In this study, the performance of the selection process for polyhydroxyalkanoate (PHA) production from mixed microbial cultures (MMCs) at pilot scale was deeply investigated with the solid retention time (SRT) to cycle length (CL) ratio as main affecting parameter. Four different runs were tested by varying the SRT/CL ratio maintaining the same organic loading rate (OLR). The pilot-scale selection and accumulation reactors were fed with a fermented mixture of source-selected organic fraction of municipal solid waste (OFMSW) and waste activated sludge (WAS), refined with a centrifuge and membrane unit for the coarse solid removal. The selected biomass obtained in the most performing run was characterized by a specific storage rate of 375 mg COD_P/g COD_Xa h and a storage yield of 0.46 COD_P/COD_SOL. Accumulations performed with the same biomass were characterized by a storage yield of 0.62 COD_P/COD_VFA. The microbiome composition was assessed. In the most performing run, putative PHA-storing bacteria affiliated with Paracoccus genus were found at high abundance (36.8%), in contrast to all other runs. An overall PHA yield of 110 g PHA/kg VS was estimated for the best scenario, revealing an interesting perspective for biorefinery technology chains based on the three-stage process for PHA production.

中文翻译：

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来自城市有机废物的生物聚合物：固体保留时间对混合微生物培养物（MMC）富集的循环长度比的影响

在这项研究中，以固态停留时间（SRT）与循环长度（CL）之比为主要影响参数，对中试规模的混合微生物培养物（MMCs）生产聚羟基链烷酸酯（PHA）选择过程的性能进行了深入研究。通过改变SRT / CL比率以保持相同的有机负载率（OLR），测试了四个不同的运行。向中试规模的选择和累积反应器中加入城市固体废物（OFMSW）和废物活性污泥（WAS）的源选择有机部分的发酵混合物，并通过离心机和膜单元进行精制以去除粗固体。在最高性能运行中获得的选定生物质的特征在于比存储率为375 mg COD _P / g COD _Xah和0.46 COD _P / COD _SOL的储存产率。用相同的生物量进行的积累的特征在于储存产量为0.62 COD _P / COD _VFA。评估了微生物组组成。与其他所有运行相比，在性能最高的运行中，发现与副球菌属相关的PHA贮藏细菌的丰度很高（36.8％）。在最佳情况下，估计PHA的总产量为110 g PHA / kg V​​S，这揭示了基于PHA生产的三阶段过程的生物炼制技术链的有趣前景。