• The Korean Journal of Physiology
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• v.2 no.2
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• pp.101-135
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• 1968

As physical fitness measured was muscle strength (hand grips, leg extention, back lift, and arm pull and thrust), skinfold thickness (5 different sites), circulatory function (resting heart rate and blood pressure), speed (kinesiological analysis during 100m sprint, record, maximal and final speed), motor function (50 meter dash, ball throwing, standing broad jump, and pull-ups), maximal aerobic power (maximum oxygen intake by field running method), muscle power (leg and arm by inertia ergometer), and general endurance (maximum endurance running time on the treadmill at the speed of 5 MPH and grade of 15.5%) of 1131 Korean children (boys 572, girls 559) aged of 6 to 17 years, who were randomly sampled from 24 primary, middle and high schools at the two districts of Seoul and KyungKi. The results are summarized as follows: 1) The status (height and weight) of the children was almost same as that of the previously reported Korean and Japanese children of same ages. 2) Muscle strength was a gained linearly with geting age in the boys and girls but there was a little improvement in girls aged of 13 years or more. 3) The mean skin fold thickness was increased linearly with geting ages in both sexes, but the girls from 12 to 17 years of age were increased rapidly, and maximum value was 17mm, while boys was 7.0 mm. 4) In the circulatory function, the resting heart rate was decreased, but the blood pressure was increased with ages in both sexes within the normal limits. 5) The maximum and final speed during 100 meter sprint increases with age in boys but girls who are 12 years old or older, were not improved any mere. The patterns of running were same in both sexes, and maximum speed reached at about 30 meters from starting line. 6) The motor function was increased with age in both sexes, but there was no improvement in 12 years of age or older girls. More over records of all functions except standing broad jump was less than those of Japanese in the same age, respectively. 7) The maximum oxygen intake (MOI) was increased considerably with ages and maximum values were 2.93 L/min (boys) and 2.09 L/min (girls) at the age of 17years. This result was almost same as that of the Japanese and Easter Island population, but the value was lower than that of Europe. The average of the maximum oxygen intake per kg body weight per minute from 9 to 17 years of age were around 53 ml in the boys and 42 ml in the girls. 8) Muscle power was increased linearly with ages in boys while there was relatively a little increment in girls. The maximum values of leg muscle in boys and girls at the 17 years of age were 0.168 and 0.088 horse power, respectively. 9) The maximum endurance running time was increased considerably from the age of 9 in boys, while there was no improvement in girls. The maximum values were 6.0 min and 1.8 min, respectively.

• Journal of Environmental Impact Assessment
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• v.28 no.6
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• pp.604-615
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• 2019

In this study, we produce a new type of the algae soil conditioner(ASC) using discarded algae biomass through a composting process and evaluate its nutritional characteristics. As the main ingredient, the ASCs used algae biomass collected through the coagulation-floating method and made by adding a variety of additional supporting materials (sawdust, pearlite, oilcake etc.). ASCs were divided into 0% in blank, 11.7% in ASC1, 21.6% in ASC2, 37.6% in ASC3, 59.5% in ASC4, and composted during 127 days. ASCs showed a sharp increase in temperature by aerobic microbial reaction, and 6~7 high and low temperature peaks were observed. As a result of physicochemical analysis, mineralization proceeded according to decomposing the organic matter and there was a marked increase not only in macronutrients (TN, P₂O₅, K₂O), but also in secondary macronutrients (CaO, MgO). The microbial community change was found in stage 1 (bacteria, filamentous fungi) → stage 2 (actinomycetes, bacteria) → stage 3 (Bacillus sp.), depending on the maturation process. It was estimated that microbial transition was closely related to temperature change and nutritional behavior. The quality of soil conditioner can be determined according to the maturity of compost process, and it was determined that effective microbial activity could be induced by controlling algae biomass below 59.5% in this study. In conclusion, we found out the possibility of manufacturing and utilizing soil conditioner recycled algae biomass and if further technological development is made on the basis it can be used as an effective soil conditioner.

• Journal of Korean Society of Environmental Engineers
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• v.33 no.1
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• pp.25-31
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• 2011

In this study, model-based $NH_4-N$ predictive control algorithm by using influent pattern was developed and evaluated for effective control application in $A^2/O$ process. A pilot-scale $A^2/O$process at S wastewater treatment plant in B city was selected. The behaviors of organic, nitrogen and phosphorous in the biological reactors were described by using the modified ASM3+Bio-P model. A one-dimensional double exponential function model was selected for modeling of the secondary settlers. The effluent $NH_4-N$ concentration on the next day was predicted according to model-based simulation by using influent pattern. After the objective effluent quality and simulation result were compared, the optimal operational condition which able to meet the objective effluent quality was deduced through repetitive simulation. Next the effluent $NH_4-N$ control schedule was generated by using the optimal operational condition and this control schedule on the next day was applied in pilot-scale $A^2/O$ process. DO concentration in aerobic reactor in predictive control algorithm was selected as the manipulated variable. Without control case and with control case were compared to confirm the control applicability and the study of the applied $NH_4-N$control schedule in summer and winter was performed to confirm the seasonal effect. In this result, the effluent $NH_4-N$concentration without control case was exceeded the objective effluent quality. However the effluent $NH_4-N$ concentration with control case was not exceeded the objective effluent quality both summer and winter season. As compared in case of without predictive control algorithm, in case of application of predictive control algorithm, the RPM of air blower was increased about 9.1%, however the effluent $NH_4-N$ concentration was decreased about 45.2%. Therefore it was concluded that the developed predictive control algorithm to the effluent $NH_4-N$ in this study was properly applied in a full-scale wastewater treatment process and was more efficient in aspect to stable effluent.

• Journal of Korean Society of Environmental Engineers
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• v.33 no.11
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• pp.812-820
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• 2011

This study was conducted to characterize $CO_2$ biomineralization on several minerals (i.e., CaO, MgO, $SiO_2$) by bottle test in an aqueous solution and solidified sludge using different aerobic bacterial strains like Bacillus megaterium and Bacillus pasteurii by batch test. These bacteria promote the formation of microenvironments that facilitate the precipitation of mineral phases that were unsaturated in the bulk solution. For one type of mineral solely amended, the $CO_2$ was reduced at the highest of 4.0 mmol for MgO while it was not that much lower for CaO and $SiO_2$ showing 1.1 and 0.3 mmol $CO_2$2, respectively. For two types of minerals simultaneously amended, the $CO_2$ was reduced at the greater extent for both Ca + Mg and Mg + Si showing 2.7 and 2.3 mmol, respectively whereas it was less for Ca + Si at 1.8 mmol. For solidified sludge, the $CO_2$ reduction rate changed depending on the volume of solidified sludge placed in the medium and the input $CO_2$ concentration.. The reduction rate of $CO_2$ was increased with increasing the volume of solidified sludge. Results of XRD analysis indicate that $CaCO_3$ (Calcite) was dominantly formed among others (e.g., Aragonite, Dolomite). SEM analysis showed that the sample with Bacillus pasteurii, could more form minerals rather than control. As demonstrated in this study, $CO_2$ would be effectively sequestered in biomineralization process.

• Korean Journal of Environmental Agriculture
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• v.16 no.4
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• pp.295-303
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• 1997

To investigate the transformation characteristics of nitrogen and carbon from cow manure compost amended in soil under different moisture conditions, dynamics of nitrogen and carbon were determined periodically for 15 weeks of aerobic incubation at room temperature during July${\sim}$November, 1996. Cow manure compost matured with mixing saw dust was amended with the 4 ratios (0, 2, 4, 6%(wt/wt)) in Ap horizon soil, which collected from green house in Yesan, Chungnam. Moisture was controlled with 0.2, 0.3, 0.4, and 0.5 of mass water conte nt (${\theta}$m) to air dried soil, and water loss was compensated at every sampling. During incubation, soil pH was decreased continuously, that was caused by hydrogen generated from nitrification of ammonium nitrogen. And pH became higher with inclining cow manure compost amendment and water treatment, that meaned the increase of mineralization of organic-N to $NH_4\;^+-N$. Total nitrogen was reduced with increasing water content, but total carbon showed the contrast tendency with that of nitrogen. Therefore, C/N ratio slightly decreased in the low water condition (${\theta}$m 0.2) during incubation, but increased continuously in high water condition over ${\theta}$m 0.4. As a result, it was assumed that soil fertility is able to be reduced in the high water content over available water content. Nitrate transformation rate increased lasting in the low water content less than ${\theta}$m 0.3. Itdropped significantly in the first $2{\sim}3$ weeks of incubation over ${\theta}$m 0.4. In particular, nitrate was not detected in ${\theta}$m 0.5 of water content after the first $2{\sim}3$ weeks. In contrast, ammonium transformation was inclined with increasing water treatment. Nitrogen mineralization rate, which calculated with percentage ratio of (the sum of ex.$NH_4\;^+-N$ and $NO_3\;^--N$)/total nitrogen, was continuously increased in the low water content of ${\theta}$m 0.2 and 0.3. But it saw the different patterns in high water content over ${\theta}$m 0.4 that was drastically declined in the initial stage and then gradually inclined . From the above results, nitrogen transformation patterns differentiated decisively in water content between ${\theta}$m 0.3 and 0.4 in soil. Thus, it is very important for the maintain of suitable soil water content to enhance fertility of soil amended with manure compost. However, excess treatment of manure compost might enhance the possibility of contamination of small watershed and ground water around agricultural area.

• 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 %.

• Korean Journal of Microbiology
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• v.32 no.2
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• pp.155-162
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• 1994

Cells of Acinetobacter sp. strain JC1 DSM 3803, an aerobic monoxide-oxidizing bacterium, growing on glucose exhibited high catalase activity at the mid-exponential growth phase. The enzyme activity decreased gradually after then until the early stationary phase, increased again at the mid-stationary phase, and then decreased again thereafter. Cells growing on glucose was found to contain three kinds of catalses. Cat1, Cat2 and Cat3. The activities of Cat1 and Cat3 did change significantly during growth, but that of Cat2 exhibited significant variation. Cat3 was found to present only in cells growing on glucose, but not in cells growing on carbon monoxide of methanol. The activities of call and Cat3 in cell-free extracts were stable upon treatment with ethanol and chloroform, but decreased to some extent when the enzymewere treated with 2mM $H_2O_2$ and/or 3-amino-1,2,4-triazole (AT). Cat2 was found to be extremely sensitive to the ethanol-chloroform and $H_2O_2$ treatments, but was insensitive to the AT treatment. Cat1 exhibited enzyme activity after incubation for 1 min at 80$^{\circ}C$. Cat2 and Cat3 did not show enzyme activity after incubation for 1 min at 60$^{\circ}C$ and 70$^{\circ}C$, respectively. Cat2 was found to have peroxidase activity. Cat3 was purified to homogenity in seven steps. The molecular weight of the native enzyme was estimated to be 150,000. Sodium dodecyl sulfate-gel electrophoresis revealed two identical subunits of molecular weight 65,000. The enzyme was found to show two $K_m$ values of 39 mM and 58mM. The optimal pH for the enzyme activity was 7.0, but the activities at pH 6.0, 8.0, and 9.0, were found to be comparable to that at the optimal pH. The optimal temperature for the enzyme activity was found to be 40$^{\circ}C$. The enzyme also exhibited strong activity at 20$^{\circ}C$, 30$^{\circ}C$, and 50$^{\circ}C$. The purified enzyme was not affected by the ethanol-chloroform treatment. The enzyme, howerver, showed less than 10% of the original activity when it was treated with 12 mN AT, 0.1 mM $NaN_3$ of 1mM KCN.

• Korean Journal of Microbiology
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• v.53 no.2
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• pp.83-96
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• 2017

A constructed sea stream in Yeongdo, Busan, Republic of Korea is mostly static due to the lifted stream bed and tidal characters, and receives domestic wastewater nearby, causing a consistent odor production and water quality degradation. Bioaugmentation of a microbial consortium was proposed as an effective and economical restoration technology to restore the polluted stream. The microbial consortium activated on site was augmented on a periodic basis (7~10 days) into the most polluted site (Site 2) which was chosen considering the pollution level and tidal movement. Physicochemical parameters of water qualities were monitored including pH, temperature, DO, ORP, SS, COD, T-N, and T-P. COD and microbial community analyses of the sediments were also performed. A significant reduction in SS, COD, T-N, and COD (sediment) at Site 2 occurred showing their removal rates 51%, 58% and 27% and 35%, respectively, in 13 months while T-P increased by 47%. In most of the test sites, population densities of sulfate reducing bacterial (SRB) groups (Desulfobacteraceae_uc_s, Desulfobacterales_uc_s, Desulfuromonadaceae_uc_s, Desulfuromonas_g1_uc, and Desulfobacter postgatei) and Anaerolinaeles was observed to generally decrease after the bioaugmentation while those of Gamma-proteobacteria (NOR5-6B_s and NOR5-6A_s), Bacteroidales_uc_s, and Flavobacteriales_uc_s appeared to generally increase. Aerobic microbial communities (Flavobacteriaceae_uc_s) were dominant in St. 4 that showed the highest level of DO and least level of COD. These microbial communities could be used as an indicator organism to monitor the restoration process. The alpha diversity indices (OTUs, Chao1, and Shannon) of microbial communities generally decreased after the augmentation. Fast uniFrac analysis of all the samples of different sites and dates showed that there was a similarity in the microbial community structures regardless of samples as the augmentation advanced in comparison with before- and early bioaugmentation event, indicating occurrence of changing of the indigenous microbial community structures. It was concluded that the bioaugmentation could improve the polluted water quality and simultaneously change the microbial community structures via their niche changes. This in situ remediation technology will contribute to an eco-friendly and economically cleaning up of polluted streams of brine water and freshwater.

• Journal of Life Science
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• v.17 no.12
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• pp.1660-1668
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• 2007

The non-ionic surfactant (NIS) Tween 80 was evaluated for its ability to influence invitro cumulative gas production, dry matter digestibility, cellulolytic enzyme activities, anaerobic microbial growth rates, and adhesion to substrates by mixed rumen microorganisms on rice straw, alfalfa hay, cellulose filter paper and tall fescue hay. The addition of NIS Tween 80 at a level of 0.05% increased significantly (P<0.05) in vitro DM digestibility, cumulative gas production, microbial growth rate and cellulolytic enzyme activity from all of substrates used in this study. In vitro cumulative gas production from the NIS-treated substrates; rice straw, alfalfa hay, filter paper and tall fescue hay was significantly (P<0.05) improved by 274.8, 235.2, 231.1 and 719.5% compared with the control, when substrates were incubated for 48 hr in vitro. The addition of 0.05% NIS Tween 80 to cultures growing on alfalfa hay resulted in a significant increase in CMCase (38.1%), xylanase (121.4%), Avicelase (not changed) and amylase (38.2%) activities after 36 h incubation. These results indicated that the addition of 0.05% Tween 80 could greatly stimulate the release of some kinds of cellulolytic enzymes without decreasing cell growth rate in contrast to trends reported with aerobic microorganism. Our SEM observation showed that NIS Tween. 80 did not influence the microbial adhesion to substrates used in the study. Present data clearly show that improved gas production, DM digestibility and cellulolytic enzyme activity by Tween 80 is not due to increased bacterial adhesion on the substrates.

• Korean Journal of Food Science and Technology
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• v.30 no.4
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• pp.908-915
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• 1998

By using Korean native soybean, traditional meju was prepared in Chuncheon, Kangweondo according to the traditional process. Analysis of physico-chemical, enzymatic and microbiological changes during meju fermentation were carried out in order to obtain a basic information for industrial scale production of meju. The enviroments for natural meju fermentation were $10{\sim}15^{\circ}C$ and $60{\sim}70%{\;}RH$. Moisture content decreased from 59% to 11% (exterior section) and 19% (interior section). the pH of meju rapidly increased up to 8.5 at $33^{rd}{\;}day$ of fermentation and thereafter decreased down to 7.9 at $70^{th}{\;}day$ of fermentation. Souble protein content was 1.47% at initial stage and increased up to $6.31{\sim}7.34%$ at $33^{rd}{\;}day$ of fermentation. Amino nitrogen content was $460{\sim}770{\;}mg%$ at $70^{th}{\;}day$ of fermentation. the color of meju became gradually black and decreased in redness and yellowness. During the process, protease and lipase seemed to play an important role in the digestion of soy protein and fat. Acidic protease activity increased up to $135.9{\sim}152.4{\;}unit/g$ at $33^{rd}{\;}day$ of fermentation and were $181.3{\sim}272.6{\;}unit/g$ at $70^{th}{\;}day$ of fermentation. Lipase activity increased up to 6 unit/g (interior section) and 15 unit/g (exterior section) at $70^{th}{\;}day$ of fermentation. the viable cell count of meju was at the level of $10^8{\;}CFU/g$ during the overall fermentation period. Aerobic halophilic count was $1.51{\times}10^7{\;}CFU/g$ at initial stage and maintained $10^8{\;}CFU/g$ level during the process. Initial anaerobic cell count was $2.0^9{\times}10^4{\;}CFU/g$ and increased up to $10^5{\;}CFU/g$ level at 47 days. Yeast and mold counts were $10^4{\sim}10^5{\;}CFU/g$ for the fermentation period.