Simultaneous Raman and Infrared Spectroscopy of Stable Isotope Labelled <i>Escherichia coli</i>
We report the use of a novel technology based on optical photothermal infrared (O-PTIR) spectroscopy for obtaining simultaneous infrared and Raman spectra from the same location of the sample allowing us to study bacterial metabolism by monitoring the incorporation of <sup>13</sup>C- and...
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| Format: | Article |
| Language: | English |
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MDPI AG
2022-05-01
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| Series: | Sensors |
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| Online Access: | https://www.mdpi.com/1424-8220/22/10/3928 |
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| author | Cassio Lima Howbeer Muhamadali Royston Goodacre |
| author_facet | Cassio Lima Howbeer Muhamadali Royston Goodacre |
| author_sort | Cassio Lima |
| collection | DOAJ |
| description | We report the use of a novel technology based on optical photothermal infrared (O-PTIR) spectroscopy for obtaining simultaneous infrared and Raman spectra from the same location of the sample allowing us to study bacterial metabolism by monitoring the incorporation of <sup>13</sup>C- and <sup>15</sup>N-labeled compounds. Infrared data obtained from bulk populations and single cells via O-PTIR spectroscopy were compared to conventional Fourier transform infrared (FTIR) spectroscopy in order to evaluate the reproducibility of the results achieved by all three approaches. Raman spectra acquired were concomitant with infrared data from bulk populations as well as infrared spectra collected from single cells, and were subjected to principal component analysis in order to evaluate any specific separation resulting from the isotopic incorporation. Similar clustering patterns were observed in infrared data acquired from single cells via O-PTIR spectroscopy as well as from bulk populations via FTIR and O-PTIR spectroscopies, indicating full incorporation of heavy isotopes by the bacteria. Satisfactory discrimination between unlabeled (<i>viz</i>. <sup>12</sup>C<sup>14</sup>N), <sup>13</sup>C<sup>14</sup>N- and <sup>13</sup>C<sup>15</sup>N-labeled bacteria was also obtained using Raman spectra from bulk populations. In this report, we also discuss the limitations of O-PTIR technology to acquire Raman data from single bacterial cells (with typical dimensions of 1 × 2 µm) as well as spectral artifacts induced by thermal damage when analyzing very small amounts of biomass (a bacterium tipically weighs ~ 1 pg). |
| first_indexed | 2024-03-10T01:52:05Z |
| format | Article |
| id | doaj.art-85d6bcec25614073893e2d2eb952af49 |
| institution | Directory Open Access Journal |
| issn | 1424-8220 |
| language | English |
| last_indexed | 2024-03-10T01:52:05Z |
| publishDate | 2022-05-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Sensors |
| spelling | doaj.art-85d6bcec25614073893e2d2eb952af492023-11-23T13:03:40ZengMDPI AGSensors1424-82202022-05-012210392810.3390/s22103928Simultaneous Raman and Infrared Spectroscopy of Stable Isotope Labelled <i>Escherichia coli</i>Cassio Lima0Howbeer Muhamadali1Royston Goodacre2Centre for Metabolomics Research, Department of Biochemistry and Systems Biology, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool L69 7ZB, UKCentre for Metabolomics Research, Department of Biochemistry and Systems Biology, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool L69 7ZB, UKCentre for Metabolomics Research, Department of Biochemistry and Systems Biology, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool L69 7ZB, UKWe report the use of a novel technology based on optical photothermal infrared (O-PTIR) spectroscopy for obtaining simultaneous infrared and Raman spectra from the same location of the sample allowing us to study bacterial metabolism by monitoring the incorporation of <sup>13</sup>C- and <sup>15</sup>N-labeled compounds. Infrared data obtained from bulk populations and single cells via O-PTIR spectroscopy were compared to conventional Fourier transform infrared (FTIR) spectroscopy in order to evaluate the reproducibility of the results achieved by all three approaches. Raman spectra acquired were concomitant with infrared data from bulk populations as well as infrared spectra collected from single cells, and were subjected to principal component analysis in order to evaluate any specific separation resulting from the isotopic incorporation. Similar clustering patterns were observed in infrared data acquired from single cells via O-PTIR spectroscopy as well as from bulk populations via FTIR and O-PTIR spectroscopies, indicating full incorporation of heavy isotopes by the bacteria. Satisfactory discrimination between unlabeled (<i>viz</i>. <sup>12</sup>C<sup>14</sup>N), <sup>13</sup>C<sup>14</sup>N- and <sup>13</sup>C<sup>15</sup>N-labeled bacteria was also obtained using Raman spectra from bulk populations. In this report, we also discuss the limitations of O-PTIR technology to acquire Raman data from single bacterial cells (with typical dimensions of 1 × 2 µm) as well as spectral artifacts induced by thermal damage when analyzing very small amounts of biomass (a bacterium tipically weighs ~ 1 pg).https://www.mdpi.com/1424-8220/22/10/3928RamanO-PTIRbacteriastable isotope labelingspectroscopy |
| spellingShingle | Cassio Lima Howbeer Muhamadali Royston Goodacre Simultaneous Raman and Infrared Spectroscopy of Stable Isotope Labelled <i>Escherichia coli</i> Sensors Raman O-PTIR bacteria stable isotope labeling spectroscopy |
| title | Simultaneous Raman and Infrared Spectroscopy of Stable Isotope Labelled <i>Escherichia coli</i> |
| title_full | Simultaneous Raman and Infrared Spectroscopy of Stable Isotope Labelled <i>Escherichia coli</i> |
| title_fullStr | Simultaneous Raman and Infrared Spectroscopy of Stable Isotope Labelled <i>Escherichia coli</i> |
| title_full_unstemmed | Simultaneous Raman and Infrared Spectroscopy of Stable Isotope Labelled <i>Escherichia coli</i> |
| title_short | Simultaneous Raman and Infrared Spectroscopy of Stable Isotope Labelled <i>Escherichia coli</i> |
| title_sort | simultaneous raman and infrared spectroscopy of stable isotope labelled i escherichia coli i |
| topic | Raman O-PTIR bacteria stable isotope labeling spectroscopy |
| url | https://www.mdpi.com/1424-8220/22/10/3928 |
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