| AVS 60th International Symposium and Exhibition | |
| Biomaterial Interfaces | Monday Sessions |
| Session BI+AI+BA+IS-MoA |
| Session: | Biofouling |
| Presenter: | M.M. Hlaing, Swinburne University of Technology, Australia |
| Authors: | M.M. Hlaing, Swinburne University of Technology, Australia M. Dunn, Swinburne University of Technology, Australia S.M. McArthur, Swinburne University of Technology, Australia P.R. Stoddart, Swinburne University of Technology, Australia |
| Correspondent: | Click to Email |
The characterisation and identification of individual bacteria using Raman spectroscopy can aid in rapid, in situ microbiological diagnosis and hence timely, appropriate treatment and control measures [1, 2]. Appropriate sample preparation methods and experimental conditions are crucial to avoid some potential difficulties in analysing the information-rich Raman spectra from bacterial cells. In this study, the Raman spectra of fresh and stored samples of bacterial isolates (Escherichia coli) were analysed to determine any variations caused by sample processing. Analysis based on principal components suggests that different methods of sample preparation and storage affect the spectral components associated with different biochemical compounds in bacterial cells. The effect of long term storage in glycerol stock at freezing temperatures on the Raman spectrum of cells from the early exponential phase was observed in this study and found to modify the bacteria cells. Furthermore, the presence of extracellular polymeric substance (EPS) matrix around bacterial cells at later stages of the growth cycle provide higher resistance to environmental stress compared with other phases. Based on these results, a specific experimental protocol has been developed in order to obtain interpretable, comparable and reliable Raman data from bacterial samples.
Keywords: Raman spectroscopy; Bacterial identification; Sample preparation.
References
[1] W. E. Huang, R. I. Griffiths. Anal. Chem. 2004, 76(15): 4452-4458.
[2] T. J. Moritz, S. T. Douglas. J. Clin. Microbiol. 2010, 48(11): 4287-4290.