Employing optical spectroscopy we have performed a comparative study of the dielectric response of extracellular matrix and filaments of electrogenic bacteria Shewanella oneidensis MR-1, cytochrome c, and bovine serum albumin. Combining infrared transmission measurements on thin layers with data of the terahertz spectra, we obtain the dielectric permittivity and AC conductivity spectra of the materials in a broad frequency band from a few cm−1 up to 7000 cm−1 in the temperature range from 5 to 300 K. Strong absorption bands are observed in the three materials that cover the range from 10 to 300 cm−1 and mainly determine the terahertz absorption. When cooled down to liquid helium temperatures, the bands in Shewanella oneidensis MR-1 and cytochrome c reveal a distinct fine structure. In all three materials, we identify the presence of liquid bound water in the form of librational and translational absorption bands at ≈ 200 and ≈ 600 cm−1, respectively. The sharp excitations seen above 1000 cm−1 are assigned to intramolecular vibrations.

中文翻译：

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希瓦氏菌 MR-1 细胞外基质的太赫兹红外光谱

我们利用光谱法对产电细菌 Shewanella oneidensis MR-1、细胞色素 c 和牛血清白蛋白的细胞外基质和细丝的介电响应进行了比较研究。将薄层上的红外透射测量与太赫兹光谱数据相结合，我们获得了在 5 至 5 ℃的温度范围内，材料在几 cm−1 至 7000 cm−1 的宽频带内的介电常数和交流电导率谱。 300 K。在三种材料中观察到强吸收带，覆盖范围从10到300 cm−1，主要决定太赫兹吸收。当冷却至液氦温度时，Shewanella oneidensis MR-1 和细胞色素 c 中的条带显示出独特的精细结构。在所有三种材料中，我们分别在约 200 和约 600 cm−1 处以解放和平移吸收带的形式识别出液态结合水的存在。1000 cm−1 以上的尖锐激发归因于分子内振动。