A new method based on the GC-MS analysis of thermolysis products obtained by treating bacterial samples at a high temperature (above 270°C) has been developed. This method, here named "In-Vial-Thermolysis" (IVT), allowed for the simultaneous determination of short-chain-length polyhydroxyalkanoates (scl-PHA) content and composition. The method was applied to both single strains and microbial mixed cultures (MMC) fed with different carbon sources. The IVT procedure provided similar analytical performances compared to previous Py-GC-MS and Py-GC-FID methods, suggesting a similar application for PHA quantitation in bacterial cells. Results from the IVT procedure and the traditional methanolysis method were compared; the correlation between the two datasets was fit for the purpose, giving a R2 of 0.975. In search of further simplification, the rationale of IVT was exploited for the development of a "field method" based on the titration of thermolyzed samples with sodium hydrogen carbonate to quantify PHA inside bacterial cells. The accuracy of the IVT method was fit for the purpose. These results lead to the possibility for the on-line measurement of PHA productivity. Moreover, they allow for the fast and inexpensive quantification/characterization of PHA for biotechnological process control, as well as investigation over various bacterial communities and/or feeding strategies.

中文翻译：

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通过小瓶热解 (IVT) 快速测定细菌样品中短链聚羟基链烷酸酯 (scl-PHA) 的方法

开发了一种基于 GC-MS 分析高温（高于 270°C）处理细菌样品获得的热解产物的新方法。这种方法在此称为“瓶内热解”(IVT)，可以同时测定短链聚羟基链烷酸酯 (scl-PHA) 的含量和组成。该方法适用于用不同碳源喂养的单一菌株和微生物混合培养物 (MMC)。与之前的 Py-GC-MS 和 Py-GC-FID 方法相比，IVT 程序提供了类似的分析性能，表明在细菌细胞中进行 PHA 定量的应用类似。比较了 IVT 程序和传统甲醇分解方法的结果；两个数据集之间的相关性符合此目的，R2 为 0.975。为了进一步简化，IVT 的基本原理被用于开发一种“现场方法”，该方法基于用碳酸氢钠滴定热解样品来量化细菌细胞内的 PHA。IVT 方法的准确性符合此目的。这些结果导致在线测量 PHA 生产力的可能性。此外，它们允许对用于生物技术过程控制的 PHA 进行快速和廉价的量化/表征，以及对各种细菌群落和/或饲养策略的调查。这些结果导致在线测量 PHA 生产力的可能性。此外，它们允许对用于生物技术过程控制的 PHA 进行快速和廉价的量化/表征，以及对各种细菌群落和/或饲养策略的调查。这些结果导致在线测量 PHA 生产力的可能性。此外，它们允许对用于生物技术过程控制的 PHA 进行快速和廉价的量化/表征，以及对各种细菌群落和/或饲养策略的调查。