Production and Characterization of Enzymes Involved in Chitin Catabolic Cascade from a Bacterial Strain Isolated from Soil

( Ji Hyun Lee ),( Jeong In Lee ),( So Yeon Park ),( Yoo Kyeong Jang ),( You Bin Lim ),( Hye Yoon Lee ),( Young Min Jung ),( Hae Chang Lee ),( Jong Hwa Lee ),( Shaheen Amna ),( Jae Kweon Park ) 한국키틴키토산학회 2019 한국키틴키토산학회지 Vol.24 No.1

The present study was aimed to isolate the bacteria producing chitinolytic enzymes including chitin deacetylase (CDA) from soil origin. About 24 bacteria were screened for their chitinolytic enzymes producing ability on the basis of colloidal chitin. Amongst one of the most potent isolates designated to JI-02 was further selected as the most prominent chitinolytic and CDAlike enzyme (CDA-X) producer based on the ability of deacetylation of an artificial substrate pNP-acetamilide. The maximum production of CDA-X in crude enzyme from JI-02 was observed in the presence of 1% colloidal chitin at 37°C and pH 6.4 after 120 h of incubation. Potent enzyme activity of CDA-X was determined toward pNP-acetamilide, demonstrating that optimal pH, temperature and ionic strength of the CDA-X were assessed to be 7.0, 52°C and 125 mM, respectively. Unexpectedly, Nacetylglucosamine (GlcNAc) was not fully converted by the action of CDA-X to glucosamine (GlcN) under the established conditions. Further study on enzyme activity toward chitin-oligosaccharides consisting of multi-N-acetylglucosamine (GlcNAc)n, n=2-5 may be necessary to elucidate the mode of action which requires the minimum size of (GlcNAc)n. However, our data suggest that CDA-X can convert chitin to chitosan with the maximum yield of approximately 0.08g/L during the fermentation of the strain in the presence of chitin. Furthermore, we found that crude enzyme showed the significant chitosanolytic activity. Taken together, our data suggest that the strain JI-02 may be a potential candidate as a particular strain for better understating of chitin catabolic pathway.

소형 브러시레스 모우터의 광범위 속도제어에 관한 연구

유지윤 國立 昌原大學校 産業技術硏究所 1989 産技硏論文集 Vol.3 No.-

The main subject of this paper is to examine the relationship among the torque, the speed and the temperature rising subjected to the light weight and small size condition. For this purpose, we examine mainly the temperature characteristics of the motor by both experiments and simulations. The investigations are carried out in the case of both the sinewave excitation and the squrewave excitation, for the control voltage scheme and control current respectibly. The examinations of the temperature characteristics in the control voltage scheme shows that the sinewave excitation is profitable in the low speed rigion, while the squrewave excitation in the high speed revolution. On the other hand, in the control current scheme, the sinewave excitation is most profitable, causing lower temperature rising owing to no harmonic components. This facts coincidents with the theoritical result deduced form the variational method. Finally, this paper describes the transient characteristics of the motor, which is obtained by means of simulation, for various excitation condition.

토양환경지도 자료를 이용한 콩밭 토양의 화학성 비교

박지숙,이민진,정재원,김미혜,이서연,지윤미,한준호,김유학,공명석,한광현,노희명 忠北大學校 農業科學硏究所 2015 農業科學硏究 Vol.31 No.2

It is important to interpret the soil chemical properties in order to effectively manage the farmland. This study was conducted to investigate the soil chemical properties of upland soybean field according to the soil series at 32 upland fields located in the parts of Gangwon-do. Soil sampling sites were selected by using the National Statistics DB and KSIS DB that is a soil environment information system provided by the Rural Development Administration. Soil samples were collected from 0~15 cm of top soil before seeding or transplanting, air-dried, passed through a 2 mm sieve, and analyzed for soil pH, EC, organic matter, available phosphorus (P2O5), exchangeable potassium, exchangeable calcium and exchangeable magnesium. The average chemical properties have exceeded the each nutrient optimum range level of RDA, except the organic matter in experimental soil 2015. And despite application of conventional fertilization, each soil series nutrient contents were change respectively. The results of this study suggest that conventional fertilization should be applied based on the analysis about the amount of accumulated nutrient contents in the soil.

석면함유 슬레이트 지붕 물받이 퇴적물 중 석면 섬유 함유율

임지현,한솔민,김현석,신유민,박시은,허정윤,김민영,장봉기 순천향대학교 기초과학연구소 2022 순천향자연과학연구 논문집 Vol.28 No.1,2

This study attempted to determine the degree of asbestos release from the aging slate roof by comparing the asbestos content in the slate roof rain gutter with a colored steel plate (tin plate) over the slate roof. Four slate roof houses located in Haengmok-ri, Asan-si, Chungcheongnam-do, and one house constructed with a colored steel plate on the slate roof were selected to collect the sediment of the roof rain gutter. The asbestos fiber content was calculated by a point counting method using a polarization microscope after pretreatment with conversion treatment and hydrochloric acid treatment. The average asbestos content of the four slate roof rain gutter were 1.89%. However, asbestos was not detected in the Slate covering roof rain gutter, which were constructed on the slate roof. Asbestos fiber content was the highest at 2.89% in the slate roof rain gutter installed in 1976, followed by 2.44% in 1953. From the above results, it is necessary to minimize secondary damage as asbestos fibers released from slate roof houses to the surrounding atmosphere or leaked from slate roofs as rainwater may cause soil pollution and seriously affect residents' health. Although covering with colored steel plates (tin plates) has been shown to prevent the leakage of asbestos fibers to some extent, it is believed that a policy alternative to remove the slate roof as soon as possible is needed to solve the fundamental problem.

환기용 팬의 유동특성에 관한 연구

유근종,윤지훈 國立 昌原大學校 産業技術硏究所 1999 産技硏論文集 Vol.13 No.-

Analysis of ventilation fan flow has been carried out using CFX CFD code. The ventilation fan is applied widely to enhance air flow in open space. Selection of the ventilation fan is an important factor to design air ventilation facility to control air quality. Therefore, the accurate flow analysis is required in process of proper ventilation fan selection. Detailed analysis of fan flow in open space has been performed for 4 different commercially available ventilation fan. Computed air velocities show typical jet flow characteristics. The fan flow expands up to 10m in both of lengthwise and spanwise direction. The analysis also shows that turbulent flow enhances mixing of air in the space. From the analysis, flow analysis using CFD method is found to be an effective tool to select a proper ventilation fan. However, further detailed analysis which includes mass transfer for prediction pollutant behavior is required to complete air quality analysis.

이문화 상호작용으로서 게스트-호스트 관계에 관한 연구

유지윤 한국문화관광학회 2001 문화관광연구 Vol.3 No.2

The favorable type of tourism has moved into alternative tourism from mass tourism. Tourists nowadays seek for closer interactions with people in host society more and more and prefer to have individualized and meaningful experience. The purpose of this study is to gain richer insight into host-guest interactions in international tourism in terms of intercultural and social contact. It is also to manifest development process of host-guest relations and the factors which affect the relational development. The research process includes review of the theories in intercultural interactions and social contact, and ethnographic interviews of 6 informants based on naturalistic inquiry paradigm. As a result of the study development process of the host-guest interactions is produced and 5 main factors which affect the relations are identified.

수완진동 증후군에서 신경장해의 조기진단을 위한 객관화된 방법

윤재국,이헌,최나리,김석환,박형욱,이지호,유철인 大韓産業醫學會 2009 대한직업환경의학회지 Vol.21 No.2

목적: 통각과 진동감각 역치검사 및 수부와 수지의 악력, 그리고 수지의 운동기능검사(태평) 등과 근로자들이 호소했던 증상에 대한 HAVS의 스톡홀름 워크샵 분류와의 관련성을 통해 좀 더 객관화된 신경학적 조기검사 방법을 찾고 타당성을 검증하고자 하였다. 방법: 2000년 1월부터 2007년 12월까지 수부진동에 폭로되고 수부의 불편함을 호소하여 진동 장해에 대한 검사를 시행한 497명의 근로자를 대상으로 하였다. 일차적으로 문진을 통해 직업력에 대해 알아보고 과거력을 조사했다. 대상자들의 스톡홀름 워크샵 분류에 따른 소견을 확인하고 수부의 말초 순환기능 검사(손톱압박, 수지피부 온도), 신경기능 검사(통각과 진동각 역치), 운동기능 검사(악력, 태평) 등을 시행하였다. 다른 질환의 감별을 위한 몇 가지 이학적 검사를 실시하고 스톡홀름 워크샵 분류에 따른 검사 결과들을 분석하였다. 결과: 사용 도구는 그라인더 단독 사용이 265명 (67.3%)으로 가장 많았으며 평균 노출 연수는 14.8년이었다. 통각과 진동감각에서 스톡홀름 워크샵 분류 단계에 따른 역치가 증가하는 경향을 보였으나 통각은 양측 모두 통계적인 유의성이 없었고, 진동감각은 125와 250 Hz에서 양측 모두 유의했다(p=0.006-0.038). 수부와 수지의 악력은 단계가 올라갈수록 감소하는 경향을 보였지만 수부와 수지 모두 우측에서만 통계적으로 유의했다 (p=0.041, p<0.01, p=0.034). 태평 첫수는 단계가 올라 가면서 전반적으로 태핑 첫수가 감소하였으며 좌측에서만 통계적으로 유의했다(p=0.002-0.019). 결론: 본 연구는 수부 진동 노출자들의 수부 불편함에 대한 신경계통을 초기에 정량적으로 객관화하여 진단할 수 있는 단일 방법은 아직 없으며 일상생활의 불편함과 스톡홀름 워크샵 분류 등을 통한 주관적인 증상에 더하여 수지 통각과 진동감각 역치검사, 수부와 수지 악력검사, 운동기능검사(태핑) 등을 통합하면 초기에 객관적으로 진단하는 것이 가능할 것으로 판단된다. Objectives: In order to determine find out the best methods for a more objective detection of neurologic abnormality in early hand ann vibration syndrome(HAVS), early with analyzing the validity of each of the detection methods was analyzed. We evaluated the relationships between the sensorineural stage of Stockholm-revised vibration syndrome classification and the results of several tests. Methods: 497 workers were investigated for symptom, exposure duration, the types of tools used, and medical history from January 2000 to December 2007. Pain sense threshold, vibrotactile threshold, hand grasp force, finger grasp force, and a finger tapping frequency test were performed by the workers. Results: The grinder(67.3%) was the most commonly used tool and the mean exposure duration was 14.8 years. Although the pain sense and vibrotactile threshold level tended to increase according to sensorineural stage of the Stockholm classification, there was statistically significant difference in the vibrotactile threshold of 125, 250 Hz (P=0.006~0.038) but not in the pain sense threshold. Hand and finger grasp force tended to decrease according to the sensorineural stage of Stockholm classification and there was statistically significant difference(P=0.041, <0.001, 0.034) only on the right hand side. The tapping frequency also generally decreased according to the sensorineural stage of the Stockholm classification and there was statistically significant difference (P=0.002~0.019) only on the left hand side. Conclusions: Although there is no single standardized method that can objectively diagnose the Sensorineural component of early HAVS early, the combination of subjective symptoms, the sensorineural stage of Stockholm classification, the pain and vibrotactile threshold test, the hand and finger grasp force, and the finger agility (tapping) test can objectively detect sensorineural component of HAVS early.

조혈모세포이식 후 발생한 주폐포자층 폐렴에 대한 고찰

주지현,최정현,이동건,백지연,고윤호,이혜정,김세희,신호진,박윤희,박지영,김유진,신완식,김춘추 대한감염학회 2001 감염 Vol.33 No.4

Background : Pneumocytitis cainii pneumonia (PCP) can occur in immunocompromised hosts especially such as AIDS or cancer patients. Although recent research had focused on PCP in AIDS patients, few studies have described the clinical presentations of PCP in recipients of stem cell transplantation (SCT). We evaluated the clinical manifestations of PCP in SCT patients admitted at St. Mary's hospital, Seoul, Korea. Methods : The medical records of 17 PCP patients undergoing SCT between Feb. 1998 and Feb. 2000 were reviewed. The diagnosis of PCP was confirmed through the demonstration of Pneumocytitis cainii via either cytology of brochoalveolar lavage (BAL) or histological technique of lung biopsy. CMV disease and CMV infection were confirmed by BAL culture and antigenemia respectively . Results : Seventeen patients were all recipients of allogeneic SCT and 7 of 17 patients were performed non-sibling SCT. Patients presented with symptoms including brief period (4 ∼23 days) of fever (76%), dyspnea (70%), cough (64%), and signs such as rare(58.8%), Sixteen patients (94%) had been receiving immunosuppressive agent such as cyclosporine A (64%) or Fk506 (35%) without PCP prophylaxis. Eleven patients (64%) were treated with corticosteroid with mean dose of 16 mg/day prednisolone and mean duration of 4.6 months after post-SCT period. Twelve patients were co-infected with CMV. Another co-infected miCroorganisms were Pseudomonas aeruginosa, Mycobacterium tuberculosis, herpes simplex virus, parainfluenza virus, Average duration of treatment with trimethoprim-sulfamethoxazole (TMP/SMX) was 21 ±9 days. Four patients died, and three of them were related with PCP. Conclusion : PCP developed frequently in patients who were taking immunosuppressive drug due to graft versus host disease or were not taking TMP/SMX prophylaxis. High risk patients showing fever, cough, or dyspnea should be considered to take early bronchoscopic intervention for detection of PCP. When treat for PCP, it also be considered to the possibility of coinfection such as CMV. (Korean J Infect Dis 33:273∼279, 2001)

D-Amphetamine이 니코틴성 흥분작용에 의한 카테콜아민 분비작용에 미치는 영향

임건한,서유석,민선영,임지연,김용직,나광문,임동윤 朝鮮大學校 附設 醫學硏究所 2005 The Medical Journal of Chosun University Vol.30 No.1

본 연구의 목적은 d-arphetamine이 흰쥐의 적출부신 관류모델에서 니코틴 수용체 흥분에 의한 카테콜아민(CA) 유리작용에 미치는 영향을 검색하여 그 작용기전을 규명하고자 하였다. D-amphetamine은 흰쥐 부신정맥내로 60분간 관류시 d-amphetamine자체는 약한 CA 분비작용을 나타내었으나, d-amphetamine (30 μM)을 비롯한 강력한 neuronal nicotine 수용체 작용제인 cytisine (50 μM) 및 epibatidine (30 μM)에 의한 CA 유리작용을 처음 4-10분 동안만 유의하게 증강시켰다. 또한, d-amphetamine (30 μM)은 60분간 부신정맥 내로 관류한 상태에서 dihydropyridine L-형 칼슘통로 개방약물인 Bay-K-8644 (10 μM)과 세포질내 칼슘저장고에서 Ca^(2+) ATPase 억제제인 cyclopiazonic acid (10 μM)의 CA 유리작용을 처음 4분간만 유의하게 증강시켰다. 그러나, 고농도의 d-amphetamine (500 μM)은 상기한 모든 분비촉진제의 CA분비작용을 오히려 억제하였다. 이와 같은 연구결과로 보면, 흰쥐 관류 부신수질에서 d-amphetamine은 낮은 농도에서는 콜린성 니코틴 수용체 흥분에 의한 카테콜아민 분비반응을 증강시키지만, 고농도에서는 오히려 억제적으로 작용함을 시사한다. 따라서, d-amphetamine은 용량에 따라서 흰쥐 적출 관류부신수질의 니코틴 수용체의 작용제 및 길항제로 이중 작용(dual action)을 나타내는 것으로 생각된다. 이러한 d-amphetamine의 작용은 흰쥐 부신수질 크롬친화세포의 dihydropyridine계 L-형 칼슘통로의 활성화 및 세포 내 칼슘저장고로부터 칼슘유리작용과 관련성이 있는 것으로 사료된다. The purpose of the present study was to examine the effect of d-amphetamine on CA release evoked by nocotinic receptor stimulation from the isolated perfused model of the rat adrenal gland, and to establish its mechanism of action. D-amphetamine(30 μM), when perfused into an adrenal vein of the rat adrenal gland for 60 min, enhanced the CA secretory responses evoked by ACh (5.32 mM), nicotine (30 μM), cytisine (50 μM, a selective neuronal nicotinic Nn-receptor agonist) and epibatidine (30 nM, a selective neuronal nicotinic Nn receptor agonist) only for the first period (4~10 min), although it alone has weak effect on CA secretion. Moreover, d-amphetamine (30 μM) in to an adrenal vein for 60 min also augmented the CA release evoked by BAY-K-8644, an activator of the dihydropyridine L-type Ca^(2+) channels, and cyclopiazonic acid, an inhibitor of cytoplasmic Ca^(2+) ATPase only for the first peroid (4 min). However, in the presence rather inhibited the CA secretory responses evoked by the above all of secretagogues. Taken together, these experimental results suggest that d-amphetamine at a low concentration enhances the CA secretion from the rat adrenal medulla evoked by stimulation of cholinergic nicotininc receptors, but at a high concentration it rather inhibits them. It semms that d-amphetamine has dual action acting as both agonist and antagonist at nicotinic receptors of the isolated perfused rat adrenal medulla, which are might be dependent on the concentration. It is also thought that these actions of d-amphetamine are probably relevant to the activation of the dihydropyridine L-type Ca^(2+) channels located on the rat adrenomedullary chromaffin cell membrane and release of Ca^(2+) from the cytoplasmic store.

토양 미생물인 Streptomyces tubercidicus에서 분리한 GTPcyclohydrolase Ⅰ 저해제

한지만,김시욱,이인화,박열,정혜광,윤성명,유진철 조선대학교 약학연구소 1998 藥學硏究誌 Vol.19 No.1

GTP cyclohydrolase I (EC 3.5.4.16) catalyzes the conversion of GTP to D-erythro-7,8-dihydroneopterin triphosphates and formic acid. and thus performs the first committing step in the biosynthesis of the pteridine moiety of folk acid in microorganisms and of tetrahydrobiopterin in higher animals. GTP cyclohydrolase I isolated from Streptomyces tubercidicus was inhibited by DL-6-methyl-5,6,7,8-tetrahydropterin and xanthopterin, and was not inhibited by tetrahydrofolic acid, pterin, pterin-6-carboxylic acid, biopterin, neopterin, ribofravin. These results suggest that bacterial GTP cyclohydrolase I may be regulated by its metaboilic end product.