Development of Reproducible EST-derived SSR Markers and Assessment of Genetic Diversity in Panax ginseng Cultivars and Related Species

최홍일,김남훈,김준하,최범순,안인옥,이준수,양태진 고려인삼학회 2011 Journal of Ginseng Research Vol.35 No.4

Little is known about the genetics or genomics of Panax ginseng. In this study, we developed 70 expressed sequence tagderived polymorphic simple sequence repeat markers by trials of 140 primer pairs. All of the 70 markers showed reproducible polymorphism among four Panax species and 19 of them were polymorphic in six P. ginseng cultivars. These markers segregated 1:2:1 manner of Mendelian inheritance in an F2 population of a cross between two P. ginseng cultivars, ‘Yunpoong’ and ‘Chunpoong’,indicating that these are reproducible and inheritable mappable markers. A phylogenetic analysis using the genotype data showed three distinctive groups: a P. ginseng-P. japonicus clade, P. notoginseng and P. quinquefolius, with similarity coefficients of 0.70. P. japonicus was intermingled with P. ginseng cultivars, indicating that both species have similar genetic backgrounds. P. ginseng cultivars were subdivided into three minor groups: an independent cultivar ‘Chunpoong’, a subgroup with three accessions including two cultivars, ‘Gumpoong’ and ‘Yunpoong’ and one landrace ‘Hwangsook’ and another subgroup with two accessions including one cultivar, ‘Gopoong’ and one landrace ‘Jakyung’. Each primer pair produced 1 to 4 bands, indicating that the ginseng genome has a highly replicated paleopolyploid genome structure.

Energy and Environmental Benefits of Microalgal Biomass as a Direct Combustion Fuel

최홍일,심상준 한국공업화학회 2018 한국공업화학회 연구논문 초록집 Vol.2018 No.0

Microalgae have garnered considerable attention for their ability to produce various products utilizing CO₂. Especially, microalgae are considered to be the most promising candidate for biodiesel production platform. However, the production of biodiesel from microalgae requires cumbersome downstream stages, such as lipid extraction, trans-esterification and separation process, which negate CO₂ reducing effects and energetic benefit of the biomass energy source. In this point of view, the utilization of microalgal biomass as a direct combustion fuel is worth reconsidering. This is because it only needs simple dehydration system for the practical use. In this study, we studied the various benefits of microalgal biomass as a solid fuel. As a result, we found that microalgal biomass solid fuel chain is a practical CO₂-negative fuel system.

자기회귀교차지연 모형을 통한 청소년기 우울과 스마트폰 중독의 종단적 인과관계: 성별에 따른 차이 분석

최홍일,김병년 한국학교사회복지학회 2020 학교사회복지 Vol.0 No.50

This study examined autoregressive cross-lagged modeling of about 1,600 middle and high school students to verify the longitudinal influence relationship between smartphone addiction and depression. As a result of analysis, the level of smartphone addiction and depression at the previous time had a positive effect on the level of smartphone addiction and depression at the next time. Depression at the previous time also had a significant effect on the level of smartphone addiction at the next time. However, it was analyzed that the smartphone addiction of the previous time did not have a significant influence on the depression of the next time. And these results show that there is a difference in the magnitude of influence according to gender. This study prepared the theoretical and empirical basis for the necessity of intervention for reducing depression in smartphone addiction. In addition, as the difference between male and female students was identified in the cross-sectional relationship between depression and smartphone addiction, it was reported that the intervention between the two genders should be made differently. In addition, it was suggested that not only depression but also education to strengthen the ability to use smart phones should be provided both inside and outside the school. 본 연구는 스마트폰 중독과 우울 간의 종단적 영향력 관계 검증을 위해 한국청소년정책연구원에서 진행한 한국아동․청소년패널에 참여한 중․고등학생 약 1,600여명을 대상으로 자기회귀교차지연모형을 검증하였다. 분석결과 이전 시점의 스마트폰 중독과 우울 수준은 다음 시점의 스마트폰 중독과 우울에 정적 인 영향을 미치는 것으로 나타났다. 이전 시점의 우울은 다음 시점의 스마트폰 중독 수준에도 유의미한 영향력을 미치는 것으로 나타났다. 그러나 이전 시점의 스마트폰 중독은 다음 시점의 우울에 유의미한 영향력을 미치지 못하는 것으로 분석되었다. 그리고 이러한 관계에서 성별에 따른 차이는 유의미하지 않았으나 영향력의 정도는 남학생에서 높게 나타났다. 본 연구는 스마트폰 중독에 있어 우울 경감을 위한 개입의 중요성에 대한 이론적, 경험적 근거를 마련하였다. 또한 우울과 스마트폰 중독 간 관계에 대한 성별 차이의 경우 횡단적 연구에서 보고된 것과 달리 종단적 연구에서는 의미 있는 차이가 나타나지 않으며, 오히려 남학생에서 영향력의 정도가 더 높게 나타날 수 있다는 점이 제시되었다. 이를 통해 본 연구는 후속연구의 필요성과 더불어 우울뿐만 아니라 올바른 스마트폰 사용 역량 강화를 위한 교육이 학교 안팎을 통해 제공되어야 함을 제시하였다.

Quantitative Chemotaxis Analysis of a Model Microalga, Chlamydomonas reinhardtii, towards Bicarbonate with Agarose-Gel Microfluidic Device

최홍일,심상준 한국공업화학회 2018 한국공업화학회 연구논문 초록집 Vol.2018 No.0

Microalgae have attracted considerable attention for their ability to produce various products utilizing CO₂. Despite the importance, various biological phenomena are still unknown. Here, we examined the chemotaxis of C. reinhardtii towards HCO₃^- using a hydrogel (agarose)-based microfluidic device. The availability of the device was tested by previously studied chemicals: NH₄Cl and CoCl₂ are chemoattractants, while NaCl is neutral. We observed the chemotaxis of C. reinhardtii towards HCO₃^- and found the concentration for the strongest response. In diurnal chemotaxis assay, the chemotaxis peaked in the middle of the night while the response was quite low during the daytime. Furthermore, we verified several factors influencing on carbon concentrating mechanism (CCM) caused significant change in the chemotactic behavior. This study would provide a fundamental of HCO₃^--induced chemotaxis and may promote the understanding of inorganic carbon utilization.

Direct combustion opens up new possibilities for microalgae-based energy systems

최홍일,심상준 한국공업화학회 2018 한국공업화학회 연구논문 초록집 Vol.2018 No.1

Microfluidic-based screening strategy using chemotactic response of microalgae in a microdevice

최홍일,김영환,심상준 한국공업화학회 2016 한국공업화학회 연구논문 초록집 Vol.2016 No.0

We observed the chemotactic behavior of a motile microalga, Chlamydomonas reinhardtii, in a flow-based microsystem. According to the previous studies, C. reinhardtii utilizes carbon dioxide (CO2) and bicarbonate ion (HCO3-) as carbon sources at the same time. Firstly, we devised a microfluidic system which has three inlets for stable concentration gradient and 9 outlets for statistical analysis of the cell distributions. Pressure-driven flows were applied in the device by three syringe pumps and the cell numbers were counted at the entrance part of each outlet. We digitized the chemotactic responses of each strain by analyzing cell distributions. As a result, well-growing mutants had a tendency to prefer higher concentration. In other words, the chemotactic responses of well-growing mutants showed higher values. In addition, the correlations among the chemotactic response, △OD and Y(II) showed meaningful relationships.

2P-380 Quantitation of the Chemotactic Response of a Green Microalga, Chlamydomonas reinhardtii, to Bicarbonate Using a Novel Microfluidic Device

최홍일,심상준 한국공업화학회 2017 한국공업화학회 연구논문 초록집 Vol.2017 No.1

Microalgae have garnered considerable attention for their ability to produce various products utilizing CO₂. Despite the importance, various biological phenomena are still unknown. Here, we examined the chemotaxis of C. reinhardtii towards HCO₃^- using an agarose-based microfluidic device. The availability of the device was tested by previously studied chemicals: NH₄Cl and CoCl₂ are chemoattractants, while NaCl is neutral. We observed the chemotaxis of C. reinhardtii towards HCO₃^- for the first time and found the concentration for the strongest response. In circadian clock-related chemotaxis assay, the chemotaxis peaked in the middle of the night while the response was quite low during the daytime. Furthermore, we verified several factors influencing on CCM caused significant change in the chemotactic behavior. This study would provide a fundamental of HCO₃^--induced chemotaxis and may promote the understanding of inorganic carbon utilization.

Statistical analysis for screening microalgal strains based on their chemotactic responses in microfluidic devices

최홍일,장원석,심상준 한국공업화학회 2015 한국공업화학회 연구논문 초록집 Vol.2015 No.0

According to the previous studies, many aquatic photosynthetic organisms, such as microalgae utilize carbon dioxide (CO2) and bicarbonate (HCO3-) as carbon sources through CO2 concentrating mechanism. In this point of view, we tried to observe the existence of chemotaxis toward HCO3 - and verify the relationship between the extent of the chemotactic response and carbon dioxide fixation efficiency of the wild-type and mutants of a motile microalga, Chlamydomonas reinhardtii CC125 through various micro systems. As a result, we confirmed the microalga shows chemotactic response toward HCO3-. In addition, the correlations between the extent of chemotaxis and carbon dioxide fixation efficiency showed meaningful relationships. This result implies that this strategy can be used for high-throughput screening to find the microalgal strains with high CO2 fixation efficiency.

Microfluidic-based screening strategy using chemotactic response of microalgae for efficient CO₂ fixation

최홍일,성영준,김영환,심상준 한국공업화학회 2014 한국공업화학회 연구논문 초록집 Vol.2014 No.1

Chemotaxis is movement of an organism in response to a chemical signal. In this study, we observed the chemotactic behavior of a motile microalga, Chlamydomonas reinhardtii, in various systems. According to the previous studies, Chlamydomonas reinhardtii utilizes carbon dioxide (CO₂) and bicarbonate ion (HCO₃ ^-) as carbon sources at the same time. It is expected that the chemotactic response to HCO₃ ^- is related to the CO₂ fixation efficiency. Firstly, we devised a flow-free microfluidic system and observed the chemotactic response to the different concentrations of HCO₃ ^-. As a result, we found the most preferred concentration is 30mM. Based on this result, we designed a flowing system for strain screening. Well-growing mutants showed a tendency to prefer higher concentration. This result implies that the strategy can be used for high-throughput screening to find the superior microalgal strains with high efficiency of CO₂ fixation.

Quantitative analysis of chemotactic response towards bicarbonate and CO₂ fixation efficiency in Chlamydomonas reinhardtii

최홍일,노혜진,심상준 한국공업화학회 2019 한국공업화학회 연구논문 초록집 Vol.2019 No.0

Microalgae utilize carbon dioxide (CO₂) and bicarbonate (HCO3-) as carbon sources through CO₂ concentrating mechanism. In this study, we demonstrated the relationship between the extent of chemotactic response towards HCO3- and CO₂ fixation efficiency of the wild-type and mutants of Chlamydomonas reinhardtii CC125 in a microfluidic device. The movement of the microalgae was quantitatively evaluated by the degree of skewness and asymmetry of distribution. The results showed that the well-growing mutants had a tendency towards higher HCO3- concentration. In addition, the correlations between the chemotactic response and both the growth (△OD) and the photosynthetic efficiency (Y(II)) showed high linearities. This result implies that chemotaxis can be used as a strategy for high-throughput screening to identify microalgal strains with high CO₂ fixation efficiency.