;-70^{\circ}C$. Following 2 months of cryopreservation by the addition of 1.5M glycerol of cryoprotectant, there were $34\% \;of\;fertilization\;rate\;at\;-20^{\circ}C, \;and\;31\%\;and\;31\%,\;respectively,\;at \;-40^{\circ}C\;and\;-70^{\circ}$. Following 2 months of cryopreservation by the addition of 1.5M methanol of cryoprotectant, there were $28\%$ of fertilization rate at $-20^{\circ}C,\;and\;29\%\;and\;28\%,\;respectively,\;at\;-40^{\circ}C\;and\;-70^{\circ}C.$ From 10 days and 15 days following fertilization at $13^{\circ}C\;and\;10^{\circ}C$, respectively, the mortality rate of fertilized ova was markedly increased. The middle piece of spermatozoa had two set of central doublets, nine set of outer coarse fibres, and mitochondrial sheath. Spermatozoa went through morphological changes during storage, e.g. winding of flagella, detachment of the nuclear envelope and the plasma membrane from the nucleus of the sperm head. There were $1\%$ abnormal spermatozoa in fresh sperm and about $15\%$ during storage.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.18 no.3
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• pp.195-205
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• 1985

As a part of investigation to use the Anatrctic krill, Euphausia superba, more effectively as a food source, processing conditions, utilizations and storage stability of krill paste (intermediate product of krill) were examined and also chemical compositions of krill paste were analyzed. Frozen raw krill was chopped, agitated with $25\%$ of water to the minced krill and then centrifuged to separate the liquid fraction from the residue. This liquid fraction was heated at $98^{\circ}C$ for 20 min. to coagulate the proteins of krill, and it was filtered to separate the protein fraction. Krill paste was prepared with grinding the protein fraction, adding $0.2\%$ of polyphosphate and $0.3\%$ of sodium erythorbate to the krill paste for enhancing of functional properties and quality stability. The krill paste was packed in a carton box, and then stored at $-30^{\circ}C$. Chemical compositions of krill paste were as follows : moisture $78\%$, crude protein $12.9\%$, crude lipid $5.9\%$, and the contents of hazardous elements of krill paste as Hg 0.001 ppm, Cd 1.15 ppm, Zn 9.1 ppm, Pb 0.63 ppm and Cu 11.38ppm were safe for food. The amino acid compositions of krill paste showed relatively high amount of taurine, glutamic acid, aspartic acid, leucine, lysine and arginine, which occupied $55\%$ of total amino acid and also taurine, lysine, glycine, arginine and proline were occupied $65\%$ of total free amino acid. Fatty acid compositions of krill paste consist of $32.4\%$ of saturated fatty acid, $29.6\%$ of monoenoic acid and $38.0\%$ of polyenoic acid, and major fatty acids of product were eicosapentaenoic acid ($17.8\%$), oleic acid ($16.9\%$), palmitic acid ($15.3\%$), myristic acid ($8.7\%$) and docosahexaenoic acid ($8.4\%$). In case of procssing of fish sausage as one of experiment for krill paste use, Alaska pollack fish meat paste could be substituted with the krill paste up to $30\%$ without any significant defect in taste and texture of fish sausage, and the color of fish sausage could be maintained by the color of krill paste. Judging from the results of chemical and microbial experiments during frozen storage, the quality of krill paste could be preserved in good condition for 100 days at $-39^{\circ}C$.