School of Chemical Engineering and Analytical Science, The Mill , The University of Manchester , Manchester M13 9PL , U.K.
Biomacromolecules. 2018 Mar 12;19(3):996-1005. doi: 10.1021/acs.biomac.7b01788. Epub 2018 Feb 9.
Volatile fatty acids (VFA) C2:0 to C6:0 were used as the sole carbon source for poly(3-hydroxybutyrate- co-3-hydroxyvalerate) (PHBV) production with controllable composition and microstructure in Haloferax mediterranei. Feeding carbon-even VFA gave >90 mol % poly(3-hydroxybutyrate) (3HB) PHBV, while carbon-odd VFA generated >87 mol % poly(3-hydroxyvalerate) (3HV) PHBV. Bespoke random, block, and blend copolymers with 0-100 mol % 3HV were synthesized using C4:0/C5:0 mixtures. The copolymer 3HV fraction is proportional to the %C5:0 in the feed mixture, allowing control over copolymer composition. Microstructure depends on the substrate addition order: cofeeding generated random copolymers, while sequential feeding created block and blend copolymers. On average, the PHBV had an ultrahigh molecular weight of 3 × 10 g/mol. 3HV rich copolymers showed lower melting temperatures, enhanced elasticity, and ductility. H. mediterranei is ideal for large-scale production of PHBV due to its inherent bioprocessing advantages, while control over the composition and microstructure of PHBV will facilitate the production of biopolymers capable of meeting industrial criteria for specific applications.
挥发性脂肪酸 (VFA) C2:0 到 C6:0 被用作唯一碳源，用于生产聚 (3-羟基丁酸酯-共-3-羟基戊酸酯) (PHBV)，在盐单胞菌属地中海种中具有可控的组成和微观结构。以等摩尔比的 VFA 进料可得到 >90 mol % 的聚 (3-羟基丁酸酯) (3HB) PHBV，而以碳奇数 VFA 进料可得到 >87 mol % 的聚 (3-羟基戊酸酯) (3HV) PHBV。使用 C4:0/C5:0 混合物合成了具有 0-100 mol % 3HV 的定制无规、嵌段和共混共聚物。共聚物中 3HV 部分与进料混合物中的 %C5:0 成正比，可控制共聚物组成。微观结构取决于基质的添加顺序：共进料生成无规共聚物，而顺序进料则生成嵌段和共混共聚物。平均而言，PHBV 的重均分子量为 3×10^6 g/mol。3HV 丰富的共聚物具有较低的熔点、增强的弹性和延展性。盐单胞菌属地中海种由于其内在的生物加工优势，非常适合 PHBV 的大规模生产，而对 PHBV 组成和微观结构的控制将有助于生产能够满足特定应用工业标准的生物聚合物。
