Analyzing macromolecular composition of E. Coli O157:H7 using Raman-stable isotope probing

Heera Jayan; Hongbin Pu; Da-Wen Sun

doi:10.1016/j.saa.2022.121217

Analyzing macromolecular composition of E. Coli O157:H7 using Raman-stable isotope probing

Spectrochim Acta A Mol Biomol Spectrosc. 2022 Aug 5:276:121217. doi: 10.1016/j.saa.2022.121217. Epub 2022 Apr 1.

Authors

Heera Jayan¹, Hongbin Pu¹, Da-Wen Sun²

Affiliations

¹ School of Food Science and Engineering, South China University of Technology, Guangzhou 510641, China; Academy of Contemporary Food Engineering, South China University of Technology, Guangzhou Higher Education Mega Center, Guangzhou 510006, China; Engineering and Technological Research Centre of Guangdong Province on Intelligent Sensing and Process Control of Cold Chain Foods, & Guangdong Province Engineering Laboratory for Intelligent Cold Chain Logistics Equipment for Agricultural Products, Guangzhou Higher Education Mega Centre, Guangzhou 510006, China.
² School of Food Science and Engineering, South China University of Technology, Guangzhou 510641, China; Academy of Contemporary Food Engineering, South China University of Technology, Guangzhou Higher Education Mega Center, Guangzhou 510006, China; Engineering and Technological Research Centre of Guangdong Province on Intelligent Sensing and Process Control of Cold Chain Foods, & Guangdong Province Engineering Laboratory for Intelligent Cold Chain Logistics Equipment for Agricultural Products, Guangzhou Higher Education Mega Centre, Guangzhou 510006, China; Food Refrigeration and Computerized Food Technology (FRCFT), Agriculture and Food Science Centre, University College Dublin, National University of Ireland, Belfield, Dublin 4, Ireland. Electronic address: dawen.sun@ucd.ie.

PMID: 35427921
DOI: 10.1016/j.saa.2022.121217

Abstract

Metabolic dynamics of bacterial cells is needed for understanding the correlation between changes in environmental conditions and cell metabolic activity. In this study, Raman spectroscopy combined with deuterium labelling was used to analyze the metabolic activity of a single Escherichia coli O157:H7 cell. The incorporation of deuterium from heavy water into cellular biomolecules resulted in the formation of carbon-deuterium (CD) peaks in the Raman spectra, indicating the cell metabolic activity. The broad vibrational peaks corresponding to CD and CH peaks encompassed different specific shifts of macromolecules such as protein, lipids, and nucleic acid. The utilization of tryptophan and oleic acid by the cell as the sole carbon source led to changes in cell lipid composition, as indicated by new peaks in the second derivative spectra. Thus, the proposed method could semi-quantitatively determine total metabolic activity, macromolecule specific identification, and lipid and protein metabolism in a single cell.

Keywords: Carbon sources; Deuterium-labelling; Metabolic activity; Raman spectroscopy; Single-cell bacterium.

MeSH terms

Carbon* / metabolism
Deuterium
Escherichia coli* / metabolism
Lipids
Macromolecular Substances / metabolism

Substances

Lipids
Macromolecular Substances
Carbon
Deuterium