카드뮴이 카드뮴 내성 효모세포내의 효소 활성에 미치는 영향

유대식,박은규,박정문 한국미생물생명공학회 ( 구 한국산업미생물학회 ) 1996 한국미생물·생명공학회지 Vol.24 No.3

카드뮴에 의하여 고도 카드뮴 내성 효모인 Hansenula anomala B-7 세포내 효소생성의 변화를 관찰하여 대사계의 변화를 추정했다. 1.0mM 카드뮴에 의하여 공시균의 alcohol dehydrogenase의 생성은 무첨가에 비하여 90% 이상 감소하나 malate dehydrogenase의 생성은 440% 증가되어, 카드뮴에 의하여 혐기적 대사계는 억제되고 호기적 대사계인 TCA 회로는 활성화되었다. 그리고 1.0 mM 카드뮴에 의하여 공시균의 해당계 효소인 phosphofructokinase의 생성은 약 40% 감소되었으나, 당의 호기적 분해대사계 효소인 6-phosphogluconate dehydrogenase의 생성은 약 136% 증가되어, 카드뮴에 의하여 EMP 대사계는 활성화되었다. 더욱이 1.0 mM 카드뮴에 의하여 공시균의 cytochrome c oxidase와 alkaline phosphatase의 생성의 각각 260%와 155% 증가되었다. 이상의 결과를 종합하면 카드뮴에 의하여 혐기적 대사계는 억제되나, 호기적 대사계는 활성화되며, 이로 인하여 생성된 다량의 NADH와 NADPH의 산화를 위하여 cytochrome c oxidase의 활성화는 필연적으로 요구되었다. 그리고 pyrimidine nucleotide 분해대사계 효소인 cytidine deaminase의 생성은 1.0mM 카드뮴에 의하여 약 86% 감소되어, 카드뮴은 necleotide 분해를 억제한다고 추측할 수 있었다. An extremely cadmium tolerant yeast, Hansenula anomala B-7 used to determine the modification of the intracellular enzyme activities by cadmium ion. The activities of alcohol dehydrogenase, phosphofructokinase, and cytidine deaminase were decreased up to 90%, 40%, and 86% compared with the control by mM cadmium nitrate respectively, but the activites of malate dehydrogenase, 6-phosphogluconate dehydrogenase, cytochrome c oxidase, and alkaline phosphatase were increased up to 440%, 136%, 260% and 155% compared with the control by 1 mM cadmium nitrate respectively. These show that the activities of the enzymes participating in Emboden-Mayerhof pathway (e.g. anaerobic metabolism) were reduced by cadmium, but those involved in hexose monophosphate pathway and tricarboxylic acid cycle (e.g. aerobic metabolism) were stimulated in contrast. It has been suggested that the diminished activity of cytideine deaminase in pyrimidine nucleotide dissimilation occured due to the inhibited nucleotide dissimilation by cadmium ion; the enhanced activity of cytochrome c oxidase was specifically required in order to oxidize a raised amount of NADH and NADPH due to the increased aerobic metabolism.

液體麴製造에 關한 硏究 : 異種菌株의 混合培養時 麴菌 移植方法에 關하여 Studies on inoculating method, cultivating different organisms of Aspergillus genus in the same medium

鄭基澤,兪大植 慶北大學校 1968 論文集 Vol.12 No.-

Cadmium에 대한 Metallothionein 및 Free Radical Scavenger에 관한 최근의 연구 동향

김영숙,유대식 동아시아식생활학회 2001 동아시아식생활학회지 Vol.11 No.1

Since the Industrial Revolution, people have enjoyed an abundant life, owing to the technological innovations of science. However, because of changes in the environment or polution to the environment, it has brought on many chronic diseases. Especially, even though it may be a small amount, if cadmium gets into a human body, because its biological half life is long, it fatally causes a kidney disease and damage to human organisms. It was reported that Metallothioneins(MT), a substance that is closely related with a free radical that comes from environmental pollution and the course of which cadmium, which causes chronic addiction in the body, is formed, along with harmful metals, make the toxicity reduce. MT compound led into the body by cadmium indirectly functions as an antioxidation, supplied adequate amount of vitamin E. and suppresses the accumulation of cadmium in heart, liver and blood. Cadmium content found in Korean soil according to the test conducted from 1992 to 1996 was 0.02~0,03㎎/㎏ in cereals, pulses, and potatoes. Free radical scavenger, finding solution for metal substance that comes from environmental pollution from food and natural substances implicates a better future for the study of food science.

발포성 사과주 제조에 관한 연구

정기택,유대식 경북대학교 1971 生産技術 Vol.5 No.-

We experimented about the selection of strains, adding sugar and materials for increasing a foam-retention, as a basis study to brew a sparkling apple wine. The results are such as following. a) B-1 strain was selected and fixed as a suitable yeast to a fermentation in low temperature. b) B-1 strain had a fermentation form that was very slowly at first time and was very fast as the time goes. c) The concentration of optimum alcohol was 12%, also 6% is possible. d) Sucrose was better than glucose as adding sugar for the after fermentation, and its adding quantity was 4% and good. e) Malt extract solution was considered to be most effective as an increasing materials for a foam-retention, and its adding quautity was 50% best and 20% good.

A New Species of Hyphomycetes, Aspergillus coreanus sp. nov., Isolated from Traditional Korean Nuruk

YU, TAE SHICK,YEO, SOO-HWAN,KIM, HYUN SOO 한국미생물 · 생명공학회 2004 Journal of microbiology and biotechnology Vol.14 No.1

Strain NR 1 5-1^(T) isolated from traditional Korean Nuruk is described as a new species and named as Aspergillus coreanus NR 15-1^(T) sp. nov. Strain NR 15-1^(T) grew rapidly to form yellow-green colonies whose surfaces were velvety on Czapek solution agar. Conidial heads were yellow to light and elliptical, whereas the conidiophore was colorless and typically long. In addition, vesicles were from flask-shaped to globose, and sterigmata are uniseriate. Conidia were spherical and deep yellow-green, and their surfaces were lightly roughened. The G+C content of strain NR 15-1' was 51 mol% and strain NR 15-1^(T) contained a dihydrogenated ubiquinone with Q9 (94.9%) as a major quinone. The nucleotide sequences of strain NR 15-l^(T) in the two Internal Transcribed Spacers (ITS 1 and 2) and 5.8s rDNA showed highest similarity when compared with that of A. tubingensis and A. phoenicis NRRL 365. However, based on morphological and chemotaxonomic characteristics, this strain was different from A. tubingensis and A. phoenicis NRRL 365'. On the basis of the data presented, it is proposed that strain NR 15-l^(T) should be placed in the genus Aspergillus as a new species, Aspergillus coreanus sp. nov. Therefore, the type strain of the new species is strain NR 15-1^(T)(=KCTC 18075P^(T), =KCCM 80006^(T)).

Nutritional and Cultural Characteristics of Cytosine Deaminase from Pseudomonas auerofaciens

Yu Tae-Shick 啓明大學校 生活科學硏究所 1976 科學論集 Vol.3 No.-

Effect of Titanium-Ion on the Growth of Various Bacterial Species

Tae Shick Yu 한국미생물학회 2004 The journal of microbiology Vol.42 No.1

There are a number of studies that explain the metabolism and roles of metallic titanium and titaniumion. One of the most intriguing results from these studies is the finding of metallic titanium having no bacteriostatic effects on oral bacterial species. In this research, the effects of titanium-ion on the growth of twenty-two bacterial species, some of which are commonly found in foods such as yoghurt, kimchi, and soy fermented products, were investigated. All but two bacteria, Escherichia coli and Pseudomonas aeruginosa appeared to be sensitive to titanium-ion. These two species were grown on 360 μg/ml of titanium-ions, and they were found to be resistant to the titanium-ion. Both the wild-type and plasmid- cured E. coli showed good growth in a medium with 200 μg/ml of titanium-ions. These results suggest that titanium-resistance was independent from the effects of the plasmid in E. coli.

Chemical Modification of Intracellular Cytosine Deaminase from Chromobacterium violaceum YK 391

Tae Shick Yu,김정,김대현 한국생물공학회 2005 Biotechnology and Bioprocess Engineering Vol.10 No.3

Cytosine deaminase (cytosine aminohydrolase, EC 3.5.4.1) stoichiometrically catalyzes the hydrolytic deamination of cytosine and 5-fluorocytosine to uracil and 5-fluorouracil, respectively. Amino acid residues located in or near the active sites of the intracellular cytosine deaminase from Chromobacterium violaceum YK 391 were identified by chemical modification studies. The enzymic activity was completely inhibited by chemical modifiers, such as 1 mM NBS, chloramine-T, -CMB, -HMB and iodine, and was strongly inhibited by 1 mM PMSF and pyridoxal 5'-phosphate. This chemical deactivation of the enzymic activity was reversed by a high concentration of cytosine. Furthermore, the deactivation of the enzymic activity by -CMB was also reversed by 1 mM cysteine-HCl, DTT and 2-mercaptoethanol. These results suggested that cysteine, tryptophan and methionine residues might be located in or near the active sites of the enzyme, while serine and lysine were indirectly involved in the enzymic activity. The intracellular cytosine deaminase from C. violaceum YK 391 was assumed to be a thiol enzyme.

중금속내성균주의 배양조건 및 균체내 축적

Yu, Tae-Shick,Song, Hyung-Ik 한국미생물 · 생명공학회 1981 한국미생물·생명공학회지 Vol.9 No.2

The cultural conditions and the intra cellular accumulation of cadmium was studied using a cadmium tolerant yeast strain B-7 which had been isolated from activated sludge collected from a zinc mining area. The organism was able to grow in a medium containing 3,000 $\mu\textrm{g}$/$m\ell$ of cadmium-ion. (C $d^{++}$) Optimum conditions for the growth of the organisms were 20~22$^{\circ}C$ and pH 5.0~8.0 under aerobic condition. The maximum cadmium accumulation was observed when the organism was grown at pH 6.0. The growth of B-7 was not affected by the addition of a silicone-based antifoamer, which stimulated the intra cellular accumulation of cadmium. The intra cellular cadmium accumulation started after the cell ceased to grow. One gram of cells accumulated 34.17mg of cadmium when the organism was grown in a medium containing 500 $\mu\textrm{g}$/$m\ell$ of cadmium and 0.2%, v/v silicone-based antifoamer at 28$^{\circ}C$ for 48 hours with shaking. About 73 % of the accumulated heavy metal by the organism was found in the cytoplasm.m. 카드뮴에 오염될 가능성이 있는 아연 광산지역의 오니로부터 중금속내성균을 분리한 고도카드뮴내성 효모인 B-7 배양조건 및 균체내 카드뮴의 축적에 대하여 검토했다. 효모 B-7은 3,000 $\mu\textrm{g}$/$m\ell$의 카드뮴 합유배지에서 생육이 가능하며 다른 연구자들의 카드뮴내성균보다 내성이 가장 큰 고도카드뮴내성균이었다. 이 효모는 22~22$^{\circ}C$및 pH 5.0~8.0의 조건에서 생육이 양호하였다. 카드뮴은 균체내 축적은 생육최적 pH인 6.0에서 가장 양호했으나, 그 이외의 pH에서는 급격히 저해되였으며 소포제 Silicon KM-70에 의하여 46.5%의 카드뮴 축적을 촉진시켰다. 카드뮴의 균체내 축적은 정지기 후반에 일어나며 0.2% Silicon과 50 $\mu\textrm{g}$/$m\ell$의 카드뮴을 함유하는 배지에서 28$^{\circ}C$, 48시간 진탕 배양한 바 건조균체 당(g) 34.17mg의 카드뮴을 축적시켰다. 축적 카드뮴의 73%가 세포질 중에 축적되었으며 나머지 27%의 카드뮴은 세포벽 및 핵과 같은 4,000$\times$g에서 침전되는 성분에 축적되었다.

Purification and Characteristics of Glucoamylase in Aspergillus oryzae NR 3-6 Isolated from Traditional Korean Nuruk

Yu, Tae-Shick,Kim, Tae-Hyoung,Joo, Chong-Yoon The Microbiological Society of Korea 1999 The journal of microbiology Vol.37 No.2

The purification system of glucoamylase (glucan 1,4-${\alpha}$-glucosidase, EC 3. 2. 1. 3), some characteristics of the purified enzyme and hydrolysis rate of various raw starch were investigated through several experiments. The enzyme was produced on a solid, uncooked wheat bran medium of Aspergillus oryzae NR 3-6 isolated from traditional Korean Nuruk. The enzyme was homogeneously purified 6.8-fold with an overall yield of 28.3% by the criteria of disc- and SDS-polyacrylamide gel electrophoresis. The molecular weight was estimated to be 48 kDa by SDS-PAGE. The optimum temperature and pH were 55$^{\circ}C$ and 4.0, respectively. The enzyme was stable at a pH range of 3.0∼10.0 and below 45$^{\circ}C$. Enzyme activity was inhibited about 27% by 1mM Hg2+. The hydrolysis rate of raw wheat starch was shown to be 17.5-fold faster than the hydrolysis rate of soluble starch. The purified enzyme was identified as glucoamylase because the product of soluble starch by the purified enzyme was mainly glucose by thin layer chromatography.