Development of Fermentation Production of New Microbial Polyesters

新型微生物聚酯发酵生产的研究进展

基本信息

批准号：
63850183
负责人：
DOI Yoshiharu
金额：
$ 5.31万
依托单位：
Tokyo Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Developmental Scientific Research (B).
财政年份：
1988
资助国家：
日本
起止时间：
1988 至 1990
项目状态：
已结题

项目摘要

A variety of microorganisms produce and accumulate a polyester in their cells as an energy source. The microbial polyester is a thermoplastic with biodegradable and biocompatible properties. Under optimal fermentation conditions, a microorganism produces a large amount of polyester at a high efficiency from alkanoic acids and alcohols. The content of polyester in dried cells increases up to 80 wt%.Recently, we have found that a new copolyester of 3-hydroxybutyrate (3HB) and 4-hydroxybutyrate (4HB) is produced by Alcaligenes eutrophus from various carbon sources of 4-hydroxybutyric acid, 1,4-butanediol, and butyrolactone. The composition of copolyesters varies from 0 to 60 mol-% 4HB units, depending on both fermentation conditions and carbon sources supplied. The physical and mechanical properties of P (3HB-co-4HB) are strongly dependent upon the copolymer compositions. The crystallinity of copolyester decreases with the 4HB fraction, and the strain of copolyester film increases from 5 to 444% at 16mol% 4HB. The copolyesters of over 40 mol% 4HB exhibit the mechanical properties of an elastic rubber. These copolyesters behave as thermoplastics with a melting point of 140-180^ﾟC and can be processed into transparent film and strong fiber by conventional extrusion and moulding equipment.The products of P (3HB-co-4HB) copolyesters are biodegradable in soil and activated sludge. The copolyester films were degraded after 6 weeks at 20-25^ﾟC in soil. Some microorganisms excrete extracellular depolymerases to degrade environmental polyesters into non-toxic monomers and utilize the decomposed compounds as nutrients. These microbial copolyesters have attracted much attention as environmentally degradable bioplastics for a wide range of agricultural, marine, and medical applications.

多种微生物作为能源在其细胞中产生并积聚聚酯。微生物聚酯是具有可生物降解和生物相容性特性的热塑性塑料。在最佳发酵条件下，微生物以高效率的烷酸和醇产生大量聚酯。干细胞中聚酯的含量增加了80 wt％。我们发现，新的3-羟基丁酸（3HB）和4-羟基丁酸（4HB）的新共聚酯是由Alcaligenes烯烃由4-羟基酸源的各种碳来源产生的。共溶植物从0到60 mol-％4HB单位的组成，具体取决于发酵条件和提供的碳源。 P（3HB-CO-4HB）的物理和机械性能很大程度上取决于共聚物组成。在4HB的馏分中，共溶性酯的结晶度降低，而在16mol％4HB时，共溶性膜的应变从5增加到444％。超过40 mol％4HB的共溶液暴露了弹性橡胶的机械性能。这些共产剂以140-180^c的熔点为热塑料，可以通过常规延伸和成型设备处理成透明的膜和强纤维。P（3HB-CO-4HB）的产物在土壤中可生物降解的p（3HB-CO-4HB）的产物。在土壤中，在20-25^c的6周后，聚座膜在6周后降解。一些微生物极端的细胞外解聚酶将环境聚酯降解为无毒的单体，并利用分解化合物作为营养素。这些微生物共聚物吸引了广泛的关注，因为在各种农业，海洋和医疗应用方面，可环境降解的生物塑料。