Chanprateep Suchada, Kulpreecha Songsri
Department of Microbiology, Faculty of Science, Chulalongkorn University, Phayathai, Bangkok 10330, Thailand.
J Biosci Bioeng. 2006 Jan;101(1):51-6. doi: 10.1263/jbb.101.51.
The production of the terpolymer poly(3-hydroxybutyrate-co-3-hydroxyvalerate-co-4-hydroxybutyrate), P(3HB-co-3HV-co-4HB), by Alcaligenes sp. A-04 was investigated to determine the superior biodegradable polymer properties over those of poly(3-hydroxybutyrate), P(3HB), and its copolymers. The highest terpolymer content of 68% (w/w) was produced by Alcaligenes sp. A-04 at 60 h by shake-flask cultivation. The terpolymer with 93 mol% 4HB mole fraction units was produced when the cultivation time was extended to 96 h. Moreover, it was found that Alcaligenes sp. A-04 could utilize 1,4-butanediol for the synthesis of 3HB and 4HB monomers as well as the sodium salt of 4-hydroxybutyrate. The terpolymer content was 30% (w/w) and the composition was P(33%3HB-co-16%3HV-co-51%4HB). Next, terpolymers with 4HB mole fraction units ranging from 50 to 90 mol% were produced by varying the medium composition and cultivation time. The thermal and mechanical properties of the resulting terpolymers were different from those of the copolymers with a similar mole fraction of monomer units. The terpolymer P(4%3HB-co-3%3HV-co-93%4HB) showed an elongation of 430%, a toughness of 33 MPa, and Young's modulus of 127 MPa similar to those of low-density polyethylene. The terpolymer P(11%3HB-co-34%3HV-co-55%4HB) showed Young's Modulus of 618 MPa similar to that of polypropylene.
研究了产碱杆菌属A-04生产三元共聚物聚（3-羟基丁酸酯-co-3-羟基戊酸酯-co-4-羟基丁酸酯），即P(3HB-co-3HV-co-4HB) 的情况，以确定其相较于聚（3-羟基丁酸酯），即P(3HB) 及其共聚物的优异生物可降解聚合物性能。通过摇瓶培养，产碱杆菌属A-04在60小时时产生了最高含量为68%（w/w）的三元共聚物。当培养时间延长至96小时时，产生了4HB摩尔分数单元为93 mol%的三元共聚物。此外，发现产碱杆菌属A-04能够利用1,4-丁二醇合成3HB和4HB单体以及4-羟基丁酸钠盐。三元共聚物含量为30%（w/w），组成是P(33%3HB-co-16%3HV-co-51%4HB)。接下来，通过改变培养基组成和培养时间，制备了4HB摩尔分数单元在50至90 mol%范围内的三元共聚物。所得三元共聚物的热性能和机械性能与具有相似摩尔分数单体单元的共聚物不同。三元共聚物P(4%3HB-co-3%3HV-co-93%4HB) 的伸长率为430%，韧性为33 MPa，杨氏模量为127 MPa，与低密度聚乙烯相似。三元共聚物P(11%3HB-co-34%3HV-co-55%4HB) 的杨氏模量为618 MPa，与聚丙烯相似。
