• Title, Summary, Keyword: Yeast culture

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Biomass Production of Saccharomyces cerevisiae KFCC 10823 and Its Use in Preparation of Doenjang

  • Yoo, Jin-Young;Kim, Hyeon-Gyu;Kwon, Dong-Jin
    • Journal of Microbiology and Biotechnology
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    • v.7 no.1
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    • pp.75-80
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    • 1997
  • An ethanolic fermentation process was developed for preparing Doenjang with high ethanol. Higher and efficient viable cell production of salt-tolerant ethanolic yeast is a prerequisite for the successful commercial-scale process of ethanol production during Doenjang fermentation. Culture conditions of salt-tolerant yeast, S. cerevisiae KFCC 10823, was studied in terms of the effect of several environmental and nutritional factors. Viable cell numbers were the highest in a medium containing the following components per liter of water: soysauce, 300ml; dextrose, 50 g; beef extract, 5 g; yeast extract, 5 g; $KH_2PO_4$, 5 g; NaCl, 50 g. The optimal culture conditions of S. cerevisiae KFCC 10823 were pH 5.5, $25^{\circ}C$, 200 rpm and 0.5 vvm. Yeast viability during batch fermentation was gradually decreased to a level less than $90{\%}$ after 35 hours. The maximum cell number was $2.2{\times}10_7$ cells/ml at the optimal condition. Doenjang prepared with ethanolic yeast was ripened after 45 days at $30^{\circ}C$. This Doenjang contains 470 mg% of amino nitrogen and 2.5% ethanol. The shelf-life at $30^{\circ}C$ was theoretically estimated as 444 days.

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Effect of Medium Composition on Cell Growth and Bioethanol Production in Clostridium ljungdahlii Culture (Clostridium ljungdahlii 배양에서 배지 조성에 따른 균주 성장과 바이오에탄올 생산에 대한 영향)

  • Ahn, Bohye;Park, Soeun;Kim, Young-Kee
    • Applied Chemistry for Engineering
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    • v.29 no.4
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    • pp.419-424
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    • 2018
  • In this work, effect of the culture medium composition on the fermentation process of Clostridium ljungdahlii, which is acetogenic bacteria to product ethanol from synthesis gas, was examined to improve the microbial growth and ethanol production. Components of the culture medium such as yeast extract, fructose, $NH_4Cl$, and $K_2HPO_4$ were selected as influence factors for the cell growth and ethanol production. As the concentration of yeast extract increased, both of the cell growth and ethanol production increased. And the ethanol productivity was the highest at an yeast extract of 0.05 g/L, which is lower than that of base medium. As the concentration of fructose increased, the cell growth increased, but the ethanol production decreased when the concentration of fructose was higher than that of base medium (5 g/L). In an experiment with the yeast extract of 5 g/L, produced ethanol concentration was the highest (0.297 g/L) when fructose concentration was 5 g/L, however, the specific ethanol productivity was higher (0.281 g/g DCW) when the fructose was not added due to very low cell mass. The cell growth and ethanol production were not significantly influenced by $NH_4Cl$ concentration, however the growth inhibition was observed at a 30 g/L of $NH_4Cl$. When the concentration of $K_2HPO_4$ increased, both of the cell growth and ethanol production increased. In experiments with $NH_4Cl$ and $K_2HPO_4$, specific ethanol productivities were higher when the low concentration of yeast extract was used.

Isolation and Identification of Wild Yeast and Its Use for the Production of Grapewine (야생 효모의 분리.동정 및 이를 이용한 포도주 제조)

  • Kim, Jung-In;Lee, Nam-Keun;Hahm, Young-Tae
    • Korean Journal of Microbiology
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    • v.43 no.3
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    • pp.217-221
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    • 2007
  • The domestic cultured Campbell's Early and Geubong grapes were fermented far the production of red wines with the isolated wild yeast Saccharomyces cerevisiae IJ850. For the isolation of wild yeast, Geubong and Campbell's Early grapejuices were naturally fermented at room temperature for 6 days without adding stater culture. The strain isolated from Geubong which has 1.8 times higher fermentative ability than the strains isolated Campbell Early was selected. The selected strain was identified by using 26S rDNA sequencing. The strain showed 99.7% of similarity with Saccharomyces cerevisiae and thus identified as Saccharomyces cerevisiae IJ850. It was investigated the fermentative ability as the start culture. For the production of grapewine, the final sugar concentrations of grapejuices were adjusted to the $25^{\circ}Brix$ with anhydrous glucose. The grapejuices were fermented at room temperature for 10 days in the air-locked bottles filled with $CO_2$ gas. The final yield and alcohol concentration of Campbell's Early and Geubong grapewines fermented with the isolated wild yeast were 80.8%, 11.0% and 87.8%, 13.0%, respectively. Between the isolated wild yeast S. cerevisiae IJ850 and the commercial yeast S. cerevisiae EC1118, total acidities of grapewines produced with wild yeast were lower than those produced with the commercial yeast. The pH values and the values of color analysis of grapewines produced with both strains were similar. The total phenol contents of campbell's Early and Geubong wines produced with the isolated yeast and the commercial yeast were obtained in the range of 75 to 125mg/L. In conclusion, S. cerevesiae IJ850 isolated from the domestic cultured Geubong grape is able to use to produce grapewines as stater culture.

A Study on the Cooking and Processing Methods Presented in CHE MIN YO SUL -Jangs- (제민요술(濟民要術)에 수록된 식품조리 가공법 연구 (III) -장(醬)-)

  • Yoon, Seo-Seok;Yoon, Sook-Kyung;Cho, Hoo-Jong;Lee, Hyo-Gee;Ahn, Myong-Soo;Ahn, Sook-Ja;Suh, Hye-Kyung;Yoon, Duk-Ihn;Lim, Hee-Soo
    • Journal of the Korean Society of Food Culture
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    • v.6 no.2
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    • pp.141-146
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    • 1991
  • This is a study about Jangs presented in the Cheminyosul. Scattered yeast and purified salts are used as ingredients of Jangs. Hwangeui, Hwangjeung and Eol are scattered yeast, and Sangmanyom, Hwayom and Inyom are purified salts. According to their main ingredient, Jang can be classified Kokjang, Yukjang and Eojang. Kokjang was made from soybean and/or wheat, Yukjang made from meat, and Eojang made from fish and crustacea. Eojang is similar to Korean fish sauce, Jeot. Three kinds of Kokjang, four kinds of Yukjang and seven kinds of Eojang are described in the Cheminyosul. Generally, Jangs were fermented and ripened for one day to one hundred days. Also, most of Jangs were made in cold season except Keonjeeojang and Janghae.

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Expression and Secretion of Heterologous Protein in Yeast

  • Kim, Moo-Kyum;Song, Moo-Young;Yu, Myeong-Hee;Yu, Myeong-Hee;Park, Hee-Moon;Kim, Jinmi
    • Korean Journal of Microbiology
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    • v.30 no.2
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    • pp.108-112
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    • 1992
  • To investigate the expression and the secretion of heterologous proteins in yeast, we constructed an yeast secretion vector and produced a human secretory protein, .alpha.-1-antitrypsin (.alpha.-1-AT), from yeast cells. The secretion vector pGAT8 was constructed by inserting the signal sequence of yeast acid phosphatase gene (PH05) into the .alpha.1-AT expression vector pGAT6 which contained .alpha.-1-AT cDNA fused to GAL10-CYC1 promotor. The .alpha.-1-AT was produced efficiently in the yeast cells transformed with plasmid pGAT8, which was onfirmed both by the .alpha.-1-AT activity assay and by the immunoblot method using .alpha.-1-AT antibody. We also showed the secretion of .alpha.-1-AT into the culture media and into the periplasmic space by immunoblot.

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Strategy for Prevention of Weakly Flocculating Characters in Bottom Brewing Yeast Strains

  • Cheong, Chul;Wackerbauer, Karl;Kang, Soon-Ah
    • Food Science and Biotechnology
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    • v.17 no.3
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    • pp.558-563
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    • 2008
  • To prevent weakly flocculating characters of bottom brewing yeast during first fermentation, various technical investigations were carried out using strain of Saccharomyces cerevisiae. It appeared that the propagation at $10^{\circ}C$ promoted the molecular structure and biochemical composition of cell wall in favor of flocculation. The yeast grown at $20^{\circ}C$ by addition of zinc ion also had a stimulating effect on flocculation behavior during first fermentation cycle. The zinc ion did not influence directly on the changes of cell wall in favor of stronger flocculence. The increased fermentation activity of yeast due to addition zinc ion was rather responsible for the intensified flocculation capacity. It was concluded that the weakly flocculating characters of bottom brewing yeast during first fermentation can be solved by using yeast propagated at $10^{\circ}C$ or by means of yeast by addition of zinc ion during propagation.

Microbial Production of Yeast Cell Wall Lytic Enzymes (효모세포벽(酵母細胞壁) 용해효소(溶解酵素)의 미생물 생산(生産))

  • Kang, Soon-Young;Lee, Su-Rae;Lee, Chun-Yung
    • Korean Journal of Food Science and Technology
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    • v.9 no.2
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    • pp.97-105
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    • 1977
  • 1) In order to obtain a microbial strain having a strong yeast cell wall lytic activity, about 156 isolates capable of forming clear zones on baker's yeast-peptone-bouillon agar plate were obtained from soil, mud and water samples and a strain K-42 with the highest lytic activity was identified as Bacillus circulans. 2) Effect of carbon sources on the lytic enzyme production by the K-42 strain was in the decreasing order of maltose>glucan>xylose>control in 2-day culture and of lactose>galactose>glucan>control in 3-day culture. Effect of inorganic nitrogen sources was in the decreasing order of ammonium acetate>sodium nitrate>control in 2-day culture and of ammonium chloride>ammonium oxalate>control in 3-day culture, whereas organic nitrogen sources except milk casein showed an increase in 2-day culture and a decrease in 3-day culture. Synergistic effect of carbon sources and nitrogen sources was not observed. 3) The enzyme production by the K-42 strain was greatly affected by pH change of the culture medium, thus a high lytic activity could be maintained by keeping the pH range of $7{\sim}8$ and adding carbon or nitrogen sources. 4) Optimum conditions for the lytic activity of the K-42 strain were obtained at $pH\;7{\sim}8$ and $60^{\circ}C$ and the extent of hydrolysis toward heated yeast cell wall was 65%.

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Applications of Yeast Flocculation in Biotechnological Processes

  • Domingues, Lucilia;Vicente, Antonio A.;Lima, Nelson;Teixeira, Jose A.
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.5 no.4
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    • pp.288-305
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    • 2000
  • A review on the main aspects associated with yeast flocculation and its application in biotechnological processes is presented. This subject is addressed following three main aspects-the basics of yeast flocculation, the development of "new" flocculating yeast strains and bioreactor development. In what concerns the basics of yeast flocculation, the state of the art on the most relevant aspects of mechanism, physiology and genetics of yeast flocculation is reported. The construction of flocculating yeast strains includes not only the recombinant constitutive flocculent brewer's yeast, but also recombinant flocculent yeast for lactose metabolisation and ethanol production. Furthermore, recent work on the heterologous $\beta$-galactosidase production using a recombinant flocculent Saccharomyces cerevisiae is considered. As bioreactors using flocculating yeast cells have particular properties, mainly associated with a high solid phase hold-up, a section dedicated to its operation is presented. Aspects such as bioreactor productivity and culture stability as well as bioreactor hydrodynamics and mass transfer properties of flocculating cell cultures are considered. Finally, the paper concludes describing some of the applications of high cell density flocculating bioreactors and discussing potential new uses of these systems.e systems.

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Preparation of Corncob Grits as a Carrier for Immobilizing Yeast Cells for Ethanol Production

  • Lee, Sang-Eun;Lee, Choon Geun;Kang, Do Hyung;Lee, Hyeon-Yong;Jung, Kyung-Hwan
    • Journal of Microbiology and Biotechnology
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    • v.22 no.12
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    • pp.1673-1680
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    • 2012
  • In this study, DEAE-corncobs [delignified corncob grits derivatized with 2-(diethylamino)ethyl chloride hydrochloride ($DEAE{\cdot}HCl$)] were prepared as a carrier to immobilize yeast (Saccharomyces cerevisiae) for ethanol production. The immobilized yeast cell reactor produced ethanol under optimized $DEAE{\cdot}HCl$ derivatization and adsorption conditions between yeast cells and the DEAE-corncobs. When delignified corncob grit (3.0 g) was derivatized with 0.5M $DEAE{\cdot}HCl$, the yeast cell suspension ($OD_{600}$ = 3.0) was adsorbed at >90% of the initial cell $OD_{600}$. This amount of adsorbed yeast cells was estimated to be 5.36 mg-dry cells/g-DEAE corncobs. The $Q_{max}$ (the maximum cell adsorption by the carrier) of the DEAE-corncobs was estimated to be 25.1 (mg/g), based on a Languir model biosorption isotherm experiment. When we conducted a batch culture with medium recycling using the immobilized yeast cells, the yeast cells on DEAE-corncobs produced ethanol gradually, according to glucose consumption, without cells detaching from the DEAE-corncobs. We observed under electron microscopy that the yeast cells grew on the surface and in the holes of the DEAE-corncobs. In a future study, DEAE-corncobs and the immobilized yeast cell reactor system will contribute to bioethanol production from biomass hydrolysates.

Characteristics of Growth and Oil Production of Peppermint Cells in an Air-bubble Bioreactor (기포 생물반응기에서 페퍼민트 세포의 생육 및 정유 생산 특성)

  • 송은범;이형주
    • KSBB Journal
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    • v.8 no.5
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    • pp.495-503
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    • 1993
  • To investigate the characteristics of growth and oil production of peppermint cells during a batch culture, cells derived from peppermint callus was cultivated in an air bubble reactor. During the batch culture, effects of inoculum size, abiotic stress, yeast elicitor, and two stage culture on the cell growth, the productivity of oleolesin, and the formation of flavor components were determined and also the sugar concentrations and kinetics of cell growth were analyzed. Among the various sizes of inoculum, the culture with 2.0% packed cell volume inoculum showed the optimum condition for cell growth in the proposed bioreactor, and the cell yield and essential oil production reached to 5.7g/1 and 0.109g/1, respectively. When the abiotic stress of daily 8hr dark and $10^{\circ}C$ cold treatments were given to the culture cell growth decreased but essential oil production increased to 0.546g/l. In a modified Lin-Staba medium in which 100mg/l yeast extract as an elicitor was added to the culture, the cell growth and oil production increased, and menthol content was 22.5% of oil. In the two stage culture, in which the basic culture conditions of 27$^{\circ}C$, light, and without elicitor were employed during the first six days followed by the second stage with daily 8hr treatment of cold and dark condition, and also with yeast extract as an elicitor, cell growth decreased after eight days, essential oil production was not increased, and menthol was not detected. Dry cell yield was 0.38g dry cell/g sugar and specific growth rate was 0.25 day-1. The major terpenoid in the oil was not the menthol but pulegone and piperitone, precursors of menthol were accumulated. However, when yeast elicitor was added, menthol was produced to the level of 22.5% which was the highest value in the peppermint cell culture reported so far.

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