Raman spectroscopic identification of single yeast cells

Abstract

Eukaryotes (such as yeasts) and prokaryotes (such as bacteria) differ in size, molecular complexity, etc. By definition, eukaryotic cells store their DNA in a separate internal compartment, the so-called nucleus. Owing to this molecular compartmentalization, the identification of yeast cells by vibrational spectroscopy at a single-cell level is challenging. This contribution reports on first results of micro-Raman analysis together with a hierarchical cluster analysis allowing for an online identification method for yeast cells at a single-cell level. For the classification analysis, an average spectrum from 10 different measuring points within a single yeast cell was used to overcome the heterogeneity of the yeast cells.

Chemotaxonomic Raman Spectroscopy Investigation of Ascomycetes and Zygomycetes

“…[10][11][12][13][14] Although not shown here, we could find characteristic peaks from yeast using a confocal Raman spectrometer excited at 532 nm. Due to their smaller sizes and weak intensities without NP enhancements, we could not observe much stronger Raman signals from Saccharomyces cerevisiae using our DFM/Raman spectrometer.…”

“…8,9 Previous works on chemotaxonomic identification of fungi have mainly focused on unicellular yeasts. [10][11][12][13][14] In this work we have performed a Raman spectroscopic study of the two different fungal species: ascomycetes and zygomycetes in order to test rapid chemotaxonomic identification by means of a spectroscopic technique. Figure 1 shows our experimental set-up for the study of fungal species.…”

Synthesis of noble metal nanoparticles and their non-ordered superstructures

“…The effect of nanoparticle assembling on fungal mycelia could also be a useful tool for biochemical investigations, such as changing the impact of catalytically active nanoparticles on the metabolism of the microbiological systems, or concerning the fungal heavy-metal-accumulation effect. Other applications for silver-or gold-containing hybrids could be their use as templates for surfaceenhanced Raman spectroscopy (SERS), or even the identification of fungi using SERS (Rösch et al 2005;Szeghalmi et al 2007;Hering et al 2008). Other sensoric applications can be thought of by considering the plasmonic properties of the assembled nanoparticles or the conductivity of these systems, which still has to be determined.…”

Rapid bioparticle concentration and detection by combining a discharge driven vortex with surface enhanced Raman scattering

“…The characteristic peaks that are found in literature for S. cerevisiae were not prevalent. 13 Thus, Raman scattering alone cannot produce a distinct signal in the short scanning time of the concentrated packed mound.…”