• Title, Summary, Keyword: Bacterial cellulose

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Mechanical Properties of Papers Prepared from Hardwood KP and Bacterial Cellulose (활엽수크라프트펄프 및 박테리아 셀룰로오스부터 제조한 종이의 물성)

  • 조남석;김영신;박종문;민두식;안드레레오노비치
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.29 no.4
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    • pp.53-63
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    • 1997
  • Most cellulose resources come from the higher plants, but bacteria also synthesize same cellulose as in plants. Many scientists have been widely studied on the bacterial cellulose, the process development, manufacturing, even marketing of cellulose fibers. The bacterial celluloses are very different in its physical and morphological structures. These fibers have many unique properties that are potentially and commercially beneficial. The fine fibers can produce a smooth paper with enchanced its strength property. But there gave been few reports on the mechanical properties of the processing of bacterial cellulose into structural materials. This study were performed to elucidate the mechanical properties of sheets prepared from bacterial cellulose. Also reinforcing effect of bacterial cellulose on the conventional pulp paper as well as surface structures by scanning electron microscopy were discussed. Paper made from bacterial cellulose is 10 times much stronger than ordinary chemical pulp sheet, and the mixing of bacterial cellulose has a remarkable reinforcing effect on the papers. Mechanical strengthes were increased with the increase of bacterial cellulose content in the sheet. This strength increase corresponds to the increasing water retention value and sheet density with the increase of bacterial cellulose content. Scanning electron micrographs were shown that fine microfibrills of bacterial celluloses covered on the surfaces of hardwood pulp fibers, and enhanced sheet strength by its intimate fiber bonding.

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Culture Condition for the Production of Bacterial Cellulose with Gluconacetobacter persimmonus KJ145 (Giuconacetobacter persimmonus KJ145를 이용한 Bacterial Cellulose 생산조건)

  • Lee, Oh-Seuk;Jang, Se-Young;Jeong, Yong-Jin
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.31 no.4
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    • pp.572-577
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    • 2002
  • We investigated the optimal condition for production of bacterial cellulose with Gluconacetobacter persimmonus KJ145. For bacterial cellulose production, optimal medium composition and culture conditions were conducted to determine. Apple juice (10$^{\circ}$Brix) medium was suitable than Hestrin & Schramm medium which is generally used for the bacterial cellulose production. When 1% pyruvate as carbon source was added to apple juice, bacterial cellulose production rose to high level. The effect of various nitrogen sources was investigated: CSL was found to be essential to high cellulose yields and the optimal CSL concentration was 10%. Optimal temperature and culture time for the bacterial cellulose production was 35$^{\circ}C$ and 16 days, respectively At the optimal condition Gluconacetobacter persimmonus KJ145 produced 8.96g/L of bacterial cellulose (dry weight), which was much higher than reported values.

Mechanical Properties of Hydrated Silk Fibroin/Bacterial Cellulose Composite Films (실크 피브로인/박테리아 셀룰로스 복합 필름의 수화 상태에서의 기계적 특성 변화)

  • Jung, Ri-Ra;Kim, Ye-Seul;Jin, Hyoung-Joon
    • Textile Science and Engineering
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    • v.44 no.3
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    • pp.130-133
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    • 2007
  • Composite films consisting of two biocompatible natural polymers were prepared by incorporating bacterial cellulose into silk fibroin. The high crystalline cellulose hydrogel was synthesized by bacteria, Acetobacter xylinum. Silk fibroin was finely blended with the bacterial cellulose fibrils by adding aqueous silk fibroin solution into the bacterial cellulose hydrogel. We observed individual bacterial cellulose fibrils within a silk fibroin matrix by field emission scanning electron microscopy. The silk fibroin well penetrated between the individual fibrils of the bacterial cellulose. The silk fibroin/bacterial cellulose composite film did not dissolve in water without further crystallization process, whereas a pure silk fibroin film easily dissolved in water without crystallization process. The crystallization phenomenon of silk fibroin in the composite film was verified by X-ray diffraction and Fourier transform-infrared spectroscopy. Furthermore, the mechanical properties of the silk fibroin/bacterial cellulose composite film markedly increased when the composite film was hydrated. The silk fibroin/bacterial cellulose composite films became more flexible and tougher when they were hydrated, while it was very brittle in the dehydrated state.

Effect of Filler Addition on Properties of Sheets Prepared from Bacterial Cellulose (박테리아 셀룰로오스 시트의 물성에 미치는 충전제의 첨가효과)

  • 조남석;민두식
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.30 no.4
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    • pp.35-41
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    • 1998
  • The bacterial cellulose has many unique properties that are potentially and commercially beneficial. In order to make opaque product from this cellulose, filling properties by fillers should be known. This study was performed to investigate the effect of filler addition on physical properties of sheets from bacterial cellulose. The effect of filling on its optical properties was also discussed. The apparent density and internal bonding strength of bacterial cellulose sheet are decreasing with the increase of filler contents. Those adversely affect Young's modulus and physical property of the sheet, but these negative phenomena of the bacterial cellulose sheet by filler addition are not so sensitive compared to substantial decreasing of physical properties of ordinary hardwood KP. This strength decrease would be attributed to the decrease of relative bonding sites among pulp fibers. Concerned to optical properties, the bacterial cellulose sheet shows high increase of brightness and opacity according to filler loading, but no significant changes in porosity up to 17.3% loading because of fine and filamentous structure of bacterial cellulose fibers.

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Development and Evaluation of the Biomimetic Actuator based on Bacterial Cellulose (박테리아 셀룰로오스 기반 생체모방 작동기 개발 및 평가)

  • Kim, Si-Seup;Kee, Chang-Doo
    • Journal of the Korean Society for Precision Engineering
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    • v.29 no.3
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    • pp.302-306
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    • 2012
  • Bacterial cellulose based actuator with large displacement was developed for biomimetic robots. Bacterial cellulose has 3D nanostructure with high porosity which was composed of the nanofibers. Freeze dried bacterial cellulose was dipped into ionic liquid solution such as 1-butyl-3-methylimidazolium(BMIMCl) to enhance the actuation performance due to increase the ionexchange capacity and ionic conductivity. And Poly(3,4-ethylenedioxythiophene)-poly (styrnenesulfonate)(PEDOT:PSS) was used for the electrodes of both side of bacterial cellulose actuator by dipping and drying method. The FT-IR and XRD were conducted to examine the electrochemical changes of developed bacterial cellulose actuator. The biomimetic caudal fin was designed using bacterial cellulose actuator and PDMS to verify the possibility for biomimetic robot. The step and harmonic response were conducted to evaluate the performance of developed biomimetic actuator.

Effect of Ethanol on the Production of Cellulose and Acetic Acid by Gluconacetobacter persimmonensis KJ145 (Gluconacetobacter persimmonensis KJ145를 이용한 Bacterial Cellulose 및 초산발효에 미치는 Ethanol의 영향)

  • 이오석;장세영;정용진
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.32 no.2
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    • pp.181-184
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    • 2003
  • We investigated the effect of ethanol on the production of cellulose and acetic acid fermentation by Gluconacetobacter persimmonensis KJ145. Results showed that bacterial cellulose productivity was highest when 2% ethyl alcohol was added to apple-juice medium. For acetic acid production, 7% ethyl alcohol was needed. Optimal concentration of ethyl alcohol was 5% for simultaneous production of bacterial cellulose and acetic acid. For simultaneous production of bacterial cellulose and acetic acid, optimal nitrogen source and optimal concentration were corn steep liquor and 15% (w/v), respectively Optimal culture time for simultaneous production of bacterial cellulose and acetic acid was 14 days. At the optimal condition, Cluconacetobacter persimmonenis KJ145 produced 7.55 g/L of bacterial cellulose (dry weight).

Production of Bacterial Cellulose by Gluconacetobacter hansenii PJK Isolated from Rotten Apple

  • Park, Joong-Kon;Park, Youn-Hee;Jung, Jae-Yong
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.8 no.2
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    • pp.83-88
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    • 2003
  • A cellulose-producing strain isolated from rotten apples was identified as Gluconacetobacter hansenii based on its physiological properties and the 16S rDNA complete sequencing method, and specifically named Gluconacetobacter hansenii PJK. The amount of bacterial cellulose (BC) produced by G. hansenii PJK in a shaking incubator was 1.5 times higher than that produced in a static culture. The addition of ethanol to the medium during cultivation enhanced the productivity of bacterial cellulose, plus the supplementation of 1% ethanol into the culture medium made the produced BC aggregate into a big lump and thus protected the bacterial-cellulose-producing G. hansenii PJK cells in the shear stress field from being converted into non-cellulose-producing (Cel) mutants. Cells subcultured three times in a medium containing ethanol retained their ability to produce BC without any loss in the production yield.

Production of Bacterial Cellulose and Its Modification (박테리아 셀룰로오스의 생산 및 개질)

  • 민두식;조남석;최태호
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.29 no.3
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    • pp.26-33
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    • 1997
  • The bacterial celluloses are very different in its physical, chemical and morphological structures compared to wood cellulose. These fibers have many unique properties that are potentially and commercially beneficial. This study was aimed to elucidate the production of bacterial celluloses and to improve their physical properties by chemical pretreatment. Bacterial celluloses produced by static culture had gel-like pellicle structure. The pellicle thickness was increased with the increasing time, and its layer was about 1.8cm after one-month incubation. The pellicles extruded from the cells of Acetobacter had a non-crystalline structure during initial growing stages, gradually getting crystaliyzed with the incubation time elapse, and eventually fumed to the cellulose I crystals. Young's modulus of bacterial cellulose sheet was increased with increasing NaOH concentration, and resulted in the highest at 5% NaOH concentration. Similar results with NaClO3 pretreatment can be observed. Too concentrated alkali solutions induced the destruction of cellulose fibrils and changed the mechanical properties of the sheets. These alkaline pretreatment have removed non-cellulosic components(NCC) from the bacterial cellulose, and enhanced inter-abrillar bonding by direct close contact among cellulosic fibrils.

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Quality Characteristics of Baikseolgi Added with the Bacterial Cellulose (Bacterial Cellulose 첨가 백설기의 품질특성)

  • Jang, Se-Young;Kim, Ok-Mi;Jeong, Yong-Jin
    • Korean Journal of Food Preservation
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    • v.12 no.5
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    • pp.455-459
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    • 2005
  • This study was investigated for the delaying effect of retrogradation and quality changes in baikseolgi added with bacterial cellulose. during storage From the result, the addition of more than 0.09% bacterial cellulose to baikseolgi showed lower level of retrogradation and a lower hardness than whithout any addition. There were no significant difference in sensory characteristics. However, the overall acceptability was higher in baikseolgi added with bacterial cellulose.

Properties of Bacterial Cellulose Cultured in Different Carbon Sources (탄소원에 따른 Bacterial Cellulose 의 물성)

  • Park, Sang-Min;Yoon, Sang-Jun;Son, Hong-Joo;Lee, Chung-Yeol;Kim, Hong-Sung
    • Polymer Korea
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    • v.34 no.6
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    • pp.522-526
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    • 2010
  • Bacterial cellulose is produced by the bacterium Gluconacetobacter xylinus, which forms a nanofibrous pellicle in its culture medium. We studied properties of the bacterial cellulose such as crystallinity, viscosity, morphology, and mechanical properties according to the carbon source. Static cultures of Gluconacetobacter sp. V6 were performed in three kinds of media: standard Hestrin-Schramm medium, and modified medium with either glycerol or molasses as carbon sources. Cell growth and cellulose yield were increased in the glycerol and molasses media. The culture in the glycerol medium improved the physical properties of cellulose such as crystallinity, intrinsic viscosity, and breaking stress. However, the culture in the molasses medium decreased crystallinity, crystallite size, and intrinsic viscosity of cellulose. In summary, the cellulose yield was remarkably improved in the molasses medium, but with inferior structural properties.