• Microbiology and Biotechnology Letters
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• v.21 no.4
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• pp.366-372
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• 1993

The aim of this study was to find out the rapid fermentation of soy sauce from koji hydrolyzate using column type reactor packed with immobilized yeast cells. Each immobilized cell of Zygosaccharomyces rouxii BH-90 and Candida versatilis BH-91 in the packed column type reactor produced 2.8% ethyl alcohol and 18mg/l 4-ethylguaiacol over 96 hours under the optimal condition. Continuous fermentation was performed by immobilized Z. rouxii BH-90 packed in column type reactor. Immobilized Z. rouxii BH-90 produced 2.30~2.85% ethyl alcohol during 30 days, and decreased gradually from 40 days to 80 days. Also C. versatilis BH-91 produced 4-ethylguaiacol at the constant rate of 16~18mg/l and decreased gradually after 40 days. Final product of soy sauce contained 2.8% ethyl alcohol and 18mg/l 4-ethylguaiacol. However, amino acid compositions of final products were consisted of predominantly glutamic acid, leucine, arginine, aspartic acid, lysine and valine, which were more than 50% of total amino acid.

• Microbiology and Biotechnology Letters
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• v.19 no.4
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• pp.390-397
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• 1991

Ethanol production by calcium alginate-immobilized baker's yeast (Saccharor/tyces cereviszae) was studied in the batch fermentation using glucose medium as a feed. Immobilied cells were stable between $30^{\circ}C$ and $40^{\circ}C$ whereas free cells were stable between $30^{\circ}C$ and $37^{\circ}C$ The beads were showed constant ethanol productivity during 720 hours (30 days) over. Fermentation characteristics of immobilized baker's yeast were examined changing the initial glucose concentration of broth in fermentation. Initial glucose concentrations employed were 50, 100, 150 and 200 g/l, respectively. In 15% gucose medium, maximum specific growth rate, maximum ethanol yield and ethanol concentration were observed as 0.092 $h^{-1}$, 0.45, 67.5 g/l, respectively.

• Mycobiology
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• v.40 no.1
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• pp.35-41
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• 2012

A repeated batch fermentation system was used to produce ethanol using $Saccharomyces$ $cerevisiae$ strain (NCIM 3640) immobilized on sugarcane ($Saccharum$ $officinarum$ L.) pieces. For comparison free cells were also used to produce ethanol by repeated batch fermentation. Scanning electron microscopy evidently showed that cell immobilization resulted in firm adsorption of the yeast cells within subsurface cavities, capillary flow through the vessels of the vascular bundle structure, and attachment of the yeast to the surface of the sugarcane pieces. Repeated batch fermentations using sugarcane supported biocatalyst were successfully carried out for at least ten times without any significant loss in ethanol production from sugarcane juice and molasses. The number of cells attached to the support increased during the fermentation process, and fewer yeast cells leaked into fermentation broth. Ethanol concentrations (about 72.65-76.28 g/L in an average value) and ethanol productivities (about 2.27-2.36 g/L/hr in an average value) were high and stable, and residual sugar concentrations were low in all fermentations (0.9-3.25 g/L) with conversions ranging from 98.03-99.43%, showing efficiency 91.57-95.43 and operational stability of biocatalyst for ethanol fermentation. The results of the work pertaining to the use of sugarcane as immobilized yeast support could be promising for industrial fermentations.

• The Microorganisms and Industry
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• v.19 no.4
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• pp.2-13
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• 1993

Some microorganisms, including actinomycetes, cyanobacteria, and other bacteria, algae, fungi, and yeast, can accumulate and retain relatively high quantities of heavy metals and radionuclides from their external environments (1-4). Both living and dead cells can be used for biosorptive metal/radionuclide removal from solution. Thus microorganisms and products excreted by or derived from microbial cells (2) may provide an alternative or adjunct to conventional techniuqes of metal removal and recovery. Recent approaches have separated the microbial growth and metal removal process to manipulate production of metal-adsorptive capacity of bacteria and metal removal process. If pre-grown cells are immobilized and used for metal removal, mathematical modeling can be applied to predict immobilized cell reactor behavior under specific process conditions. Waste and microbial adsorbent could be separated from the treated flow in one step. Once treated, the metal waste is concentrated in a small volume of sorbed form for easy metal disposal or recovery.

• Mycobiology
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• v.42 no.3
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• pp.305-309
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• 2014

We investigated a novel process for production of ethanol from glycerol using the yeast Pachysolen tannophilus. After optimization of the fermentation medium, repeated-batch flask culture was performed over a period of 378 hr using yeast cells immobilized on Celite. Our results indicated that the use of Celite for immobilization of P. tannophilus was a practical approach for ethanol production from glycerol, and should be suitable for industrial ethanol production.

• Journal of the Korean Professional Engineers Association
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• v.21 no.2
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• pp.13-18
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• 1988

A Study for ethanol fermentation with immobilized yeast that is entrapped to Ca-alginate beads and batch system was carried out using molasses as substrate. The results are as follows. 1. The yield of alcohol fermentation is more efficacious then that of conventional fermentation process. The beads were used 15times and got a result of fermentation yield rate 89. 57％∼92.35％f, which is comparable with the rate of 86.3％ gained from the conventional fermentation process. 2. The concentration of Ca-alginate was 1∼5％ For long run use (2520 hours) it is necessary 2％ or more concentration of Ca-alginate. 3. The amount of the yeast cells for entrap to Ca-alginate beads was required 1.0g (indried material) or more for 200g Ca-alginate beads.

• Journal of Microbiology and Biotechnology
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• v.30 no.8
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• pp.1227-1234
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• 2020

In this study, yeast cell immobilization was carried out in a packed bed reactor (PBR) to investigate the effects of the volumetric capacity of carriers as well as the different fermentation modes on fuel ethanol production. An optimal volumetric capacity of 10 g/l was found to obtain a high cell concentration. The productivity of immobilized cell fermentation was 16% higher than that of suspended-cell fermentation in batch and it reached a higher value of 4.28 g/l/h in repeated batches. Additionally, using this method, the ethanol yield (95.88%) was found to be higher than that of other tested methods due to low concentrations of residual sugars and free cells. Continuous ethanol production using four bioreactors showed a higher productivity (9.57 g/l/h) and yield (96.96%) with an ethanol concentration of 104.65 g/l obtained from 219.42 g/l of initial total sugar at a dilution rate of 0.092 h^-1. Furthermore, we reversed the substrate-feed flow directions in the in-series bioreactors to keep the cells at their highest activity and to extend the length of continuous fermentation. Our study demonstrates an effective method of ethanol production with a new immobilized approach, and that by switching the flow directions, traditional continuous fermentation can be greatly improved, which could have practical and broad implications in industrial applications.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 1979.04a
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• pp.115.4-116
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• 1979

Acetone-dried cells of Arthrobacter simplex were entrapped in several preparations of hydrophilic urethane prepolymers and their steroid converting ability was examined. SeVeral solvents, such as methanol and propylone glycol, wereeffective for the conversion of hydrocortisone to prednisolone. The stability of the immobilized cells during storage and on repeated reactions was also examined. Thisconvenient entrapping method was also applicable for the immobilization of cellular organelles. yeast peroxisomes. The entrapped peroxi-somessh owed the activities of alcohol oxidase and catalase.

• Mycobiology
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• v.42 no.3
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• pp.249-255
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• 2014

We evaluated a more practical and cost-effective immobilization carriers for ethanol production using the yeast Saccharomyces cerevisiae. Three candidate materials-rice hull, rice straw, and sawdust-were tested for their cell-adsorption capacity and operational durability. Derivatizations of rice hull, rice straw, and sawdust with the optimal concentration of 0.5 M of 2-(diethylamino)ethyl chloride hydrochloride (DEAE HCl) resulted in > 95% adsorption of the initial yeast cells at 2 hr for DEAE-rice hull and DEAE-sawdust and in only approximately 80% adsorption for DEAE-rice straw. In addition, DEAE-sawdust was found to be a more practical carrier for immobilizing yeast cells in terms of operational durability in shaking flask cultures with two different speeds of 60 and 150 rpm. Furthermore, the biosorption isotherms of DEAE-rice hull, -rice straw, and -sawdust for yeast cells revealed that the $Q_{max}$ of DEAE-sawdust (82.6 mg/g) was greater than that of DEAE-rice hull and DEAE-rice straw. During the 404-hr of continuous column reactor operation using yeast cells immobilized on DEAE-sawdust, no serious detachment of the yeast cells from the DEAE-sawdust was recorded. Ethanol yield of approximately 3.04 g/L was produced steadily, and glucose was completely converted to ethanol at a yield of 0.375 g-ethanol/g-glucose (73.4% of the theoretical value). Thus, sawdust is a promising practical immobilization carrier for ethanol production, with significance in the production of bioethanol as a biofuel.

• Journal of Life Science
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• v.22 no.4
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• pp.508-515
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• 2012

In this study, DEAE-cotton [derivatized by 2-(diethylamino)ethyl chloride hydrochloride (DEAE HCl)] was prepared as a carrier for immobilized $Pichia$ $stipitis$ for ethanol production. When cotton was derivatized with 0.5 M DEAE HCl, the yeast cell suspension was adsorbed at 100% of the initial cell $OD_{600}$. The adsorbed yeast cells were estimated to be 101.8 mg-dry cells/g-DEAE-cotton. In particular, when a flask culture using the immobilized yeast cells was conducted in a glucose and xylose-containing medium, the yeast cells on the DEAE-cotton gradually produced ethanol, according to glucose and xylose consumption; the ethanol yield was approximately 0.33 g-ethanol/g-monosaccharide. Because DEAE-cotton was successfully used as a carrier for ethanol production from a glucose and xylose-containing medium, we expect that this bioethanol production process may be used for the bioethanol production process from the hydrolysate of lignocellulosic biomass. All the results of DEAE-cotton were compared with those of DEAE-cellulose as a carrier for immobilization.