• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.321-324
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• 2001

Two recombinant Escherichia coli strains, GCSC6576 harboring a plasmid pSYL107 containing the Ralstonia eutropha polyhyclroxyalkanoate (PHA) biosynthesis genes and a fadR atoC mutant LS5218 harboring a plasmid pJC4 containing the Alcaligenes latus PHA biosynthesis genes were compared for their ability to synthesize poly(3-hydroxybutyrate-co-3-hydroxyvalerate) [P(3HB-co-3HV)] from whey as the sale carbon source. With the pH-stat fed-batch culture of E. coli LS5218, 、 ,ve obtained a cell concentration, a P(3HB-co-3HV) concentration. a P(3HB-co-3HV) content, and a 3HV fraction of 31.8 g/L, 10.6 g/L, 33.4 wt%. and 6.26 mol%, respectively at 39 h.

• Culinary science and hospitality research
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• v.14 no.4
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• pp.55-66
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• 2008

This study investigated the rheological and sensory characteristics of pickle with frozen pine mushroom. P3(Developed pickle seasoning) was the best by preference among three kinds of pine mushroom pickle seasoning. For flavor and functionality, pine mushroom pickle was processed by using three kinds of method(P3-1: P3+cinnamon 10 g, P3-2: P3+licorice 10 g and P3-3: P3+licorice 5 g+cinnamon 5 g). As a result, the product from P3-3(P3+licorice 5 g+cinnamon 5 g) was the best preferred pine mushroom pickle. The pH value of P3-3 was 2.15, 42.9 degrees Brix, and its color value was L(54.65), a(-1.61), b(17.87). Its texture level was higher than that of other products, but it would be lowered on storage. Until the 28th day of storage, microorganisms in pine mushroom pickle seasoning were detected less than 30 CFU/mL.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.2
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• pp.175-181
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• 2013

This study investigated the ability of extracts from Lentinus edodes (LE) and rice with Lentinus edodes mycelium (LEM) to inhibit diabetes and obesity. Lipid accumulation significantly decreased by 78% and 74% upon treatment with 300 ${\mu}g/mL$ of LE and LEM, respectively (p<0.01). Cholesteryl ester transfer protein (CETP) inhibition activity increased by 94% and 99% upon treatment with 300 ${\mu}g/mL$ of LE and LEM, respectively. In order to investigate the effect of LE and LEM on diabetes, the inhibition of protein tyrosine phosphate 1B (PTP1B) activity from the LE and LEM extracts at various concentrations (1, 3, 10, 30, 100, 300 ${\mu}g/mL$) was assessed. PTP1B activity by treatment with 10, 30, and 100 ${\mu}g/mL$ of LE, was inhibited at a rate of 7, 9, and 7% respectively. Also, PTP1B activity from treatment with increasing concentration of LEM led to a significant concentration-dependent inhibition of PTP1B activity (p<0.01). LE and LEM were orally administered for 28 days after a high fat diet (HFD). LE and LEM significantly reduced triglyceride, cholesterol, HDL-cholesterol and LDL-cholesterol levels. GOT and GPT were not significantly effected. These results indicate that extracts of LE and rice with LEM have potent activities useful in the treatment of obesity and diabetes mellitus.

• KSBB Journal
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• v.22 no.5
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• pp.345-350
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• 2007

Phosphosugars are found in all living organisms and are commercially valuable compounds with possible applications in the development of a wide range of specialty chemicals and medicines. In carbohydrate metabolism, fructose 6-phosphate (F6P) is an essential intermediate formed by phosphorylation of 6' position of fructose in glycolysis, gluconeogenesis, pentose phosphate pathway and Calvin cycle. In glycolysis, F6P lies within the glycolysis metabolic pathway and is produced by isomerisation of glucose 6-phosphate. For large-scale production, F6P could be produced from starch using many enzymes such as pullulanase, starch phosphorylase, isomerase and mutase. In enzymatic reactions carried out at high temperatures, the solubility of starch is increased and microbial contamination is minimized. Thus, thermophile-derived enzymes are preferred over mesophile-derived enzymes for industrial applications using starch. Recently, we reported the production of glucose 1-phosphate (G1P) from starch by Thermus caldophilus GK24 enzymes. Here we report the production of F6P from starch through three steps; from starch to glucose 1-phosphate (glucan phosphorylase, GP), then glucose 6-phosphate (phosphoglucomutase, GM) and then F6P (phosphoglucoisomerase, GI). Using 200 L of 1.2% soluble starch solution in potassium phosphate buffer, 1,253 g of G1P were produced. Then, 30% yields of F6P were attained at the optimum reaction conditions of GM : G1 (1 : 2.3), 63.5$^{\circ}C$, and pH 6.85. The optimum conditions were found by response surface methodology and the theoretical values were confirmed by the experiments. The optimum starch concentrations were 20 g/L under the given conditions.

• Korean Chemical Engineering Research
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• v.53 no.4
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• pp.524-529
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• 2015

This study was conducted to optimize the medium composition for cold-adaptive protease production of Enterobacteriaceae sp. by response surface methodology (RSM). Yeast extract, and TritonX-100 were identified as the significant factors affecting protease from one-factor-at-a-time method. RSM studies for optimizing protease production of Enterobacteriaceae sp. have been carried out for three parameters including yeast extract concentration, TritonX-100 concentration, and culture pH. These significant factors were optimized as 6.690 g/L yeast extract, 0.018 g/L Triton$^{TM}$ X-10, and pH 6.677. The experimentally obtained protease activity was 8.03 U /L, and it became 1.5-fold increase before optimization.

• Journal of Nutrition and Health
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• v.29 no.1
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• pp.59-69
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• 1996

Effects of dietary calcium(Ca), protein, and phosphorus(P) intake on bone mineral density (BMD) were investigated in 129 Korean premenopausal women(age 31-54 years) without diagnosed disease. BMD was measured at the spine(vertebrae L2-4) and femur(neck, Ward's triangle and trochanter). By stepwise multiple regression analysis it was shown that protein, Ca, and P intakes affected most significantly on BMD at the vertebrae L2-4, protein and P intakes affected most significantly on BMD at the femoral neck and Ward's triangle, and body mass index(BMI) affected most significantly on BMD at the trochanteric region. When ate-matched BMD % at the vertebrae L2-4 and all femoral sites was grouped by three levels(<90%, 90-99%, >=100%), only at the vertebrae L2-4>=100% and 90-99% groups had higher Ca intakes than <90% groups. When Ca, protein and P intakes of the recommended level for Korean(RDA) were grouped by three levels (Ca or P ; <=650mg/d, 650-750mg/d, >=750mg/d, Protein ; <=55g/d, 55-60g/d, >=65g/d), only at the vertebrae L2-4>55g/d of protein intake had higher age-matched BMD % than <=55g/d intake, >=750mg/d of Ca and P intakes, age-matched BMD % than <=650mg/d. In RDA range of Ca, protein, and P intakes, age-matched BMD % of the vertebrae L2-4 and all femoral sites was greater than 90%. Correlation between Ca intake and vertebral BMD was examined closer. There was more significant linear correlation between vertebral BMD and Ca intake below 800mg/d(r=0.346, p<0.0001)than above(r=0.376, p<0.019), implying a threshold effect and vertebral BMD was better expressed as a function of the logarithm of calcium intake(r=0.3881, p<0.0001). These results suggest that Ca, protein, and P intakes greater than RDA help to maintain proper BMD in middle-aged prementopausal women. Especially dietary Ca have important role in increasing the vertebral BMD and 800mg/d of Ca intake is optimum amount.

• KSBB Journal
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• v.8 no.5
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• pp.452-456
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• 1993

This study was carried out to optimize the fermentation conditions for direct alcohol fermentation of xylose by Pichia stipitis CBS 5776. The best cell growth and the ethanol production were obtained under 0.05 VVM aeration and 300rpm agitation at $30^{\circ}C$ using 100 g/l xylose medium of the initial pH 5.0. In the above condition, the maximum specific growth rate and maximum cell concentration were 0.14hr-1 and $1.3 \times109$ cells/ml, respectively. Pichia stipitis CBS 5776 also produced 40.2g/l ethanol utilizing about 96% of 100g/l xylose after 72hr fermentation. At this point, the overall volumetric ethanol productivity was 0.56g/1-hr and the ethanol yield was 0.42 g-ethanol/g-xylose consumed, which corresponds to 82% of the theoretical yield.

• Applied Biological Chemistry
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• v.39 no.3
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• pp.172-176
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• 1996

Effect of culture conditions such as pH, temperature, agitation speed and oxygen transfer rate on xylitol production from xylose by Candide parapsilosis ATCC 21019 mutant was investigated in a jar fermentor. The initial concentration of xylosr was fixed at 50 g/l in this experiment. When pH was increased, cell growth and xylose consumption rate were increased, but maximum xylitol production was shown in the range of pH 4.5 and 5.5 with a yield of 0.68 g/g-xylose. The optimal temperature for xylitol production was determined to be $30^{\circ}C$. Considering the importance of dissolved oxygen tension, for xylitol production, the effect of oxygen transfer rate coefficient $(k_La)$ on fermentation parameters was carefully evaluated in the range of $20{\sim}85\;hr{-1}\;of\;k_La$ (corresponding to $100{\sim}300$rpm of agitation speed). The xylitol production was maximized at $30\;hr^{-1}\;of\;k_La$(150 rpm). A higher oxygen transfer rate supported better cell growth with lower xylitol yield. It was determined that maximum xylitol concentration, xylitol yield and productivity was 35.8 g/l, 71.6% and $0.58\;g/l{\sim}hr^{-1}$, respectively, at $30\;hr^{-1}\;of\;k_La$ In order to further increase xylitol productivity, ferementation using the concentrated biomass(20 g/l) was carried out at the conditions of pH 4.5, $30^{\circ}C$ and $30\;hr\;1$ of oxygen transfer rate. The final xylitol concentration of 40 g/l was obtained at 18 hours of culture time. From this result, it was calculated that xylitol yield was 80ft on the basis of xylose consumption and volumetric productivity was $2.22\;g/l{\sim}hr$ which was increased by $3{\sim}4$ fold compared with $0.5{\sim}0.7\;g/l-hr$ obtained in a normal fermentation condition.

• Journal of The Korean Society of Agricultural Engineers
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• v.54 no.6
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• pp.143-150
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• 2012

바이오에탄올 생산공정은 당 (Sugar)을 기반으로 하는 공정과 합성가스를 이용하는 공정으로 분류할 수 있다. 이 가운데 합성가스를 이용하는 공정은 촉매를 이용한 화학적 공정과 혐기성 발효에 의한 생물학적 공정의 두 가지로 나뉜다. Clostridium ljungdahlii는 일산화탄소와 수소가 주요 성분으로 구성되는 합성가스를 이용하여 에탄올과 아세트산을 생산할 수 있는 균주 중의 하나로 알려져 있다. 합성가스 발효공정에서 pH는 미생물의 증식과 에탄올 등의 생산에 아주 중요한 요인 중의 하나이다. 본 연구에서는 pH 조건이 미생물의 생장과 에탄올 생산성에 미치는 영향을 조사하였다. C. ljungdahlii 배양은 엄격한 혐기성 조건에서 100 ml의 serum bottle과 pH 제어가 가능한 반응기를 이용한 실험결과, 회분식 배양 조건에서는 미생물의 생장과 에탄올 생산을 위한 최적 초기 pH는 7.0로 나타났다. 미생물 농도는 0.57 g/L, 에탄올 농도 0.91 g/L로 나타났다. pH 4.5 이하에서는 미생물의 생장이 멈추는 것으로 나타났다. pH 제어가 가능한 생물반응기에서는 pH 6.0 일때 에탄올 생산량이 pH 7.0 일때 보다 높게 나타났다. 일정 수준의 미생물 농도를 유지한 조건에서 합성가스를 기포식으로 주입하고 pH 5.9에서 5.4까지 제어하였을 때 미생물량과 에탄올 농도가 증가하였다. 60 시간이 지난 후에 미생물의 농도는 0.498 g/L, 에탄올은 1.056 g/L까지 이르렀다.

• Microbiology and Biotechnology Letters
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• v.45 no.3
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• pp.236-242
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• 2017

The conversion of marine biomass to renewable energy has been considered an alternative to fossil fuels. Butanol, in particular, can be used directly as a fuel. In this experiment, the brown alga Undaria pinnatifida was selected as a biomass for biobutanol production. Hyper thermal (HT) acid hydrolysis was used as an acid hydrolysis method to produce monosaccharides. The optimal pretreatment conditions for U. pinnatifida were determined as slurry with 10% (w/v) U. pinnatifida content and 270 mM $H_2SO_4$, and heating at $160^{\circ}C$ for 7.5 min. Enzymatic saccharification was carried out with Celluclast 1.5 L, Viscozyme L, and Ultraflo Max. The optimal saccharification condition was 12 U/ml Viscozyme L. Fermentations were carried out for the production of acetone, butanol, and ethanol by Clostridium acetobutylicum KCTC 1724, Clostridium beijerinckii KCTC 1785, and Clostridium tyrobutyricum KCTC 5387. The fermentations were carried out using a pH-control. The optimal ABE fermentation condition determined using C. acetobutylicum KCTC 1724 adapted to 160 g/l mannitol. An ABE concentration of 9.05 g/l (0.99 g/l acetone, 5.62 g/l butanol, 2.44 g/l ethanol) was obtained by the consumption of 24.14 g/l monosaccharide with $Y_{ABE}$ of 0.37 in pH 5.0.