Abstract Self-adherent bacterial communities are embedded into biofilms, these densely packed and distinctive microbial matrices are surrounded by extracellular polymeric substances (EPS). The growth surface of bacteria, environmental conditions and harvesting methods may alter the biochemical composition of secreted EPS and the selection of EPS isolation method has critical role on analysis. In the present study, EPS produced by various strains were extracted using two extraction methods including liquid (broth) or solid (agar) media. The biomolecular content of resulting extracts were investigated for comparative analysis of different EPS isolation methods. EPS composition of each strain was analyzed by Fourier transform infrared spectroscopy (FTIR), a non-common technique for foodborne pathogen researches. According to the FTIR analysis results of the samples extracted by liquid media technique, some additional peaks were observed at 1397 cm−1 and 1230 cm−1. These peaks cannot be observed for solid media samples, two of the molecular fingerprints were disappeared and the protein content have found decreased. Similar results obtained from conventional protein assay (Bradford), 8 out of 10 samples of liquid extraction method were also shown to be significantly higher in comparison solid extraction method (p

中文翻译：

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傅里叶变换红外光谱法测定细菌细胞外聚合物的蛋白质谱

摘要 自粘附细菌群落嵌入生物膜中，这些密集且独特的微生物基质被细胞外聚合物 (EPS) 包围。细菌的生长表面、环境条件和收获方法可能会改变分泌型 EPS 的生化成分，EPS 分离方法的选择对分析至关重要。在本研究中，使用两种提取方法提取各种菌株产生的 EPS，包括液体（肉汤）或固体（琼脂）培养基。研究所得提取物的生物分子含量，以对不同的 EPS 分离方法进行比较分析。通过傅里叶变换红外光谱 (FTIR) 分析每个菌株的 EPS 成分，这是一种用于食源性病原体研究的非常用技术。根据液体介质技术提取的样品的 FTIR 分析结果，在 1397 cm-1 和 1230 cm-1 处观察到一些额外的峰。对于固体培养基样品，无法观察到这些峰，两个分子指纹消失了，并且发现蛋白质含量降低。从常规蛋白质测定 (Bradford) 获得的类似结果，液体提取方法的 10 个样品中的 8 个也显示在比较固体提取方法中显着更高 (p