재조합 미생물, Escherichia coli MT201를 이용한 L-Threonine 생산성 향상

하정욱,이만효,김기운,황용일 慶南大學校 附設 基礎科學硏究所 2002 硏究論文集 Vol.16 No.-

의료 및 가축사료용으로 폭 넓은 용도를 지니는 _L-threonine의 대량생산을 위하여 _L-aspartate 생합성계 대사 변이주이며 _L-threonine 생산균주로 개량된 E. coli MT201를 이용하였다. _L-Threonine의 생산성 향상을 위한 일환으로 C. glutamicum으로부터 정제·회수된 pyruvate carboxylase 구조유전자 ORF를 E. coli 발현용 plasmid pTrc99A에 도입하여 plasmid pPC를 제작하였다. 변이주 E. coli MT201 균주에 plasmid pPC를 형질전환법으로 도입하여 과량의 _L-threonine을 생산하는 우수한 재조합 균주인 E. coli MT-pPC을 얻었다. Glucose를 단일 탄소원으로 사용하였을 경우 균체의 생육 및 _L-threonine의 생산량이 감소하는 경향을 보였다. 이를 극복하기 위하여 glucose와 citrate(sodium citrate와 ammonium citrate)를 각각 첨가한 결과 sodium citrate에서 우수한 결과를 flask배양을 통하여 관찰하였다. 적절한 sodium citrate의 첨가 비는 탄소원인 glucose와 sodium citrate의 첨가비가 3.5:1.5일 때 _L-threonine 생산량과 생육이 월등히 향상되었다. 이를 바탕으로 발효조를 이용한 유가배양에서 생산량 75.7g/L를 얻었다. 따라서 본 실험을 통하여 _L-threonine의 생산량이 획기적으로 증가하는 재조합 균주를 개발하였고 생산량도 향상시켰다. _L-Threonine, which is used in the medical field for amino acid infusion and in feedstuff for livestock, is an essential amino acid for man and animals. Microorganisms are genetically bred for industrial production of amino acids including _L-threonine. In this study, Escherichia coli MT201, which was obtained with the view of overproducing for _L-threonine, is the metabolic mutant for a biosynthetic pathway of aspartate family. E. coli MT-pPC was obtained for the improvement of _L-threonine production by introducing plasmid pPC, which is an expression vector for pyruvate carboxylase coding gene(pyc) of Corynebacterium glutamicum ATCC13831 at E. coli MT201 strain. When only glucose was used for carbon source in E. coli MT-pPC, cell growth and _L-threonine production was reduced. For solving this problem, we added glucose and citrates in culture media. From the results, sodium citrate was more effective than ammonium citrate and the optimal ratio, which was the most efficient among those ratio employed here, was the 3.5 : 1.5 of glucose to sodium citrate. In our experiment, _L-threonine production, which was 75.7 g/L for 86 hr by E. coli MT-pPC added with 3.5 : 1.5 ratio of the glucose to sodium citrate in fed-batch culture, and these were higher than 1.2 fold of E. coli MT201 and 3.2 fold of E. coli MT-pPC, respectively, in glucose.

급성 심근경색증에 동반된 승모판 폐쇄부전증의 임상적 특징

정상만,조영일,조화상,유광하,송기호,인행환 건국대학교 의과학연구소 1997 건국의과학학술지 Vol.- No.7

한국의 부실채권발생 이유는 무엇인가? : 도산 예측에 있어서 회계자료의 유용성과 신용평가 MODEL의 유효성 Utility of Accounting data and Usefulness of Credit Evaluation MODELs

현영하,조정만 昌原大學校 産業經濟硏究所 2002 産經硏究 Vol.19 No.-

한국 대표팀과 세계 상위 랭커의 핸드몰 경기 분석에 관한 연구

두만균,오용기,박종하 圓光大學校 附設 體力科學硏究所 2005 體力科學硏究 Vol.28 No.-

The subjects of this study are the female handball players of 7 high ranking countries and Korea who participated in the Sydney Olypics 2002 in Australia. Upon closing of the Olympics, an analysis was conducted into the data which were released by IHF in connection with the outcomes of the games between the Korean female handball team and other seven participating countries. The results of the analysis by item are shown below-. 1. From the comparison of attacking power by type and position of each Korean female handball player, no significant difference was found generally except for 6M shoots and feint shoots in a 1 to 1 confrontation, which showed a slight difference(p<.05). In terms of the outcomes by position, players in R·B position were analyzed to record high average in 6M and 9M shoots. while players in C·B position scord high average in 7M shoots. As regards pointw. players in R·W position yielded average points. The speedy attacks appeared to record generally higher scores than other attacks. The players in R·W position scored high points in average. In regard of shoots and scores by feint attack in 1 to 1 confrontation, the players in P·V position showed fairly high average points. The players in C·B position scored higher points while those in R·W position demonstrated higher scording ratio in average. 2. From the analysis into the outcomes of the female handball games between Korea and 7 countries(Norway, Denmark, Rumania, Brazil, Angola, France and Hungary) at Sydney Olympics 2000, there was somewhat significant in terms of attacking position, while there was somewhat significant difference in scording by speedy attacks(p<.05). In detail, Rumanian team recorded higher average in 6M shoots while Danish team showed higher average in 9M position. Angola and Denmark yielded similar average scores in 9M attacks whereas Hungary showed generally low average in 7M Shoots and scores by wing attacks. Denmark got on scores by wing attacks. Hungary proved to be fairly good in feint attack in 1 to 1 confrontation and Brazil harvested a little higher shoots and scords in average.

國民學校 敎師의 科學敎育的 資質에 關한 調査硏究

金德萬,金容德,河炳權 서울교육대학교 과학교육연구소 1982 科學과 數學敎育 論文集 Vol.8 No.-

Escherichia coli(M15)을 이용한 serotonin N-acetyltransferase 유전자의 발현

김용만,정미영,윤경식,진병관,백행운,조용호,백형환 慶熙大學校 1997 論文集 Vol.26 No.-

AA-NAT cDNA was obtained by RT-PCR technique from total RNA of rat sacrified at night(02:00am). pCRNAT was cloned using the pCRII vector with insertion of AA-NAT cDNA(about 1.4 kb) at EcoRI site. For the expression of the gene, pQECNAT was subcloned, in which the coding region of AA-NAT was inserted into expression vector pQE30 at BamHI and HindIII sites. According to the experimental results, Escherichia coli strain M15, transformed by the expession vector pQECNAT, was selected as a host to express AA-NAT gene with the induction of isopropyl β-D-thiogalactoside(IPTG). Optimal condition for the expression of AA-NAT gene was achieve from the experimental results, showing that the expression of the protein was inducible much 19.800 ± 2,200 dpm per ml of culture volume in 4 hours at the concentration of 2 mM IPTG. Partial purification through the affinity column(Ni-NTA agarose) binding to the continuous 6 histidine residues of protein resulted in 5 times more increase in the specific activity of AA-NAT than that of the homogenate of bacterial pellet. These experimental results will provide basic data in further study for the enzymatic kinetics and antibody production of AA-NAT.

다수의 냉동시스템에 의한 저온 저장고의 에너지 성능평가

강동언,김성만,운종호,이의준,박영하,현명택 濟州大學校 産業技術硏究所 2000 산업기술연구소논문집 Vol.11 No.1

The cool storage system(CSS) is a specific building that is required only cooling load without heating during the whole year. CSS uses a electric energy which is very expensive and is required much amount of energy due to temperature differences between interior and ambient temperatures. The purpose of this study is to assess the energy performance of the multi-unit cooler operating control system. For the prediction of its performance, two types of test (KIER). First cell is equiped with one .are installed a t Korea Institute of Energy Research large unit cooler. and second cell consists of two small unit coolers. According to the results of experiments using these cells. the multi-unit cooler operating control system is found to be effective in energy saving and beneficial for storage due to much less deviation of temperature.

유연생산 시스템 구축을 위한 공작물 자동교환 유닛 설계

박후명,이용중,이상진,하만경 한국공작기계학회 2008 한국공작기계학회 춘계학술대회논문집 Vol.2008 No.-

The objective of this study is to develop an automatic object changer unit to improve processing problems existed in the conventional horizontal machining center. In order to perform this objective, a upward and downward traverse unit in which a unit that consists of a motor and reducer, chain and sprocket wheel, and upper and lower base employed in an automatic object changer unit performs sliding contact motion in a frame was designed. To achieve this design, constraint conditions for the upward and downward traverse unit first designed. Then, an operation mechanism was designed and that was introduced as a sum of kinetic energy for the sprocket wheel and upper and lower base based on the moment of inertia, which is the kinetic energy of the converted upward and downward traverse unit in the side of the reducer. In addition, The work required to rotate the converted upward and downward traverse unit in the side of the reducer by one revolution can be calculated using the sum of work that is required in the sprocket wheel and upper and lower base that is a part of the upward and downward traverse unit. Furthermore, the converted equation of motion in the side of the motor can be introduced using the equation of motion using the converted upward and downward traverse unit in the side of the motor. Then, Then, a proper motor can be determined using predetermined specifications employed in the motor and several parameters in the upward and downward traverse unit in order to verify such predetermined specifications. Also, a design of a horizontal traverse unit that performs sliding motion on a upward and downward traverse unit and simulation that verifies the results of this design are required as a future study.

Secretion amount of nectar a few medical herb plants in Korea

Ha sik-Sim,Man-young Lee,In-pyo Hong,Soon-ok Woo,Yong-soo Choi,Gyu-ho Byuon,Weon-ki Baiek,Young-ju Oh,Myeong-lyeol Lee 한국응용곤충학회 2013 한국응용곤충학회 학술대회논문집 Vol.2013 No.10

About 70% of total honey products produced by Korean bee keepers was acacia honey. The remaining 30% was chestnut honey, jujube honey, snowbell honey, and another honey. False acacia, went down in payability since the middle 2000s because of simultaneous blooming etiolation chlorsis decreases productivity after aging. Therefore, substitution honey plants were necessary. This study estimated nectar secretion amount of each flower and productivity per ha at 14 medical herbs. Each flower, Codonopsis lanceloata, estimated a majority nectar secretion amount at 176.08 ul for each of the 14 medical herbs. Astragalus membranaceus estimated majority nectar secretion amount at 1273.3 L per ha for each of the 14 medical herbs. Medical herbs were hypothesized with valuable honey plants.

Secretion characteristics of amount nectar Zizy jujube var. inermis in Korea

Ha sik-Sim,Man-young Lee,In-pyo Hong,Soon-ok Woo,Yong-soo Choi,Gyu-ho Byuon,Weon-ki Baiek,Young-ju Oh,Myeong-lyeol Lee 한국응용곤충학회 2013 한국응용곤충학회 학술대회논문집 Vol.2013 No.10

Jujube trees, herbal medicine material, produce not only their fruit but also jujube honey for bee and human’ food sources. Although jujube is an important honey plant after acacia bloom, the research was done with 15-year-old jujube trees grown in ChungDo-Gun, which there was no information on jujube floral nectar. According to the research, jujube nectar secretion mostly happens during dawn and morning for two days. The average number of inflorescence per tree is 638.1 according to the research. And also, the average number of flowers per inflorescence is 64.4. The amount of nectar secretion is 11.6 ul on average per flower, and hypothesized nectar secretion from 15-year-old tree per tree is 476.682 ul. Also,a jujube tree has 545.5ul hypothesized nectar secretion per ha by the research.