Wang Qi, Yang Peng, Xian Mo, Liu Hui, Cao Yujin, Yang Ying, Zhao Guang
CAS Key Laboratory of Biobased Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China.
University of Chinese Academy of Sciences, Beijing 100049, China.
ACS Macro Lett. 2013 Nov 19;2(11):996-1000. doi: 10.1021/mz400446g. Epub 2013 Oct 22.
The block copolymers poly(3-hydroxybutyrate)--poly(3-hydroxypropionate) (P3HB--P3HP) with a wide range of 3HP fractions from 7.4 mol % to 75 mol % were biosynthesized from inexpensive carbon sources for the first time, differing from previously reported approaches based on sequential addition of precursors. The engineered strain carried two parallel synthetic pathways modulated by independent regulatory systems to produce the 3HB and 3HP monomers, respectively. Manipulating the expression levels of 3HB and 3HP pathways resulted in biosynthesis of block copolymers P3HB--P3HP with varied compositions. Nuclear magnetic resonance and differential scanning calorimetric studies demonstrated novel microstructure and thermal properties not available in related random copolymers and a blend of P3HB and P3HP homopolymers.
首次从廉价碳源生物合成了3HP含量范围为7.4摩尔%至75摩尔%的嵌段共聚物聚（3-羟基丁酸酯）-聚（3-羟基丙酸酯）（P3HB-P3HP），这与先前报道的基于顺序添加前体的方法不同。该工程菌株携带两条由独立调节系统调节的平行合成途径，分别产生3HB和3HP单体。操纵3HB和3HP途径的表达水平导致了不同组成的嵌段共聚物P3HB-P3HP的生物合成。核磁共振和差示扫描量热研究表明，相关无规共聚物以及P3HB和P3HP均聚物的共混物中不存在这种新型微观结构和热性能。
