Department of Molecular and Applied Biosciences, University of Westminster, London W1W 6UW, UK.
Biomacromolecules. 2011 Jun 13;12(6):2126-36. doi: 10.1021/bm2001999. Epub 2011 May 25.
Pseudomonas mendocina was found to produce a unique homopolymer of poly(3-hydroxyoctanoate), P(3HO), rather than a copolymer, when grown on sodium octanoate as the sole carbon source. Although this polymer has been produced by other organisms, interestingly this is the first time an absolute homopolymer has been produced by a wild type organism. In addition, a detailed study on the effects of different extraction methods on the yield, molecular weight, thermal properties, and lipopolysaccharide content of P(3HO) has been carried out. The organism was able to accumulate P(3HO) up to 31.38% of its dry cell weight within 48 h in mineral salt medium. Characterization of the monomer was carried out using FTIR, GC-MS, (13)C, (1)H, and HSQC NMR spectroscopy. The polymer had a crystallinity of 37.5%, Young's modulus value of 11.6 MPa and contact angle of 77.3°. Microstructural studies of solvent cast polymer films revealed a smooth surface topography with a root-mean-square roughness value of 0.238 μm.
门多西纳假单胞菌在以辛酸纳为唯一碳源生长时，产生了独特的聚（3-羟基辛酸酯）P（3HO）均聚物，而不是共聚物。虽然这种聚合物已被其他生物体产生，但有趣的是，这是第一个由野生型生物体产生的绝对均聚物。此外，还对不同提取方法对 P（3HO）的产率、分子量、热性能和脂多糖含量的影响进行了详细研究。该生物体能够在无机盐培养基中在 48 小时内将 P（3HO）积累到其干重的 31.38%。使用傅里叶变换红外光谱（FTIR）、气相色谱-质谱联用（GC-MS）、（13）C、（1）H 和 HSQC NMR 光谱对单体进行了表征。聚合物的结晶度为 37.5%，杨氏模量值为 11.6 MPa，接触角为 77.3°。溶剂浇铸聚合物薄膜的微观结构研究表明，表面具有光滑的形貌，均方根粗糙度值为 0.238 μm。
