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Production and application of bacterial cellulose for a filler of composite materials.

复合材料填充剂细菌纤维素的制备及应用

基本信息

批准号：
02555180
负责人：
HAYASHI Jisuke
金额：
$ 3.46万
依托单位：
Hokkaido University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Developmental Scientific Research (B)
财政年份：
1990
资助国家：
日本
起止时间：
1990 至 1991
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-02555180/
关键词：
Composite material Cellulose in state single crystallite Bacterial cellulose Cellulase Calitivation medium Saccharification of biomass Synthetic gene of cellulose 複合材料フイラ-遺伝子組替

项目摘要

It was studied to use bacterial cellulose (BC) in the state of single crystallite as a filler for a composite material. BC membrane was stearlated to be given hydrophobicity and composed with epoxy resin. The ratios of tensile strength of the control without the filler and the composite matirials contained 13% of unmodified BC membrane and modified it in the degree of substitution of 2 were 1.0, 2.0, and 3.5 in the value corrected by specific gravity, respectively. Also, BC membrane and BC fiber microfibrilized with a homogenizer (MFBC) were modified by graft copolymerization with methylmetacrylate (MMA) and etc. and composed with epoxy resin and etc. Tensile strength of composite material of MFBC graft polymerized with MMA and epoxy resin increased 50% compared with that used unmodified MFBC.To decrease production cost of BC, solution obtained by enzymatic saccharification of cellulosic materials was used as cultivation medium. In contrast to presuppose amount of producted BC increased 30 to 70% compared with that used standard HS medium with pure glucase. It was cleared that the reason was brougth from the cellulase lost saccharification activity during heat sterilization. Addition of the modified cellulase into the HS medium brougth an increasing of almost 2 times in the yield of BC. Cellulase was seperated pure enzyme, endo-, exo-, and beta oxydase. the modified beta oxydase was most contributed to the increasing. It suggested that the modified enzayme provided a desirable situation for bonding of glucoses by forming a complex with them. The another reason was on the coexistence of mannose and galactose in some ratio with glucose.Shuttle vectrs for cellulose-producing Bacterium Acetobacter were diviloed. The vectors formed PFF6(4.8kB) from plasmid of the acetobactor and it of PUC18(2.7kB) from it of a colon bacillus was fit for insertion of pieces of foreign DNA, and had a high transformation efficiency of the level over 10^4/1ug.

研究了以单晶状态的细菌纤维素(BC)作为复合材料的填料。对BC膜进行硬脂化，使其具有疏水性，并与环氧树脂复合。未加填料的对照材料和含13%取代度为2的复合材料的拉伸强度之比分别为比重校正值的1.0、2.0和3.5。用甲基丙烯酸甲酯(MMA)等接枝共聚改性BC膜和均质剂微纤化的BC纤维(MFBC)，并与环氧树脂等复合，使MFBC的拉伸强度比未改性的MFBC提高50%。为了降低BC的生产成本，采用纤维素酶糖化液作为培养介质。与使用含纯葡萄糖酶的标准HS培养基相比，BC产量提高了30%~70%。明确了原因是热杀菌过程中纤维素酶失去糖化活性所致。在HS培养基中添加改性纤维素酶，可使BC产量提高近2倍。纤维素酶分为纯酶、内切酶、外切酶和β-加氧酶。修饰的β-加氧酶对酶活性的提高贡献最大。结果表明，修饰酶通过与葡萄糖形成络合物，为葡萄糖的成键提供了理想的条件。另一个原因是甘露糖和半乳糖与葡萄糖以一定比例共存。以乙酸乙酯为载体构建的PFF6(4.8kB)和PUC18(2.7kB)的载体适合插入外源DNA片段，转化效率可达104/1ug以上。