MOE Key Lab of Bioinformatics, Department of Biological Science and Biotechnology, School of Life Science, Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing 100084, China.
J Biotechnol. 2013 Jun 20;166(1-2):34-41. doi: 10.1016/j.jbiotec.2013.04.017. Epub 2013 May 4.
Polyhydroxyalkanoates (PHA), a family of diverse bio-polyesters, are produced by many bacteria as an energy and carbon storage material. PHA synthesis regulatory protein PhaR was reported to attach on the surface of intracellular PHA granules for convenience of synthesis regulation. PhaR was found to have an amphiphilic property. However, no study was conducted to exploit this property for applications as bio-surfactant and bactericide agent. Purified PhaR showed a higher emulsification ability than that of the widely used chemical surfactants including SDS, Tween 20, sodium oleate, and liquefied detergent (LD). PhaR also showed a higher emulsification ability than bio-surfactants rhamnose and PHA granules associated protein termed phasin or PhaP. Non-purified PhaR, namely, the native inclusion bodies and cell lysates, also demonstrated to be an excellent surfactant. PhaR was found highly stable even at 95 °C. In addition, PhaR was revealed to be a promising bactericidal agent against Gram positive and negative bacteria. PhaR can be conveniently produced by recombinant Escherichia coli. It has shown to be a bio-surfactant with excellent emulsification ability and strong bactericidal capacity at elevated temperature as high as 95 °C. Therefore, PhaR could be used in areas including food, beverage, pharmaceutical and cosmetics industries.
聚羟基脂肪酸酯（PHA）是一类多样化的生物聚酯，许多细菌会将其作为能量和碳储存物质进行合成。PHA 合成调控蛋白 PhaR 被报道会附着在细胞内 PHA 颗粒的表面，以方便进行合成调控。PhaR 被发现具有两亲性。然而，目前尚无研究利用这种特性将其开发为生物表面活性剂和杀菌剂。与广泛使用的化学表面活性剂（如 SDS、Tween 20、油酸和液体洗涤剂（LD））相比，纯化的 PhaR 表现出更高的乳化能力。PhaR 还显示出比生物表面活性剂鼠李糖和与 PHA 颗粒相关的蛋白（称为 phasin 或 PhaP）更高的乳化能力。非纯化的 PhaR，即天然包含体和细胞裂解物，也被证明是一种极好的表面活性剂。即使在 95°C 的高温下，PhaR 也表现出高度的稳定性。此外，PhaR 被证明是一种有前途的杀菌剂，可有效对抗革兰氏阳性菌和革兰氏阴性菌。PhaR 可通过重组大肠杆菌方便地生产。它已被证明是一种生物表面活性剂，在高达 95°C 的高温下具有优异的乳化能力和强大的杀菌能力。因此，PhaR 可用于食品、饮料、制药和化妆品等领域。
