• Title/Summary/Keyword: fermentation

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Pervaporation of Butanol from their Aqueous Solution using a PDMS-Zeolite Composite Membrane (PDMS-Zeolite 복합막을 이용한 부탄올 투과증발)

  • Kong, Chang-In;Cho, Moon-Hee;Lee, Yong-Taek
    • Korean Chemical Engineering Research
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    • v.49 no.6
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    • pp.816-822
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    • 2011
  • Pervaporation is known to be a low energy consumption process since it needs only an electric power to maintain the permeate side in vacuum. Also, the pervaporation is an environmentally clean technology because it does not use the third material such as an entrainer for either an azeotropic distillation or an extractive distillation. In this study, Silicalite-1 particles are hydrothermally synthesized and polydimethylsiloxane(PDMS)-zeolite composite membranes are prepared with a mixture of synthesized Silicalite-1 particles and PDMS-polymer. They are used to separate n-butanol from its aqueous solution. Pervaporation characteristics such as a permeation flux and a separation factor are investigated as a function of the feed concentration and the weight % of Silicalite-1 particles in the membrane. A 1,000 $cm^3$ aqueous solution containing butanol of low mole fraction such as order of 0.001 was used as a feed to the membrane cell while the pressure of the permeation side was kept about 0.2~0.3 torr. When the butanol concentration in the feed solution was 0.015 mole fraction, the flux of n-butanol significantly increased from 14.5 g/ $m^2$/hr to 186.3 g/$m^2$/hr as the Silicalite-1 content increased from 0 wt% to 10 wt%, indicating that the Silicalite-1 molecular sieve improved the membrane permselectivity from 4.8 to 11.8 due to its unique crystalline microporous structure and its strong hydrophobicity. Consequently, the concentration of n-butanol in the permeate substantially increased from 0.07 to 0.15 mole fraction. This composite membrane could be potentially appliable for separation of n-butanol from insitu fermentation broth where n-butanol is produced at a fairly low concentration of 0.015 mole fraction.

Production of Levulinic Acid from Gelidium amansii Using Two Step Acid Hydrolysis (우뭇가사리로부터 레불린산 생산공정을 위한 2단 산 가수분해)

  • Kim, Jun Seok
    • Korean Chemical Engineering Research
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    • v.51 no.4
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    • pp.438-442
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    • 2013
  • The study of bioproduct production from inexpensive biomass such as marine biomass has recently attracted considerable attention. Because, marine biomass which compared to land biomass, it can be grown rapidly and is easily cultivated without the need for expensive equipment. In addition, the carbohydrate contents are similar or higher than land biomass such as woody biomass and can be easily converted to chemicals through proper chemical processes. In the production of various biochemicals from marine biomass, levulinic acid is a highly versatile chemical with numerous industrial uses and has the potential to become a commodity chemical. It can be used as a raw material for resins, plasticizers, textiles, animal feed, coatings and antifreeze. In this study, experiments were carried out to determine the optimum conditions of temperature, acid concentration and reaction time for production of levulinic acid from marine biomass, Gelidium amansii, using two-step treatment. In the first hydrolysis step, solid-state cellulose which was used to produce ethanol by fermentation and liquid-state galactose which used to produce bioproduct such as levulinic aicd were obtained through acid soaking. In the second hydrolysis step, the liquid-state galactose was converted into levulinic acid via a high-temperature reaction in a batch reactor. As a result, the overall production yield of Gelidium amansii to levulinic acid in the two-step acid hydrolysis was approximately 20.6% on the initial biomass basis.

A Study on Characteristics of Solubilization and Biogas Production for Sewage Sludge using Thermal Pretreatment (열적가용화공정을 이용한 하수슬러지의 가용화 특성 및 바이오가스 생산량 평가)

  • Jeong, Seong-Yeob;Yeon, Ho-Suk;Lee, Chang-Yeol;Lee, Jong-In;Chang, Soon-Woong
    • Resources Recycling
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    • v.24 no.2
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    • pp.46-54
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    • 2015
  • In this study, an applicability of thermal pretreatment for primary and secondary sludge, which are generated in a sewage treatment plant, was evaluated. The efficiency and charateristics was investigated with each sludge after pretreatment under the condition of $100{\sim}220^{\circ}C$ for 30 minutes. As the result, it was found that $SCOD_{Cr}$, $NH_4{^+}$, VFAs concentrations increased as the pre-treatment temperature increased. For COD solubilization, it was also highly dependent on an increase of temperature resulting in acceleration on hydrolysis and acid fermentation. In the BMP (Biochemical Methane Potential) experiment, for the primary sludge, it showed the higher biogas production rate at a temperature of $220^{\circ}C$, however, the effect was insignificant (5.6%). Whereas, for the secondary sludge, the increase on biogass production rate was 38.8% ($180^{\circ}C$) and this means that the secondary sludge is more suitable for an applicability of thermal pretreatment.

Comparative Bioreactor Studies in Terms of Oxygen Transfer between Suspended and Immobilized Fungal Systems for Cyclosporin A Fermentation (Cyclosporin A 생산을 위한 액체배양과 고정화배양의 생물반응기에서의 산소전달 비교 연구)

  • 전계택
    • KSBB Journal
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    • v.9 no.2
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    • pp.211-223
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    • 1994
  • In fermentations with a 4-liter stirred tank bioreactor, a better than two-fold enhancement of the gas-liquid mass transfer coefficient$(k_La)$ in the celite-immobilized fungal cultures of Tolypocladium in flatum over the parallel conventional free-cell was observed at identical biomass concentrations, despite the higher specific oxygen uptake rate of the immobilized fungi during exponential growth. As a result oxygen sufficient conditions, i. e., dissolve oxygen(D.O.) concentrations exceeding 75% air saturation, could be maintained throughout exponential growth period of the immobilized culture, in contrast to the suspended fungal culture, whose D.O. levels fell below 50% air saturation. A linear monotonic dependence of $k_La$ upon impeller agitaion rate was found for both immobilized and conventional cultivation modes over a range of 250 to 550rpm, the slope being a function of biomass concentration for the free but not for the immobilized cell system In contrasts oxygen transfer rate was a much weaker function of aeration rate up to about 2.5 vvm for both culture configurations. Above this level, aeration rate had no further effect on the mass transfer. In addition, the immobilized cultures sustained good morphological and physiological states, leading to almost two times higher cyclosporln A (CyA) productivity overt the parallel free cell system. These experiments suggest that the celite-immobilized fungal system in a stirred tank reactor has considerable promise for scaling up cyclosporin A production in terms of high-density cultivation.

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Development of Osmotolerant Mutant, Candida magnoliae M26 and the Determination of the Optimum Concentrations of Carbon and Nitrogen Sources to Improve Erythritol Yield (에리스리톨의 수율 향상을 위한 Candida magnoliae의 삼투압 내성 변이균주의 개발과 탄소원 및 질소원의 최적 농도 결정)

  • 양성욱;서진호;유연우
    • KSBB Journal
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    • v.15 no.6
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    • pp.566-572
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    • 2000
  • Experimental studies were carried out to develop an osmotolerant mutant of Candida magnoliae JH and to determine the optimum concentrations of carbon and nitrogen sources to improve erythritol yield and productivity. Mutants of C. magnoliae JH were prepared by treatment with ethylmethane sulfonate, and osmotolerant mutants were isolated from the agar plate colonies containing 2.5 M KCI. Among the mutants isolated, one mutant M26 was finally selected based on erythritol yield and productivity. In shake flask culture, glucose proved to be the best carbon source and the optimum yeast extract concentration was 5 g/L based on 100 g/L glucose. The erythritol yield and productivity of mutant M26 were greater than wild type in 100 g/L glucose medium. in the fermentation experiments, erythritol production increased with increased glucose concentration, up to a limit of 250 g/L. The maximum concentration of erythritol achieved 127.5 g/L, and the yield and productivity of erythritol production were 51.0% and 0.63 g/L-h, respectively.

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Antimicrobial Activity of Korean Wild Tea Extract According to the Degree of Fermentation (발효정도에 따른 국내산 야생차 추출물의 항균활성)

  • Choi, Ok-Ja;Rhee, Haeng-Jae;Choi, Kyeong-Hee
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.34 no.2
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    • pp.148-157
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    • 2005
  • This study was investigated to determine antimicrobial activity of the water and ethanol extracts of Korean wild green tea, semi-fermented tea, and fermented tea. Antimicrobial activity was examined against 8 kinds of several microorganisms. The minimum inhibitory concentration (MIC) of the water and ethanol extracts of green tea showed the most active antimicrobial activity against B. subtilis 0.2 mg/mL in Gram positive bacteria and P. fluorescens 0.3∼0.5 mg/mL in Gram negative bacteria. But the extracts did not show antimicrobial activity against lactic acid bacteria and yeast at the level of less than 1 mg/mL. Antimicrobial activity got lower as tea got more fermented. Antimicrobial activity of ethanol extracts from green tea, semifermented tea, and fermented tea was stronger than that of water extracts. Antimicrobial activity of the water and ethanol extracts of green tea, semi-fermented tea, and fermented tea was not destroyed at 50∼121$^{\circ}C$, and pH 3∼11, which proved to be very stable when given over heat, acid & alkali treatment. The ethanol extract of green tea, semi-fermented tea, and fermented tea was fractionated in the order of hexane, diethyl ether, ethyl acetate and water fraction. The highest antimicrobial activity was found in the water fraction, but not found in hexane fraction, while antimicrobial activity of fermented tea was not found in ether fraction.

Extraction Equilibria of Succinic Acid by Using Aqueous Two Phases System Containing Imidazolium Ionic Liquids and Salts (이미다졸계 이온성액체와 염을 포함한 수상이성분계를 이용한 숙신산의 추출 평형)

  • Lee, Yong Hwa;Kang, Jeong Won;Hong, Yeon Ki;Kim, Ki-Sub
    • Clean Technology
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    • v.20 no.4
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    • pp.349-353
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    • 2014
  • Succinic acid is an important precursor in industries producing biopolymers, pharmaceutical and food additives and green solvents. However, due to the high price of petroleum and the global $CO_2$ emission, the biological production of succinic acid from renewable biomass is a novel process due to the fixation of $CO_2$ into succinate during fermentation. In this study, aqueous two phase systems based on imidazolium ionic liquids/$K_2HPO_4$ were used as an effective separation and concentration process for succinic acid. Experimental results show that aqueous two phase systems can be formed by adding appropriate amount of imidazolium ionic liquids to aqueous $K_2HPO_4$ solutions in the presence of succinic acid. It can be found that the ability of imidazolium ionic liquids for phase separation followed the order [HMIm][Br]${\fallingdotseq}$[OMIm][Br]>[BMIm][Br]>[EMIm][Br]. The maximum value of extraction efficiency for succinic acid was about 90% and the amount of coextracted water into top phase is proportional to the chain length of cation in imidazolium ionic liquids. It was concluded that the aqueous two phase systems composed of imidazolium ionic liquids/$K_2HPO_4$ was effective for the selective extraction and concentration of succinic acid.

Studies on Wax Gourd Wine (다이어트 와인 동아주 제조에 관한 연구)

  • Lee, Suk Kun
    • Korean Journal of Agricultural Science
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    • v.27 no.2
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    • pp.117-124
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    • 2000
  • Three kinds of the mashes of 15%, 20% and 25% of boiled wax gourd containing 15% of sugar were fermented by yeast at $5{\sim}10^{\circ}C$ for 100 days. After fermentation, total sugar content of 15% mash was 7.3%, 20% mash 5.0% and 25% mash 4.0% respectively. Also, it revealed that in reducing sugar content, 15% mash was 4.5%, 20% mash 3.4% and 25% mash 4.0%, respectively. In protein content, 15% mash was 10.1mg/ml, 20% mash 13.9mg/ml, 25% mash 10.9mgl/ml, and in amino acid content, 15% mash was $0.27{\mu}mol/ml$, 20% mash $0.51{\mu}mol/ml$, and 25% mash $0.31{\mu}mol/ml$, each. In case of pH, 15% mash was 3.85, 20% mash 3.76, and 25% mash 3.51. In acidity, 15% mash was 0.34%, 20% mash 0.84%, and 25% mash 1.35%, respectively. In the number of yeast cell, 15% mash was 0.34%, 20% mash 0.84%, and 25% mash 1.35%, respectively. In the number of yeast cell, 15% mash was 6.30 logCFU/ml, 20% mash 6.85 logCFU/ml, and 25% mash 8.45logCFU/ml, respectively. In ethanol content, 15% mash was 11.4%, 20% mash 12,4%, and 25% mash 11.5%, respectively. Succinic acid content ranges from 1,128~1,385mg/l. In Acetic acid, 20% mash showed 2,806 mg/l and 25% mash 4,952 mg/l by acidification. Five-grade scoring test of sensory evaluation showed that in its taste degree, 15% mash was 3.26, 20% mash 3.00 and 25% mash 2.46, respectively.

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A brief method for preparation of gintonin-enriched fraction from ginseng

  • Choi, Sun-Hye;Jung, Seok-Won;Kim, Hyun-Sook;Kim, Hyeon-Joong;Lee, Byung-Hwan;Kim, Joon Yong;Kim, Jung-Hyun;Hwang, Sung Hee;Rhim, Hyewon;Kim, Hyoung-Chun;Nah, Seung-Yeol
    • Journal of Ginseng Research
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    • v.39 no.4
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    • pp.398-405
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    • 2015
  • Background: Ginseng has been used as a tonic for invigoration of the human body. In a previous report, we identified a novel candidate responsible for the tonic role of ginseng, designated gintonin. Gintonin induces $[Ca^{2+}]_i$ transient in animal cells via lysophosphatidic acid receptor activation. Gintonin-mediated $[Ca^{2+}]_i$ transient is linked to anti-Alzheimer's activity in transgenic Alzheimer's disease animal model. The previous method for gintonin preparation included multiple steps. The aim of this study is to develop a simple method of gintonin fraction with a high yield. Methods: We developed a brief method to obtain gintonin using ethanol and water. We extracted ginseng with fermentation ethanol and fractionated the extract with water to obtain water-soluble and water-insoluble fractions. The water-insoluble precipitate, rather than the water-soluble supernatant, induced a large $[Ca^{2+}]_i$ transient in primary astrocytes. We designated this fraction as gintonin-enriched fraction (GEF). Results: The yield of GEF was approximately 6-fold higher than that obtained in the previous gintonin preparation method. The apparent molecular weight of GEF, determined using sodium dodecyl sulfate-polyacrylamide gel electrophoresis, was equivalent to that obtained in the previous gintonin preparation method. GEF induced $[Ca^{2+}]_i$ transient in cortical astrocytes. The effective dose (ED50) was $0.3{\pm}0.09{\mu}g/mL$. GEF used the same signal transduction pathway as gintonin during $[Ca^{2+}]_i$ transient induction in mouse cortical astrocytes. Conclusion: Because GEF can be prepared through water precipitation of ginseng ethanol extract and is easily reproducible with high yield, it could be commercially utilized for the development of gintoninderived functional health food and natural medicine.

Quality Properties of Jujube Yakju Based on the Adding Rate of Dried Jujube and Storage Periods (건조대추 첨가비율 및 저장기간에 따른 대추약주의 품질특성)

  • Choi, Jeong-Sil;Yeo, Soo-Hwan;Choi, Ji-Ho;Choi, Han-Seok;Jeong, Seok-Tae
    • Food Science and Preservation
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    • v.20 no.1
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    • pp.52-61
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    • 2013
  • This study was conducted not only to investigate the effects of rate of addition of dried jujube to Yakju (0, 0.5, 1.0, 1.5, 2.0 percent) but also to examine the quality changes in jujube Yakju during its storage (for 75 days at $35^{\circ}C$). The results showed no significant differences in pH, total acidity, soluble solids, and anthocyanin and alcohol contents of the Yakju right after its fermentation. With the increase in the amount of jujube that was added, the lightness of the jujube Yakju changed from 93 to 94, its redness decreased, and its yellowness significantly increased. The jujube Yakju that was fermented with 1.5-percent dried jujube had high sensory evaluation (selection rate) scores for color, flavor, taste and overall acceptability. It had no significant changes in pH and total acidity during its storage after its heat treatment. Its soluble solids contents tended to decrease with its heat treatment and to increase in its storage period. With respect to its color changes during its storage, the higher the ratio of the jujube that was added, the longer the storage period was, the lightness (L) and redness (a) decreased and the yellowness (b) increased. The polyphenol contents depended on the rate of addition of the dried jujube, but were not affected by the heat treatment and storage period. The organic acids in jujube Yakju were citric acid, succinic acid, lactic acid, malic acid and acetic acid.