Department of Microbiology and Molecular Biology, Chungnam National University, Daejeon 305-764, Republic of Korea.
Bioresour Technol. 2011 May;102(10):6159-66. doi: 10.1016/j.biortech.2011.03.025. Epub 2011 Mar 14.
The potential use of activated sludge for the production of medium-chain-length polyhydroxyalkanoates (MCL-PHAs) was investigated. The enrichment of bacterial populations capable of producing MCL-PHAs was achieved by periodic feeding with nonanoic acid in a sequencing batch reactor (SBR). Denaturing gradient gel electrophoresis analysis revealed Pseudomonas aeruginosa strains to be predominant in the bacterial community during the SBR process. The composition of PHA synthesized by the enriched biomass from nonanoic acid consisted of a large concentration (>89 mol%) of MCL monomer units and a small amount of short-chain-length monomer units. Under fed-batch fermentation with continuous feeding of nonanoic acid at a flow rate of 0.225 g/L/h and a C/N ratio of 40, a maximum PHA content of 48.6% dry cell weight and a conversion yield (Y(p/s)) of 0.94 g/g were achieved. These results indicate that MCL-PHA production by activated sludge is a promising alternative to typical pure culture approaches.
研究了活性污泥用于生产中链长聚羟基烷酸酯（MCL-PHAs）的潜力。通过在序批式反应器（SBR）中周期性地用壬酸进料，富集了能够生产 MCL-PHAs 的细菌种群。变性梯度凝胶电泳分析显示，在 SBR 过程中，铜绿假单胞菌菌株在细菌群落中占优势。由壬酸富集生物量合成的 PHA 的组成包含大量（>89 mol%）的 MCL 单体单元和少量的短链长单体单元。在连续进料的分批发酵中，以 0.225 g/L/h 的流速和 C/N 比为 40 连续进料壬酸，可实现最高 48.6%的 PHA 干重含量和 0.94 g/g 的转化率（Y(p/s)）。这些结果表明，活性污泥生产 MCL-PHA 是一种有前途的替代典型纯培养方法的选择。
