Raman spectroscopic analysis of Lactobacillus rhamnosus GG in response to dehydration reveals DNA conformation changes. Issue 4 (31st May 2016)

• Record Type: Journal Article
• Authors: Myintzu Hlaing, Mya; Wood, Bayden; McNaughton, Don; Ying, DanYan; Augustin, Mary Ann
• Is Part Of: Journal of biophotonics. Volume 10:Issue 4(2017)
• Page Start: 589
• Page End: 597
• Publication Date: 2016-05-31
• Subjects: Raman spectroscopy -- probiotics -- microencapsulation -- freeze drying; Photonics -- Periodicals; Optical materials -- Periodicals; Optics -- Periodicals; Medical instruments and apparatus -- Periodicals; 621.3605
• DOI: 10.1002/jbio.201600046
• Languages: English
• ISSNs: 1864-063X

Abstract

Abstract : Dehydration of bacterial cells elicits cellular stress responses in bacteria. Microencapsulation has been used to protect cells against the environmental stress. In this study, Confocal Raman Spectroscopy was used to examine DNA changes in the chemical composition of non‐encapsulated and microencapsulated Lactobacillus rhamnosus GG and the reversibility of these changes upon freeze drying and rehydration. The viability of cells upon freeze drying was also enumerated using culture methods and membrane integrity was measured using BacLight Live/Dead staining. Raman analyses show changes in the spectral features associated with various biochemical compounds, which are interpreted as the result of detrimental freeze drying effects on the bacterial cells. Specifically, analyses based on Principal Components Analysis (PCA) of Raman spectra, confirm that microencapsulation protects cells from environmental stress. The results also reveal a B‐ to A‐like DNA conformation change in dormant cells that provided insights into the extent of reversibility of this transition upon rehydration. The extent of this reversibility is less in non‐encapsulated than in microencapsulated cells. These findings indicate the potential application of Raman spectroscopy in rapid sensing of microbial dehydration stress responses. Abstract : Raman spectroscopy analysis on DNA conformation changes of microencapsulated bacterial cells in response to dehydration stress is presented.