Salinity effect on production of PHA and EPS by Haloferax mediterranei
Salinity effect on production of PHA and EPS by Haloferax mediterranei
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盐度对地中海Haloferax mediterranei生产PHA和EPS的影响
DOI：
10.1039/c7ra09652f
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发表时间：
2017-01-01
期刊：
影响因子：
3.9
通讯作者：
Wang, Zhiwu (Drew)
中科院分区：
文献类型：
--
作者：
Cui, You-Wei;Gong, Xiao-Yu;Wang, Zhiwu (Drew)
嗜盐古细菌Haloferax Mediterranei能够大量生产聚羟基烷酸酯(PHAs)。随着H.Mediterranei合成PHAs的同时，一种胞外聚合物(EPS)作为副产物被排出，降低了PHAs的生产效率。本实验探讨了盐度对PHAs和/或EPS合成过程中碳分布的影响，以控制它们的生产。结果表明，高浓度的氯化钠抑制了EPS的产生，而促进了PHA的产生。最适盐度为150~200g L-1。随着氯化钠浓度从75g L-1增加到250g L-1，胞外多糖产率从371.36 mg/gCDW下降到319.74 mg/gCDW。然而，高盐度促进了PHAs的合成。当盐浓度为250g L-1时，胞内PHAs含量达到最大值71.1%。这一结果表明，高盐浓度显著促进了PHAs的产生，而抑制了EPS的产生。本研究提供了一种可能的解决方案，通过控制氯化钠浓度来调节麦迪氏梭菌合成PHAs和EPS的碳分布。
The halophilic archaeon, Haloferax mediterranei, is able to produce polyhydroxyalkanoates (PHAs) in large quantities. Along with the synthesis of PHAs by H. mediterranei, an extracellular polymeric substance (EPS) is excreted as a byproduct, lowering the efficiency of the production of PHAs. In this experiment, salinity effects on the carbon distribution to synthesis of PHAs and/or EPS were explored in order to control their production. It was found that high NaCl concentrations inhibited the productivity of EPS while encouraging the productivity of PHAs. The optimal salinity for the growth and proliferation of H. mediterranei was in the range of 150-200 g L-1. EPS productivity decreased from 371.36 to 319.74 mg EPS per g CDW as the concentration of NaCl increased from 75 g L-1 to 250 g L-1. However, high salinity promoted the synthesis of PHAs. When the NaCl concentration was 250 g L-1, the intracellular content of PHAs reached a maximum of 71.1%. This result indicated that a high NaCl concentration significantly stimulated the production of PHAs while depressing the production of EPS. This study provided a possible solution to adjust the carbon distribution to the synthesis of PHAs and EPS by H. mediterranei by controlling the concentration of NaCl.