Bacillus licheniformis KFB-C14가 생산하는 내열성 Chitinase의 정체 및 특성

홍범식,윤호근,신동훈,조홍연 한국미생물생명공학회 ( 구 한국산업미생물학회 ) 1996 한국미생물·생명공학회지 Vol.24 No.5

Bacillus licheniformis KFB-C14가 생산하는 내열성 chitinase를 30~70% ammonium sulfate fractionation, DEAE-Toyopearl 650M, Butyl-Toyopearl 650M, TSK-Gel Toyopearl HW-55F에 의해 정제도 66배, 수율 21%로 전기영동적으로 균일하게 정제하였다. 정제 단백질은 gel permeation chromatography에 의해 86,000±2,000의 분자량을 나타내었으며, SDS 전기영동에 의해 밝혀진 본 효소의 subunit 구조는 monomer였다. 효소 단백질의 안정성을 검토한 결과 80℃에서 30분 열처리에 의해 56%, 37℃에서 20분간 40% ethanol과 ethyl acetate, 단백질 변성제 등의 처리시에도 50% 이상의 잔존활성을 나타냄으로써 공업적으로 유용성이 높은 안정한 단백질로 판명되었다. 효소반응의 최적 pH와 온도는 pH 6.0과 60℃이었고 Mn^2+ 이온에 의해 효소 활성이 저해되었으나 EDTA, N-ethylmaleimide, p-chloromercuribenzoate 등에 의한 활성감소는 관찰되지 않음으로써 금속효소 또는 thiol계 효소에 속하지 않음을 알 수 있었다. 본 효소는 colloidal chitin, 시판용 chitin에는 반응성이 높았으나 exo형 chitinase의 대표적인 기질인 p-nitrophenyl-2-aectamido-2deoxy-β-glucopyranoside, NN'-diacetylchitobiose에는 전혀 반응성을 보이지 않는 전형적인 endo형의 chitinase였다. 본 효소는 colloidal chitin으로부터 주로 (GlcNAc)_2를, 반응시간 경과에 따라 (GlcNAc)_1과 (GlcNAc)_3을 생성하는 반응성을 보였다. Chitinase (EC 3.2.1.14) from culture fluid of Bacillus licheniformis KFB-C14 was purified 66-folds to homogenity in overall yield of 21% by ammonium sulfate fractionation, DEAE-Toyopearl, Butyl-Toyopearl and TSK-Gel HW-55F column chromatography. The enzyme protein had a molecular weight of about 86,000 and was composed of one subunit. The enzyme was significantly stable not only at high temperature but also on treatment with organic solvents and protein denaturants such as SDS, urea and guanidine·HCl. The optimum temperature and pH for reaction was 60℃ and 6.0,respectively. The enzyme activity was inhibited by only Mn^2+ ion, but not inhibited by EDTA, N-ethylmaleimide and pCMB. The enzyme had high activity with colloidal chitin (V_max: 421) and commercial chitin (V_max :480), but not with typical substrates of exo type chitinase. The thermostable chitinase had an useful reactivity for producing functional chitooligosaccharide, showing the production of (GlcNAc)_1, (GlcNAc)_3, and (GlcNAc)_2 as major product.

내열성 Chitinase 생산균주의 분리 및 효소생산 특성

홍범식,윤호근,신동훈,조홍연 한국미생물생명공학회 ( 구 한국산업미생물학회 ) 1996 한국미생물·생명공학회지 Vol.24 No.5

자연계 고온환경으로부터 내열성 chitinase 우수하고 반응산물로 N-acetyl-D-glucosamine 이량체(GlcNAc)_2를 생산하는 균주를 분리 선별하고 Bacillus licheniformis KFB-C14로 동정하였다. 선별균주의 효소생산 특성은 탄소원으로서 효소기질인 colloidal chitin이 첨가될 때만이 생합성이 유도되었으며 유도제의 첨가시기에 의해 효소생산이 크게 영향을 받았다. 각종 무기, 유기태 질소원 중 yeast extract가 활성과 비활성을 각각 약 2배 증가시켰으며 높은 친화도를 나타내었다. 균의 최대생육과 효소의 최대생산온도는 55℃이었다. 본 균주의 내열성 chitinase 생산에 미치는 최적배양조건은 1.2% colloidal chitin, 0.15% K_2HPO_4, 0.05% KH_2PO_4 0.01% MgSO_4·7H_2O, 0.1% yeast extract, pH 6.5의 배지를 55℃, 150rpm에서 40시간 회전진탕배양 하였을 때로 3.89 units/ml의 효소활성과 7.4 units/mg의 비활성을 나타내었다. A strain capable of producing thermostable chitinase suitable for chitooligosaccharide production was isolated from high temperature environment and identified as Bacillus licheniformis. The chitinase from Bacillus licheniformis KFB-C14 was only induced by addition of colloidal chitin into the basal medium as carbon source, showing the decrease of the chitinase production by supplemental addition of other carbon sources into the medium containing 1.0% colloidal chitin. Among organic and inorganic nitrogen sources, yeast extract was the most effective for the increase of total activity and specific activity, and had high affinity for the enzyme production. The optimum temperature of cell growth and thermostable chitinase production was 55℃. The optimum culture medium was composed of 1.2% colloidal chitin, 0.15% K_2HPO_4, 0.05% KH_2PO_4 0.01% MgSO_4·7H_2O, 0.1% yeast extract (pH 6.5). Bacillus licheniformis KFB-C14 produced the thermostable chitinase of 3.89 units per culture fluid and 7.4 units per mg protein under rotary shaking at 150 rpm for 40 hr.

栗谷의 倫理敎育思想

元弘淵 江陵大學統一問題硏究所 1984 統一問題硏究 Vol.1 No.-

Yul-gok(1536-1584) was one of the figures who were remarkable for philosophy, ethics, education and politics in the Yi dynasty of 16 century. He was a scholar who succeeded to human nature philosophy in Confucianism and made development of its scholastic theory. His basic thought in education and politics is sincerity. It is the way of Heaven in Nature. And it also means the good nature toward rightness in human mature as complex concept of reason, intelligence and conscience. Therefore the aim of his education lies in cultiviation of ethical education which made people exercise a good nature positively. Such an education is to develop a fine character. And besides, it aims at cultivating men of sincerity who contribute greatly to socialization of nation in such a way as to make it morerightous and ethical. So Yul-gok thinks that the aim of politics is to make people rich, that is, to give them good with sincerity. He says that he who is responsible for politics should have fine character and treat his people with sincerity as parents do their own children. So people in the folling generations ofter call him 'governing by philosophers' thinkers. To be short, the close examination of his thought for ethical education reveals that a man of fine character should be responsible for politics and that he denys governmental authority of the sovereign over the people who is short of sincerity even if he has a succession to the throne.

환자 만족도 조사를 통한 QI활동의 효과 평가 : 일개 병원을 중심으로

박연옥,김미숙,고은정,김연정,홍창호 한국의료QA학회 1998 한국의료질향상학회지 Vol.5 No.2

Background : Evaluation of patient's satisfaction is one of the most important aspects of quality improvement. If the patient highly satisfies with the medical service provided in the hospital, he/she will be likely to visit the same hospital again. Patient's satisfaction of a particular hospital is directly correlated with hospital profits as well as reputation in the community. For this reason, various kinds of survey measuring satisfaction level have been performed and many kind of QI activities for enhancing the profits as well as reputation in the community. For this reason, various kinds of survey measuring satisfaction level have been performed and many kind of QI activities for enhancing the patient's satisfaction. This study is to find the effect of hospital QI activities on the patient's satisfaction level. Methods : After questionnares were developed, survey of measuring satisfaction level was performed in August. 1998. On the basis of survey results. Ql activities were carried out to attain the target point of 4.0 and subsequent survey was done in November. 1998. Results : With three main principles of "problem solving approach with kindness". "helping patient to participate in medical procedure with sufficient information", and "putting employees into practice of attitude with human respect", the average level of satisfaction was enhanced from 3.45 to 3.55 level. Also kindness level of employees was increased from 3.71 to 3.82. Level of dissatisfaction about insufficient explanation and unkind attitude was dropped from 69% to 48% and from 82% to 46% respectively. Conclusion : With the result of this study overall satisfaction level was enhanced. In order to keep these advantages a operation of Quality Improvement Task Force Team in each subject will be required.

PFM方式 直列形 dc-dc Converter에 關한 硏究

鄭然澤,金洪喆 명지대학교 1976 明大論文集 Vol.9 No.-

This paper described the circuits of self-commutated dc-dc converter by the PFM method. The circuit is composed with a smoothing circuit and a thyristor triggered by a UJT relaxation oscillator. The result is that the output voltage of this device can be adjusted more stably by the pulse frequency of the oscillator than that of other methods.

분산시스템 구성에 관한 연구

이연식,박기홍 群山大學校自然科學硏究所 1987 自然科學硏究 Vol.2 No.-

Recently, distributed system has become the main issue in data processing system. And many researchers has supposed and presented the result of their studies. In this paper, we divided the function of distributed system into three parts-information processing, database processing and network processing. And, we supposed the configurations of each functions by analysis of their structures and characteristics.

완도납석과 TEOS로부터 β- Sialon 세라믹스의 제조

이홍림,손연하 연세대학교 산업기술연구소 1990 논문집 Vol.22 No.2

β-sialon powder was prepared from Wando pyrophyllite by the carbothermal reduction and nitridation at 1350℃ for 10h in N₂atmosphere. Si component which was derived from TEOS was added to Wando pyrophyllite in order to control Z value. Two kinds of method were applied for synthesis of β-sialon, one was to add amorphous silica, which was derived from TEOS, to Wando pyrophyllite and TEOS(process A), the other was started from the mixture of Wando pyrophyllite and TEOS(process B). 8 wt% Y ₂O ₃was added to the synthesized β-sialon powders as a sintering aid, and the mixed powders were hot-pressed at 1750℃ for 120 min in N₂atmosphere under 30MPa. The obtained maximum values of M.O.R., hardness and ?? were 667MPa, 16GPa and ??, respectively, and they are the values obtained from β-Sialon ceramics with 0.5 of Z value prepared by process A.

객체지향 데어터베이스 시스템에서 능동규칙 설계를 위한 메소드의 매개변수 이용

이연식,배석찬,홍석기 群山大學校 1996 論文集 Vol.23 No.-

The methods, class components of object- oriented database, regard as the chaining events that are able to access the states of object directly and invoke other methods. And, because these methods are composed of codes or procedures, it describe the rules which are used by means of the response of events in active database easily. In this paper, we propose and implement the method that designs the efficient methods of classes using various parameter passing mechanisms in active rule design. This proposed method describes the characteristics and activating region of rules precisely and manages those efficiently. And also, using this method, it can be easily understand the changes of semantics that occur on account of insertion or deletion of rules.

웨이브렛 신경회로망을 이용한 비선형 시스템의 안정한 직접 적응 제어

서재용,연정흠,원경재,서승진,전홍태 중앙대학교 생산공학연구소 1998 생산공학연구소 논문집 Vol.7 No.2

이 논문에서는 웨이브렛 신경회로망을 사용하여 알려지지 않은 비선형 시스템을 안정하게 적응 제어하는 문제를 다룬다. 비선형 시스템의 정확한 제어는 함수를 근사화하는 데 상용된 함수 근사화기의 정확성과 효율성에 의존한다. 이에 기준 함수의 선택이 자유롭고 함수 근사화 능력이 뛰어난 웨이브렛 신경회로망을 비선형 시스템 제어에 사용한다. 초기 웨이브렛 신경회로망 제어기를 설정하는 방법은 먼저 제어기 입력의 시-주파수 특성을 분석해서 웨이브렛 신경회로망 변수인 신축과 이동을 구하고, 다음에 Lyapunov 안정성 이론에 기초한 적응 법칙을 사용하여 연결 강도를 조절하는 것이다. 이 직접 적응 웨이브렛 신경회로망 제어기를 불안정한 비선형 시스템인 역 진자 시스템을 제어하는 데 적용한다. In this paper, we deal with the problem of controlling an unknown nonlinear dynamical system, using wavelet network. Accurate control of the nonlinear systems depends critically on the accuracy and efficiency of the function approximator used to approximate the function. Thus, we use wavelet network which shows high capability of approximating the functions and includes the free-selection of the basis functions for the control of the nonlinear system. The method of constructing an initial adaptive wavelet network controller is that we find the dilation and translation that are wavelet network parameters by analyzing the time-frequency characteristics of the controller's input, and then, the weight is adjusted by the adaptive law based on the Lyapunov stability theory. We apply this direct adaptive wavelet network controller to control the inverted pendulum system which is an unstable system.

Flavobacterium meningosepticum의 Nucleoside Oxidase와 Peroxidase 생산특성

최양문,조홍연,양한철 한국미생물생명공학회 ( 구 한국산업미생물학회 ) 1996 한국미생물·생명공학회지 Vol.24 No.6

Flavobacterium meningosepticum로부터 nucleoside oxidase와 peroxidase의 최대생산 조건을 검토한 결과 탄소원으로는 surcose, 질소원으로는 Polypepton이 좋았으며, Fe^2+, Fe^3+이나 또는 이들 이온과 함께 Cu^2+을 배지에 첨가시 두 효소의 생산량은 증가하였다. 또한 2'-deoxyguanosine, 2'-deoxyadenosine, N^6-methyladenosine 및 1-methyladenosine의 첨가는 두 효소의 생산을 증가시켰으며 특히 N^6-methyladenosine과 1-methyladenosine의 첨가는 생산된 균체량은 적었으나 두 효소생산량은 증가시켰다. 배지조건 및 배양시간에 따른 효소생산의 양상을 검토한 결과 두 효소는 거의 유사한 경향을 보였고 효소생산에 미치는 환경인자들 중 산소의 충분한 공급이 필수적이었다. 이상의 결과들로부터 세포내에서 nucleoside가 nucleoside oxidase에 의해 산화될 때 생성되는 H_2O_2를 peroxidase가 분해할 가능성이 시사되었다. Optimal cultural conditions were investigated for the maximal productivity of nucleoside oxidase and peroxidase from Flavobacterium meningosepticum. Sucrose and Polypepton were the best as a carbon source and a nitrogen source. Fe^2+, Fe^3+ and Cu^2+ increased the activities of the two enzymes and were essential in medium containing peptone as a nitrogen source. Nucleoside derivatives such as 2'-deoxyguanosine, 2'-deoxyadenosine, N^6-methyladenosine and 1-methyladenosine were effective for the production of the two enzymes. Especially, the addition of N^6-methyladenosine and 1-methyladenosine decreased cell growth, but increased the two enzyme activities. High level of oxygen also was essential factor for formation and/or induction of these enzymes. From the summary of this study about optimal medium and environmental conditions, nucleoside oxidase was biosynthesized in proportion to peroxidase. These results suggested that the role of peroxidase should be degradation of H_2O_2 generated by nucleoside oxidase in the cell of Flavobacterium meningosepticum.