Dept. of Environmental and Forest Biology, SUNY-College of Environmental Science and Forestry, Syracuse, NY 13210, USA.
Biotechnol Prog. 2010 Mar-Apr;26(2):424-30. doi: 10.1002/btpr.355.
Glycerol, a byproduct of the biodiesel industry, can be used by bacteria as an inexpensive carbon source for the production of value-added biodegradable polyhydroxyalkanoates (PHAs). Burkholderia cepacia ATCC 17759 synthesized poly-3-hydroxybutyrate (PHB) from glycerol concentrations ranging from 3% to 9% (v/v). Increasing the glycerol concentration results in a gradual reduction of biomass, PHA yield, and molecular mass (M(n) and M(w)) of PHB. The molecular mass of PHB produced utilizing xylose as a carbon source is also decreased by the addition of glycerol as a secondary carbon source dependent on the time and concentration of the addition. (1)H-NMR revealed that molecular masses decreased due to the esterification of glycerol with PHB resulting in chain termination (end-capping). However, melting temperature and glass transition temperature of the end-capped polymers showed no significant difference when compared to the xylose-based PHB. The fermentation was successfully scaled up to 200 L for PHB production and the yield of dry biomass and PHB were 23.6 g/L and 7.4 g/L, respectively.
甘油是生物柴油工业的副产品，可以被细菌用作生产有价值的可生物降解的聚羟基烷酸酯（PHA）的廉价碳源。洋葱伯克霍尔德氏菌（Burkholderia cepacia）ATCC 17759 可以从 3%到 9%（v/v）的甘油浓度中合成聚-3-羟基丁酸酯（PHB）。增加甘油浓度会导致生物量、PHA 产率和 PHB 的分子量（M(n)和 M(w)）逐渐降低。当添加甘油作为辅助碳源时，利用木糖作为碳源生产的 PHB 的分子量也会降低，这取决于添加的时间和浓度。（1）H-NMR 表明，由于甘油与 PHB 的酯化反应导致链终止（端封），分子量降低。然而，与基于木糖的 PHB 相比，端封聚合物的熔融温度和玻璃化转变温度没有显著差异。发酵成功扩大到 200 L 进行 PHB 生产，干生物量和 PHB 的产率分别为 23.6 g/L 和 7.4 g/L。
