| Project/Area Number |
08455445
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
高分子構造・物性(含繊維)
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| Research Institution | HOKKAIDO UNIVERSITY |
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Principal Investigator |
TAKAI Mitsuo Hokkaido Univ., Grad.School of Eng., Prof., 大学院・工学研究科, 教授 (50002019)
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| Co-Investigator(Kenkyū-buntansha) |
TAJIMA Kenji Grad.School of Eng., Ass., 大学院・工学研究科, 助手 (00271643)
FUJIWARA Masashi Grad.School of Eng., Ass., 大学院・工学研究科, 助手 (30229075)
SHIBA Toshikazu Grad.School of Eng., Assoc.Prof., 大学院・工学研究科, 助教授 (60241303)
ERATA Tomoki Grad.School of Eng., Assoc.Prof., 大学院・工学研究科, 助教授 (30213581)
MUNEKATA Masanobu Grad.School of Eng., Prof., 大学院・工学研究科, 教授 (50261326)
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| Project Period (FY) |
1996 – 1997
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| Project Status |
Completed (Fiscal Year 1997)
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| Budget Amount *help |
¥5,300,000 (Direct Cost: ¥5,300,000)
Fiscal Year 1997: ¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 1996: ¥3,400,000 (Direct Cost: ¥3,400,000)
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| Keywords | Bacterial Cellulose (BC) / Water-soluble Polymer (WSP) / BC Composite (BCC) / Increasing Yield / Biodegradability Control / Bioreactor with rotating-disk / Vibratory Young's Modulus / 培地成分 / 酵母エキス / アミノ酸 / pH / グルコン酸 |
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| Research Abstract |
Bacterial cellulose (BC) productivity has been enhanced by the presence of 3.5% concentration of yeast extract in the medium as high as twice of the standard culture(0.5% yeast extract). Cell growth increased markedly with an increase in yeast extract concentration. pH of the medium decreased from the initial 5.9 to the range of 3.5-4.5 during 2 days incubation, however, after the prolonged incubation gradual increasing in pH was observed. Glucose as a carbon source was nevertheless consumed thoroughly during 4 days incubation, cellulose production proceeded slowly as long as 15 days incubation. An excess of yeast extract in the medium appear to play an role in the activator for cellulose biosynthesis. Bacterial cellulose (NBC) produced by Acetobacter xylinum (A.xylinum) has both great mechanical strength and biodegradability.The properties were controlled by the incorporation of water-soluble polymers (WSP) such as carboxymethyl cellulose (CMC), methyl cellulose (MC) and polyethylene
… More
glycol (PEG). Small amounts of the WSPs were added to the standerd Hestrin-Schramm medium.The WSPs were incorporated into BC during incubation. The cellulose composite (BCC) will be a kind of interpenetrating polymer.The BCC yield by weight were 1.5 times for MC and 1.8 times for CMC as compared with the weight of NBC control. The contents of MC and CMC in the BCC were checked by elemental analysis of C%, 45% for CMC and 20% for MC,respectively. From the X-ray analysis, the diffraction of (110) appeared sharply as a resuli of the disorientation of (110). The WSPs influence the preferential orientation of BC.Young's modulus of the BCC was about 1-3 times that of NBC (30-40GPa). BCC (CMC) was degraded completely by cellulase for 6 hr, while only 20-40% of BCC (MC) was degraded for 48hr. For degadation test in native soil, all BCC samples were degaded considerably at 30ﾟC for 4 weeks as well as NBC.There is some possibility to control a biodegadability of BC.The method of BCC production will be used to synthesize a new type of BC having both excellent biodegradability and other functions. The most effective incubation methods for NBC production were examined in various mode of bioreactor, and then on the basis of the results, the bioreactor with rotating-disk has been designed. Less
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