• Journal of Life Science
• /
• v.27 no.3
• /
• pp.339-345
• /
• 2017

Carotenoids are natural lipid-soluble pigments, which are produced primarily by bacteria, algae, and plants. Many studies have focused on the identification, production, and utilization of natural sources of astaxanthin from algae, yeast, and crustacean byproducts as an alternative to the synthetic pigment, which is mostly used today. The aim of the present study was to identify a mutant of Paracoccus haeundaensis by exposure to UV and ethyl methanesulfonate (EMS). The mutant was then exposed to nutrient stress conditions to isolate an astaxanthin-hyperproducing strain, followed by characterization of the mutant. The survival rate decreased in accordance with an increase in the UV exposure time and an increase in the EMS concentration. A mutant of the original P. haeundaensis strain was identified that showed hyperproduction of astaxanthin following exposure to UV irradiation (20 min) and EMS treatment (0.4 M concentration). The optimal culture conditions for the PUE mutant were $25^{\circ}C$, pH 7-8, and 3% NaCl. The effects of various carbon and nitrogen sources on the growth and astaxanthin production of PUE were examined. The addition of 1% raffinose and 3% potassium nitrate influenced cell growth and astaxanthin production. The selected mutant exhibited an increase of 1.58 folds in astaxanthin content compared to initial wild type strain. A genetically stable mutant strain obtained using mutagen (UV irradiation and EMS treatment) may be a suitable candidate for further industrial scale production of astaxanthin.

• Korean Journal of Microbiology
• /
• v.46 no.2
• /
• pp.183-191
• /
• 2010

In this study, we isolated 179 bacterial strains using benzene, phenol, ethylbenzene, aniline, cumene, toluene as growth substrate from TCE contaminated soils and wastewaters. All the 179 strains were screened for TCE (30 mg/L) removal (growth substrate 0.2 g/L, $30^{\circ}C$, pH 7, cell biomass 1.0 g/L (w/v)) under aerobic condition for 21 days. EK2 strain using aniline showed the highest removal efficiency (74.4%) for TCE degradation. This strain was identified as Delftia acidovorans as the results of API kit, 16S rDNA sequence and fatty acid assay. In the batch culture, D. acidovorans EK2 showed the bio-degradation for TCE in the various TCE concentration (10 mg/L to 200 mg/L). However, D. acidovorans EK2 did not show the bio-degradation in the TCE 250 mg/L. D. acidovorans EK2 also show the removal efficiency (99.9%) for 12 days in the low concentration (1.0 mg/L). Optimal conditions to degrade TCE 200 mg/L were cell biomass 1.0 g/L (w/v), aniline 0.5 g/L, pH 7 and $30^{\circ}C$. Removal efficiency and removal rate by D. acidovorans EK2 strain was 71.0% and 94.7 nmol/h for 21 days under optimal conditions. Conclusion, we expect that D. acidovorans EK2 may contribute on the biological treatment in the contaminated soil or industrio us wastewater.

• Journal of Life Science
• /
• v.23 no.5
• /
• pp.676-681
• /
• 2013

Perchlorate (${ClO_4}^-$) is an emerging contaminant found in surface water and soil/groundwater. Microbial removal of perchlorate is the method of choice since perchlorate-reducing bacteria (PRB) can reduce perchlorate to harmless end-products. A previous study [3] showed experimental evidence of autotrophic perchlorate removal using elemental sulfur granules and activated sludge. The granular sulfur is a relatively inexpensive electron donor, and activated sludge is easily available from a wastewater treatment plant. A batch test was performed in this study to further investigate the effect of various environmental parameters on the perchlorate degradation by sludge microorganisms when elemental sulfur was used as electron donor. Results of the batch test suggest optimum conditions for autotrophic perchlorate degradation by sludge microorganisms. The results also show that sulfur-oxidizing PRB enriched from activated sludge removed perchlorate better than activated sludge. Taken together, this study suggests that autotrophic perchlorate removal using elemental sulfur and activated sludge can be improved by employing optimized environmental conditions and enrichment culture.

• Korean Journal of Food Science and Technology
• /
• v.45 no.1
• /
• pp.77-83
• /
• 2013

In this study, we observed optimal conditions and suitable bacteria for the fermentation of steam-dried ginseng berry extracts (SGB) and determined antioxidant effects of the fermented extracts. Five bacteria (Lactobacillus fermentarum, L. plantarum, L. brevis, L. casei, Bacillus subtillis) were examined on their growth activities and viabilities in various culture temperatures ($25-35^{\circ}C$) and concentrations (25-100%). L. plantarum was considered to be the most suitable bacteria for the fermentation in both growth activity and viability. Moreover, the extracts fermented with L. plantarum showed more potent antioxidant efficacy in both 1,1-diphenyl-2-picrylhydrazyl radical and hydroxyl radical scavenging assay. High performance liquid chromatography analysis revealed that fermentation with L. plantarum changed the contents and components of ginsenosides. In conclusion, these data suggest that L. plantarum efficiently ferment SGB and the fermented extracts may have therapeutical values against oxidative stress and be a good candidate in adjuvant therapy where ginsenoside would be the main composition.

• Korean Journal of Plant Resources
• /
• v.36 no.5
• /
• pp.527-539
• /
• 2023

Pepper (Capsicum annuum L.) is an important vegetable and spice crop that has been cultivated worldwide. Pepper fruits have unique taste and aroma, providing a variety of antioxidants and compounds important for human health, which makes a high economic value. In addition, there is a high demand for new pepper varieties, according to consumer's preference. However, pepper is a recalcitrant plant for in vitro tissue and organ differentiation and plant regeneration, which makes it difficult to develop demanded varieties using newly developed technologies such as genetic engineering and gene editing. In this study, tissue culture and regeneration conditions were investigated using seven pepper varieties that were obtained from the core-collection of Seoul National University. We observed callus and bud induction and shoot formation using several media composition composed of different cytokinins and auxin concentrations. As a result, it was found that there were differences in callus induction and shoot formation of each variety depending on the hormone composition, and the highest regeneration was shown when the medium containing Zeatin Riboside and the petioles of seedlings were used. In particular, out of seven pepper varieties, CMV980 exhibited a higher regeneration efficiency (approximately 48%) than other varieties, followed by Yuwolcho. Therefore, this study provides CMV980 and Yuwolcho as good candidates that can be used for pepper transformation, which might contribute to the development of various varieties through gene editing technology in the future.

• Korean Journal of Plant Resources
• /
• v.25 no.2
• /
• pp.225-231
• /
• 2012

To figure out optimum culturing condition for $in$ $vitro$ yam ($Dioscorea$ $opposita$ Thunb.) production, various media components and environmental controls were evaluated, effective temperature, light condition and timing of the liquid media replacement for multiplication of yam in liquid culture were determined in this study. There was no visible difference detected for $15^{\circ}C$ and $25^{\circ}C$ temperature conditions. At $25^{\circ}C$, continuous light condition was more effective compared to 16 hour light/ 8 hour dark condition. Effect of media replacement was tested, and approximately 5 more microtubers obtained and 70% of increase in weight was detected when media replacement was performed. Timing for media replacement was tested at 2, 4, 6, 8, and 10 weeks after initial culture for 12 weeks. Considering both number and weight of microtubers, replacement of media 6 weeks after initial culture was most effective. In terms of component of media, significant increase in weight of microtubers was observed in MS media containing sucrose $60g{\cdot}L^{-1}$. In summary, the most effective condition for $in$ $vitro$ propagation of chinese yam is replacing medium 6 weeks after initial inoculation with MS medium containing sucrose $60g{\cdot}L^{-1}$ in continuous light condition.

• Korean Journal of Medicinal Crop Science
• /
• v.1 no.2
• /
• pp.137-157
• /
• 1993

This study was carried out to investigate the optimal condition for multiple propagation through leaf tissue culture and to apply anther culture techniques to Pulsatilla koreana Nakai breeding. Leaf and anther of Pulsatilla koreana Nakai were cultured on MS, MT, LS and $B_5$ media supplemented with several growth regulators and nitrogen sources under various conditions. For callus induction and differentiation from the Pulsatilla koreana leaf segments were more effective in the combination of zeatin and auxin than auxin alone. The color of the callus was green when treated with IBA alone. Shoot differentiation was more effective when treated with zeatin than auxin alone, especially the best hormoal combination for shoot differentiation was zeatin 1.0mg/l +NAA 0.1mg/l, while 2,4-D inhibited shoot differentiation. The appeared rate of S pollen was 35% in vivo, while that of S pollen by low temperature$(4^{\circ}C)$ pretreatment for 4 days was increased by 53% and the optimum culture time for callus induction from anther was uni-nucleate stage. $B_5$ basal medium supplemented with NAA 0.5mg/l and zeatin 1 mg/l was the most effective on callus formation and the best results of plant regeneration were obtained from combination of NAA 0.5mg/l and zeatin 0.5mg/l in anther culture. $NH_{4}NO_3$ as more effectives as the nitrogen source than $KNO_3$ and the combination with zeatin 2.0mg /L was the best effective. The best combination for plant regeneration in callus induced from anther was $NH_{4}NO_3$ 1650mg/l + $KNO_3$ 3800mg/l + zeatin 2.0mg/l. Ploidy level of anther-derived plants appeared 28% haploid, 47% diploid and the others were triploid, tetraploid and mixploid. In compare with E.S.T, M.D.H and P.X banding patterns were distinguished among callus, haploid and diploid plants in electrophoresis.

• Journal of the Korean Society of Costume
• /
• v.17
• /
• pp.29-43
• /
• 1991

Yu was a type of dress worn on the upper part of the body which was commonly used in Northeast Asia. It was originally used by the Northern race for the need of courtesy as well as protecting cold. It was believed that Yu in Northeast Asia, which was called Kaftan, was came from Scythai lived in North Eurasian land around the Black sea. Scythians were the first-formed horse-riding race in the world and their civilization influenced those of far Asiatic sector along the steppe route. As their power expanded, their costume culture transmitted to the East(China, Korea, Japan). The upper garment, Yu, was characterized by the left-sided collars, narrow sleeves belted at the waist to the length of the hip line and the tight trouser on the lower part, which we commonly called HoBok(胡服) style. 1. Yu in Northeast Asia was originated from the Eurasians, Scythian Culture. Being exchanged, active style costumes were widely used among Chinese, Koreans and Japanese throughout centuries' including $4{\sim}8$ century. 2. Chinese Yu had a style of wide-sleeves and right-sided collars. The traditional costumes of Han race are consisted of wide-sleeved Yu on the upper and long-skirt on the lower part of the body. Before the adoptation of HoBok during reign of King Jo Mooryung in 307. B.C., HoBok style had already found in the remains since the Sang period. There were various names among Yu during the Han period. Seup, Sean Eui, Kye, Kyu were one of the styles and several names were meant for collar and sleeves. During $4{\sim}8$ centuries, clothes of right-sided collar were found, superior to that of left-sided and narrow sleeves were widely used both the royal and the humble. Various styles of decoration were seen in Yu around neck, back and sleeves comparing other nations. 3. Yu, in Korea, was typical style of Northern-bound HoBok. Both men and women had similarity in Yu style, narrow sleeves, left-sided collar, belted at the waist and to the length of hip line. Influenced by Han race, in the $4th{\sim}8th$ centuries, dual system of collar was found. But we cannot see major change in Yu and finally was connected to the present. 4. The original design of the Japanese costumes was not similar to that of Northern nomadic hunting race, which was suitable for horse-riding activities. Owing to the climates along the island, we could see various conditions ranging from the cold and to the warm. Influenced by the climates, pulling over the neck(Pancho style) were major design in Japan. As Korea was advanced earlier than Japan, Korean landed Japanese territory showing clothes. So primitive costumes had changes in style. During the $4th{\sim}8th$ period. The Korean mode was found in Haniwa (which was built to make sacrifices to the dead King) and costumes in Jeong Chang Won. Among the costumes in Jeong Chang Won, we put 3 or more costumes to the category of Yu characterizing elements of Korea and Tang period. From the $4th{\sim}8th$ century, China, Korea, Japan fell into the same cultural category, Scythai. Styles in Yu among three nations, we saw little differences, basically along times. Originated from the West Asia, Yu was transmitted to the far East changing Chinese costumes, Koreans melted it into the traditional elements and then influenced Japan.

• Journal of Marine Life Science
• /
• v.9 no.1
• /
• pp.9-21
• /
• 2024

Paralytic shellfish poisoning (PSP) including Saxitoxin (STX) is caused by harmful algae, and poisoning occurs when the contaminated seafood is consumed. The mouse bioassay (MBA), a standard test method for detecting PSP, is being sanctioned in many countries due to its low detection limit and the animal concerns. An alternative to the MBA is the Neuro-2a cell-based assay. This study aimed to establish various test conditions for Neuro-2a assay, including cell density, culture conditions, and STX treatment conditions, to suit the domestic laboratory environment. As a result, the initial cell density was set to 40,000 cells/well and the incubation time to 24 hours. Additionally, the concentration of Ouabain and Veratridine (O/V) was set to 500/50 μM, at which most cells died. In this study, we identified eight concentrations of STX, ranging from 368 to 47,056 fg/μl, which produced an S-shaped dose-response curve when treated with O/V. Through inter-laboratory variability comparison of the Neuro-2a assay, we established five Quality Control Criteria to verify the appropriateness of the experiments and six Data Criteria (Top and Bottom OD, EC₅₀, EC₂₀, Hill slop, and R² of graph) to determine the reliability of the experimental data. The Neuro-2a assay conducted under the established conditions showed an EC₅₀ value of approximately 1,800~3,500 fg/μl. The intra- & inter-lab variability comparison results showed that the coefficients of variation (CVs) for the Quality Control and Data values ranged from 1.98% to 29.15%, confirming the reproducibility of the experiments. This study presented Quality Control Criteria and Data Criteria to assess the appropriateness of the experiments and confirmed the excellent repeatability and reproducibility of the Neuro-2a assay. To apply the Neuro-2a assay as an alternative method for detecting PSP in domestic seafood, it is essential to establish a toxin extraction method from seafood and toxin quantification methods, and perform correlation analysis with MBA and instrumental analysis methods.

• Korean Institute of Interior Design Journal
• /
• no.14
• /
• pp.82-89
• /
• 1998

During the boom of museum building in the 1970s-80s two museum wee erected in Germany. They are James Stirling's Neue Stattsgalerie Stuttgart and hans Hollein's Stadtisches Museum Abteiberg Monchengladbach, These two museums share the folowing point of similarity : Stirling's Neue Stattsgalerie Stuttgart and Hollein's Staditisches Museum Abetiberg Monchenbladbach both manifest the conditions of the times in light of their respective cities' local characters and historical contexts without being bound to traditional formality. Stirling and Hollein attempted to grasp the meaning of the 기nuseum as a city in miniature." Taking into account the t two museums’s territorial characteristics of being situated on a slope, both Stirling and Hollein made the walker to pass t through their building complex and introduced the concept of a public square within them. As a result, the museums are not j just two large buildings but are architecture composed of a collage of various structures. S Stirling’s architecture employs the method of attaching additional elements on top of basic constituents, which is suggestive '||'&'||'#61551; of the historical fragment from Shinkel's Altes Museum. On the other hand, Hollein applies a collage-style method as if he w were doing urban planning, maintaining the distinctiveness of each of the various forms and materials of buildings. T The object style buildings of the two museums actively demonstrate the contrast of double meaning to represent the a ambiguous and multifarious characteristics of the modern times. Stirling explores the theme of opposition and coexistence in h his Neue Stattsgalerie Stuttgart by placing a series of opposing concepts, such as the past and present and histor${\gamma}$ and t technology, in one space. Thereby, the contradiction and its appeal are manifested. Hollein made use of the visual illusion and c contradiction in alluding to the irony of the modern reality induced by nature and culture and history and technology. F For the above reasons and methods, James Stirling ’ s Neue Stattsgalerie Stuttgart allowed the penetration of art into daily l life and became the general public’s favored museum for its free and unrestrained environment. Likewise, Hans Hollein’s S Stadtisches Museum Abteiberg Moncbengladbach contribute to the development of museum function as it an expression of art i in the form of a complex piece of scupture on its own.ts own.