• 한국미생물·생명공학회지
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• 제13권4호
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• pp.397-402
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• 1985

C. thermosaccharolyticum을 이용하여 xylose, glucose, cellobiose등을 각각 단일기질 및 혼합기질로 배양한 결과는 다음과 같다. 기질의 종류에 관계없이 에탄올의 생산양상은 Leudeking-Piret모델에 따랐으며 q$_{p}$=$\alpha$ $\mu$＋$\beta$의 식으로 나타낼 수 있었다. 단일당에서의 배양결과 glucose, xylose, cellobiose 각 당에서의 비증식속도는 0.363 h$^{-1}$, 0.242 h$^{-1}$, 0.144 h$^{-1}$로 균의 증식은 glucose를 기질로 사용하였을 때가 가장 좋았다. 에탄올 생산성은 xylose에서 가장 좋았으며, 각 당에서의 에탄올수율은 0.38g ethanol/g xylose, 0.34 g ethanol/g cellobiose, 0.242g ethano1/g glucose 이었다. glucose에서의 배양결과, 배양 12시간이후 균의 자기소화현상이 현저히 일어났으며, 다른 당에서와는 달리 에탄올 생산양상은 $\alpha$값이 음수를 나타내므로써, 균의 생육이 증가하면 오히려 에탄을 비생산속도는 감소하는 경향을 보였다. 서로 다른 당을 혼합하여 기질로 사용할 경우, 각 당의 이용특성은 이들을 단독기질로 배양하였을 때의 소비양상과 유사하여 각 당은 서로 영향을 미치지 않고, 독립적으로 자화되는 것으로 생각된다. 혼합당에서의 기질소비는 glucose, xylose, cellobiose순으로 소비되었으며, 또한 에탄을 생산성은 glucose가 첨가된 경우 glucose 농도가 낮고(5g/l), glucose를 기질로 하여 균이 왕성하게 증식한 상태에서 xylose나 cellobiose를 이용하므로써 glucose만을 단독기질로 배양한 결과보다 좋았다.

• KSBB Journal
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• 제7권4호
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• pp.265-270
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• 1992

자연계에 널리 존재하는 저렴한 기질들은 대부분 여러 종류의 탄소원들을 함유한다. 이러한 혼합기질을 이용하는 효율적인 발효공정을 개발하기 위해서는 이들 기질들이 서로 어떻게 이용되는가를 알아야 하며, 사용되는 미생물의 생육과 생성물 생산을 잘 표현할 수 있는 동력학적 모델이 필요하다. P. stipitis에 의해 혼합기질에서 에탄오릉ㄹ 생산할 때 glucose는 xylose와 cellobiose 이용에 대해 ca-tabilite repression을 일으켰으며, 초기 glucose농도가 높을수록 xylose이용에서 균체의 생육속도는 감소하였으며 xylose이용시간도 길어졌다. 또한 glucose/xylose발효시 xylose이용에서 감소된 생육속도는 glucose가 xylose이용에 permenant repression을 야기시킨다는 것을 알 수 있었다. Cyclic AMP가 중개하는 catabolite repression mechanism에 기초하여 혼합기질에서 생육하는 P. stipitis의 생육모델을 발전시켰다 이 보텔식들을 이용하여 컴퓨터 simulation한 결과는 혼합기질로부터 P. stipitis에 의한 생육 및 에탄올 생성 실험결과와 비교적 잘 일치하였다.

• Journal of Microbiology and Biotechnology
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• 제24권12호
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• pp.1622-1628
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• 2014

DagA, a ${\beta}$-agarase, was produced by cultivating a recombinant Streptomyces lividans in a glucose medium or a mixed-sugar medium simulating microalgae hydrolysate. The optimum composition of the glucose medium was identified as 25 g/l glucose, 10 g/l yeast extract, and $5g/l\;MgCl_2{\cdot}6H_2O$. With this, a DagA activity of 7.26 U/ml could be obtained. When a mixed-sugar medium containing 25 g/l of sugars was used, a DagA activity of 4.81 U/ml was obtained with very low substrate utilization efficiency owing to the catabolic repression of glucose against the other sugars. When glucose and galactose were removed from the medium, an unexpectedly high DagA activity of about 8.7 U/ml was obtained, even though a smaller amount of sugars was used. It is recommended for better substrate utilization and process economics that glucose and galactose be eliminated from the medium, by being consumed by some other useful applications, before the production of DagA.

• Journal of Plant Biology
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• 제6권4호
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• pp.1-4
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• 1963

Using conidia of Neurospora, changes in respiratory activities and the sensitivity to the ultraviolet light of the cells at different growing stages were measured by manometric methods, and the correlation between them was observed. Efficiency in the utilization of various carbon sources, such as, glucose, sucrose, maltose, starch and sodium acetate, in growth and exogenous respiration of N. crassa was also determined. Growth rate of N. crassa was decreased considerably in the medium containing sodium acetate than in the glucose medium and was almost zero in the lactose medium, whereas the utilization of sucrose, maltose and starch was ve교 high, as that of glucose. Respiratory activities of the cells veried considerably depending upon their different growing stages. Actively growing hyphae exhibited the greatest activity in exogenous glucose respiration, followed by germinating and activated conidia in decreasing order. There was no proportional relationship between the dose of ultraviolet light irradiated and its effect on the respiratory activity of the cells, though the more the dose of ultraviolet light, the more the injury. The sensitivity of the cells to ultraviolet light varied with the different respiratory activities of the cells linked to the developmental stages. In general, the more actively growing cells having high respiratory activities exhibited the more serious injury.

• 한국미생물·생명공학회지
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• 제19권2호
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• pp.128-134
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• 1991

To study the reduced growth and synthesis, proeviously reported, of ${\beta}$-galactosidase of alkalophilic Bacillus sp. YS-309 at the higher lactose concentration of 0.5% (w/v) in the medium, lactose transport and utilization were examined. The results showed that lactose transport was influenced by the addition of four kinds of antibiotics, and tetracycline stimulated most but not valinomycin. PEP-potentials of the cells grown on lactose was estimated lower than the cells on glucose and on galactose. Thus, the transport of lactose was independent of intracellular PEP and phosphorylation reactions, and was thought to be uptaked directly or oxidized in part in the transport process. In the other hand, once lactose was uptaked into the cells, it was hydrolyzed by ${\beta}$-glactosidase to glucose and galactose. The former was metabolized fast but the latter was accumulated. Galactose and lactose were not utilized until glucose was mostly depleted in the medium. The ${\beta}$-galactosidase synthesis decreased in the presence of glucose over 0.2% and galactose over 0.05 to 0.1%, respectively. In conclusion, it was considered for glucose as a repressor and galactose as a inducer for ${\beta}$-galactosidase synthesis even though the mechanisms were not elucidated. Catabolite repression of glucose on the enzyme synthesis was not relieved by the addition of exogeneous cAMP.

• Diabetes and Metabolism Journal
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• 제42권6호
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• pp.465-471
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• 2018

My professional journey to understand the glucose homeostasis began in the 1990s, starting from cloning of the promoter region of glucose transporter type 2 (GLUT2) gene that led us to establish research foundation of my group. When I was a graduate student, I simply thought that hyperglycemia, a typical clinical manifestation of type 2 diabetes mellitus (T2DM), could be caused by a defect in the glucose transport system in the body. Thus, if a molecular mechanism controlling glucose transport system could be understood, treatment of T2DM could be possible. In the early 70s, hyperglycemia was thought to develop primarily due to a defect in the muscle and adipose tissue; thus, muscle/adipose tissue type glucose transporter (GLUT4) became a major research interest in the diabetology. However, glucose utilization occurs not only in muscle/adipose tissue but also in liver and brain. Thus, I was interested in the hepatic glucose transport system, where glucose storage and release are the most actively occurring.

• Journal of Microbiology and Biotechnology
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• 제30권12호
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• pp.1944-1949
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• 2020

Mutant sugar transporter ScGAL2-N376F was overexpressed in Kluyveromyces marxianus for efficient utilization of xylose, which is one of the main components of cellulosic biomass. K. marxianus ScGal2_N376F, the ScGAL2-N376F-overexpressing strain, exhibited 47.04 g/l of xylose consumption and 26.55 g/l of xylitol production, as compared to the parental strain (24.68 g/l and 7.03 g/l, respectively) when xylose was used as the sole carbon source. When a mixture of glucose and xylose was used as the carbon source, xylose consumption and xylitol production rates were improved by 195% and 360%, respectively, by K. marxianus ScGal2_N376F. Moreover, the glucose consumption rate was improved by 27% as compared to that in the parental strain. Overexpression of both wild-type ScGAL2 and mutant ScGAL2-N376F showed 48% and 52% enhanced sugar consumption and ethanol production rates, respectively, when a mixture of glucose and galactose was used as the carbon source, which is the main component of marine biomass. As shown in this study, ScGAL2-N376F overexpression can be applied for the efficient production of biofuels or biochemicals from cellulosic or marine biomass.

• 한국입자에어로졸학회지
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• 제10권2호
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• pp.53-59
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• 2014

Palladium (Pd) nanoparticles attached graphene (GR) composite was synthesized for an enhanced glucose biosensor. Aerosol spray pyrolysis (ASP) was employed to synthesize the GR-Pd composite using a colloidal mixture of graphene oxide (GO) and palladium chloride ($PdCl_2$) precursor. The effects of the weight ratio of the Pd/GR on the particle properties including the morphology and crystal structure were investigated. The morphology of GR-Pd composites was generally the shape of a crumpled paper ball, and the average composite size was about $1{\mu}m$. Pd nanoparticles less than 20 nm in diameter were deposited on GR sheets and the Pd nanoparticles showed clear crystallinity. The characteristic of the glucose biosensor fabricated with the as-prepared GR-Pd composite was tested through cyclic voltammetry measurements. The biosensor exhibited a high current flow as well as clear redox peaks, which resulted in a superior ability of the catalyst in terms of an electrochemical reaction. The highest sensitivity obtained from the amperometric response of the glucose biosensor was $14.4{\mu}A/mM{\cdot}cm^2$.

• Journal of Nutrition and Health
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• 제13권4호
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• pp.167-176
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• 1980

This study was conducted to compare effects of various types of dietary carboh ydrates fed with different levels of protein on the protein utilization in weanling rats. Sixty male Sprague-Dawley rats weighing $60{\pm}1.3grams$ were adapted for 1 week with 77% starch-15% casein diet. Then the animals divided into 12 groups according to body weight and fed each experimental diet for two weeks. Carbodydrates used were glucose, starch, and sucrose and the amount of protein given were 0g, 1g, 3g, 5g casein/day. Protein portion of the diet was fed in two seperate feedings per day while nonprotein portion was fed ad libitum. It seemed that there was no significant difference in the protein utilization by using the different kinds of carbohydrate, but in P.E.R., N.P.U., weights of organs and protein and lipid in total carcass, glucose groups were tended to be slightly lower than starch and sucrose groups. The larger the amount of casein given, the higher were the value of body weight gain, F.E.R., weights of organs, total lipid in carcass and the amount of nitrogen retention. On the while, the larger the amount of casein given, the lower were the value of the intake of non-protein portion, P.E.R., N.P.U, and the percentage of nitrogen retention.

• Journal of the Korean Data and Information Science Society
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• 제19권4호
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• pp.1091-1100
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• 2008

The purpose of this study is to find out how energy substrate's utilizations in the maximal exercise-cardiorespiratory function and the energy metabolic variation- have the effect on before and after the supplements of coenzyme Q10(100mg per day for 8 weeks) based on the male students(CoQ10=8, placebo=8) of high school. The results of this study are as follows: Maximal oxygen uptake and maximal oxygen per weight are found to have the significant increase respectively in supplement group. Glucose is found to have the significant decrease after the supplement of CoQ10. And then FFA is found to have the significant increase. In the above results, the supplements of CoQ10 and cardiorespiratory function in the maximal exercise are found to have the improvement. CoQ10 in the anaerobic exercise spares the energy's utilization of Glucose and then is found to have the increase of the utilization of FFA. CoQ10 in the aerobic exercise is reported to have the increase of the utilization of FFA and then CoQ10 in the maximal exercise is also recognized to have the increase of the utilization of FFA, or energy substrates.