• Journal of Microbiology and Biotechnology
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• v.30 no.6
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• pp.868-877
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• 2020

Bicarbonate has been considered as a better approach for supplying CO₂ to microalgae cells microenvironments than gas bubbling owing to cost-effectiveness and easy operation. However, the β-carotene production was too low in Dunaliella salina cultivated with bicarbonate in previous studies. Also, the difference in photosynthetic efficiency between these two carbon sources (bicarbonate and CO₂) has seldom been discussed. In this study, the culture conditions, including NaHCO₃, Ca²⁺, Mg²⁺ and microelement concentrations, were optimized when bicarbonate was used as carbon source. Under optimized condition, a maximum biomass concentration of 0.71 g/l and corresponding β-carotene content of 4.76% were obtained, with β-carotene yield of 32.0 mg/l, much higher than previous studies with NaHCO₃. Finally, these optimized conditions with bicarbonate were compared with CO₂ bubbling by online monitoring. There was a notable difference in F_v/F_m value between cultivations with bicarbonate and CO₂, but there was no difference in the F_v/F_m periodic changing patterns. This indicates that the high concentration of NaHCO₃ used in this study served as a stress factor for β-carotene accumulation, although high productivity of biomass was still obtained.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.8 no.2
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• pp.12-17
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• 2002

Since 1985, the growth rate of population of the world is over that of the food production. The cultivated land and the grain production rate are decreasing every year. Therefore, the most serious crisis which we will meet in the 21st century will be food shortage. In order to solve this desperate shortage of food, besides trying to produce more food, the technology of post-harvest, food processing, and food packaging should be developed to reduce and make the best use of the amount of the already produced agricultural products for which a lots of cost and labors were invested, but are being wasted during food distribution channel due to their undeveloped technology.

• Current Research on Agriculture and Life Sciences
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• v.33 no.2
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• pp.37-40
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• 2015

Poria cocos is an edible and pharmaceutical mushroom with a long history of medicinal use in Korea. For the last 30 years, the domestic cultivated supply of Poria cocos has been unable to meet consumer demand, so Poria cocos is collected in mountainous areas and also imported from China. Thus, to increase the supply of Poria cocos, many artificial cultivation methods have been studied. In this study, Poria cocos is cultivated under different environmental conditions using plastic bags and the results compared. When cultivating Poria cocos at different temperatures (20, 25, 30 and $35^{\circ}C$) and using different numbers of plastic bag layers (1, 2), the most efficient cultivation conditions were a temperature of $25-30^{\circ}C$ and 2 plastic bag layers. The fastest growth was at $25-30^{\circ}C$, and the Poria cocos exhibited no weight change when cultivated using layers of plastic bags (1, 2).

• Horticultural Science & Technology
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• v.31 no.2
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• pp.231-238
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• 2013

Perilla frutescens, which comprises var. frutescens and var. crispa, has been cultivated traditionally in Asian countries as an edible oil, leaf vegetable, and medicinal crop. To evaluate the lipophilic phytonutrient properties of P. frutescens, we selected 54 Perilla accessions [19 landraces of var. frutescens (FL), 22 weedy type var. frutescens (FW), 9 weedy type var. crispa (CW), 2 cultivars of var. frutescens widely cultivated for seed oil (FCS), and 2 cultivars of var. frutescens cultivated as a leaf vegetable (FCL)] and analyzed their seeds and leaves for vitamin E, squalene, and phytosterols. Among the four vitamin E isomers analyzed, ${\gamma}$-tocopherol was the major form of vitamin E in seeds, whereas ${\alpha}$-tocopherol was the major form in leaves of all types of P. frutescens. The highest total vitamin E content in seeds was present in FL ($170.0mg{\cdot}kg^{-1}$), whereas that in leaves was highest in FCL ($358.1mg{\cdot}kg^{-1}$). The highest levels of squalene in seeds and leaves were in FL ($65.5mg{\cdot}kg^{-1}$) and CW ($719.3mg{\cdot}kg^{-1}$), respectively. Among the three phytosterols, ${\beta}$-sitosterol occurred in the highest amount in both leaves and seeds of all of the crop types. Phytonutrient contents were comparatively higher in leaves than in seeds of all crop types. All of these results suggest that the consumption of leaves and seeds of Perilla crops could be beneficial to human health, as Perilla possesses considerable amounts of various lipophilic compounds.

• BMB Reports
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• v.38 no.3
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• pp.307-313
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• 2005

Thiobacillus ferrooxidans is one of the most important bacterium used in bioleaching, and can utilize $Fe^{2+}$ or sulphide as energy source. Growth curves for Thiobacillus ferrooxidans have been tested, which show lag, logarithmic, stationary and aging phases as seen in other bacteria. The logarithmic phases were from 10 to 32 hours for Thiobacillus ferrooxidans cultivated with $Fe^{2+}$ and from 4 to 12 days for Thiobacillus ferrooxidans cultivated with elemental sulphur. Differences of protein patterns of Thiobacillus ferrooxidans growing on elemental sulphur and $Fe^{2+}$ separately were investigated after cultivation at $30^{\circ}C$ by the analysis of two-dimensional gel electrophoresis (2-DE), matrix-assisted laser desorption/ ionization (MALDI)-Mass spectrometry and ESI-MS/MS. From the 7 identified protein spots, 11 spots were found more abundant when growing on elemental sulphur. By contrast 6 protein spots were found decreased at elemental cultivation condition. Among the proteins identified, cytochrome C have been previously identified as necessary elements of electron-transfering pathway for Thiobacillus ferrooxidans to oxidize $Fe^{2+}$; ATP synthase alpha chain and beta are expressed increased when Thiobacillus ferrooxidans cultivated with $Fe^{2+}$ as energy source. ATP synthase Beta chain is the catalytic subunit, and ATP synthase alpha chain is a regulatory subunit. The function of ATPase produces ATP from ADP in the presence of a proton gradient across the membrane.

• Journal of Korean Society of Rural Planning
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• v.27 no.4
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• pp.33-41
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• 2021

Ammonia emission from the agricultural sector contributes almost 78% of total ammonia emission in Korea. The current ammonia emission estimation method from fertilizer application has high uncertainty and needs to be improved. In this study, we propose an improvement method for estimating the amount of ammonia emission from agricultural land with improved spatiotemporal resolution using Farm Manager Registration Information System and criteria for the fertilizer. We calculated ammonia emissions by utilizing the 2020 cultivation area provided by Farm Manager Registration Information System for 55 kinds of upland crops cultivated in the field area of the farmland. As a result, soybeans were the most cultivated field crop in 2020, and the area of cultivated land was surveyed at about 77,021 ha, followed by sweet potatoes 22,057 ha, garlic 20004 ha, potatoes 17,512 ha, and corn 16,636 ha. The month with the highest ammonia emissions throughout the year was calculated by emitting 590.01 ton yr-1 in May, followed by 486.55 ton yr-1 in March. Hallim-eup in Jeju showed the highest ammonia emission at 117.50 ton yr-1.

• Food Science and Preservation
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• v.31 no.2
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• pp.267-275
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• 2024

Artemisia fukudo Makino belongs to the Asteraceae family, is a halophyte that can grow in salinity soils and is known for its various physiological activities. However, few studies were comparing it according to the growth environment. Therefore, in this study, we analyzed the antioxidant activity, functional ingredients, and safety of Artemisia fukudo Makino according to the growth environment. Total polyphenol content was the highest in native mature leaves, but 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) and 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity was higher in cultivated leaves than in native leaves. The total mineral content, excluding sodium, was higher in cultivated than in native leaves. The content of potassium and calcium was higher in cultivated leaves than in native leaves. In addition, heavy metal analysis showed that cultivated leaves were generally lower than those of native leaves. Residual pesticides were not detected in all samples. In conclusion, since there is no significant difference in cultivated leaves compared to native leaves, it was judged that cultivated leaves could be used as a variety to be grown and mass-produced.

• Korean Journal of Food Science and Technology
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• v.26 no.5
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• pp.512-519
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• 1994

To investigate the effects of cultivation on the aroma characteristics of essential oil of peppermint (Mentha piperita L.), experimental peppermints were cultivated with different treatments of field mulching, soil fertilization, and harvesting time. Aroma characteristics of the different mint oils were analyzed by gas chromatography (GC) and GC/mass spectrometry (MS)/infrared spectroscopy (IR). Growth of peppermint with vinyl muching was faster in the early stage of cultivation, but became almost same in the harvest date. The higher amounts of rainfall and sunshine hour resulted in the better growth of stem and leaf of the peppermint. Contents of menthone in the essential oils from the peppermint cultivated in 1990 increased as harvest date delayed from late June 25 to late July 26 the same period. In 1991 menthone decreased from June 25 to August 5, but l-menthol increased from June 25 to august 5. The results indicated that the sunshing hour affected biosynthesis of the components. Contents of menthofuran increased significantly from early June to late July. The optimum cutting date resulting best oil production was late July 7 in 1991.

• Journal of the Korean Wood Science and Technology
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• v.47 no.3
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• pp.360-370
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• 2019

Woody crops cultivated in short-rotation coppices are attractive sources of lignocellulosic materials for bioethanol production, since they are some of the most abundant renewable resources. In this study, we evaluated the effects of the growth period on bioethanol production using short-rotation woody crops (Populus nigra ${\times}$ Populus maxiwiczii, Populus euramericana, Populus alba ${\times}$ Populus glandulosa, and Salix alba). The carbohydrate contents of 3-year-old and 12-year-old short-rotation woody crop branches were 62.1-68.5% and 64.0-67.1%, respectively. The chemical compositions of 3-year-old and 12-year-old short-rotation woody crop branches did not vary significantly depending upon the growth period. However, the 3-year-old short-rotation woody crop branches (glucose conversion: 26-40%) were hydrolyzed more easily than their 12-year-old counterparts (glucose conversion: 19-24%). Furthermore, following the fermentation of enzymatic hydrolysates from the crop branch samples (by Saccharomyces cerevisiae KCTC 7296) to ethanol, the ethanol concentration of short rotation coppice woody crops was found to be higher in the 3-year-old branch samples (~ 0.18 g/g dry matter) than in the 12-year-old branch samples (~ 0.14 g/g dry matter). These results suggest that immature wood (3-year-old branches) from short-rotation woody crops could be a promising feedstock for bioethanol production.

• Journal of the Korean School Mathematics Society
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• v.25 no.2
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• pp.195-224
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• 2022

In this study, pre-service mathematics teachers cultivated technology content teaching knowledge (TPACK) in the regular curriculum of the College of Education. The course was designed to enhance pre-service teachers' mathematical communication skills by using an application, which is a mobile mathematics learning content for the development of group creativity of high school students. The educational program to improve mathematics teaching expertise using the application for group creativity expression consists of pre-education, goal setting, planning, teaching at school, and evaluation. In this process, pre-service teachers evaluated technology tools. They also wrote a task dialogue, lesson play, reflective journal, and lesson plan to guide high school students to develop group creativity in both app activities. As a result of the educational program, pre-service mathematics teachers cultivated TPACK and enhanced their mathematical communication skills with high school students to develop group creativity.