Monitoring and rapid quantification of  total carotenoids in Rhodotorula glutinis cells using laser tweezers Raman spectroscopy

Abstract

Rhodotorula glutinis is known to accumulate large amounts of carotenoids under certain culture conditions, which have very important industrial applications. So far, the molecular mechanism of regulating carotenogenesis is still not well understood. To better understand the carotenogenesis process, it requires methods that can detect carotenogenesis rapidly and reliably in single live cells. In this paper, a method based on laser tweezers Raman spectroscopy (LTRS) was developed to directly detect carotenoids, as well as other important biological molecules in single live R. glutinis cells. The data showed that the accumulation of carotenoids and lipids occurred mainly in the late exponential and stationary phases when the cell growth was inhibited by nutrient limitation. Meanwhile, the carotenoid concentration changed together with the concentration of nucleic acids, which increased in the first phase and decreased in the last phase of the culture. These data demonstrate that LTRS is a rapid, convenient, and reliable method to study the carotenogenesis process in vivo.

Nature, Source and Function of Pigments in Tardigrades: In Vivo Raman Imaging of Carotenoids in Echiniscus blumi

“…a concentration permitting high stress compatible with high survival) and then, by exploiting the correlation between the concentration of carotenoids and the intensity of their Raman signal [18], [24], [25], to perform a semi-quantitative analysis of these pigments in living tardigrades before and after H 2 O 2 exposure.…”

Structural and Spatial Analysis of Carotenoids in a Single Cell Monitored by Raman Spectroscopy

“…the LtRSbased analysis of the kinetics of total carotenoid accumulation inside individual Rhodotorula glutinis cells demonstrated a significant variation of the carotenoid level in the studied population of 100 cells, particularly for certain growth phases. this variation indicates for high cellular heterogeneity in the studied cellular population, and provide for better understanding of carotenogenesis not only in the bulk sample, but for individual cells [20].…”

“…Laser tweezers Raman spectroscopy (LtRS) was applied to study the carotenogenesis process in a single live cell of yeast Rhodotorula glutinis [20]. the LtRSbased analysis of the kinetics of total carotenoid accumulation inside individual Rhodotorula glutinis cells demonstrated a significant variation of the carotenoid level in the studied population of 100 cells, particularly for certain growth phases.…”

“…Chemometric methods are often used to recognize between synthesized carotenoids of similar vibrational signature [19], distinguish cells grown in different environmental conditions [13][14][15], and find differences between carotenoid composition in different species [15]. Possibility of the application of Raman microspectroscopy to study a single cell rather than bulk sample is of high importance due to observed heterogeneity of cellular populations in unicellular species [20,21].…”

Raman tweezers in microfluidic systems for analysis and sorting of living cells

“…In all the cases we have measured Raman spectra of individual living microalgal cells. Other researchers have used ratios of Raman spectral signatures of mixtures of artificial and biological nature to identify different carotenoids [4,5] , to measure the relative abundance of cis and trans isomers of lipids [6] , their phase transition temperature [7] , positional isomerization [8] , oxidation [9] as well as unsaturation [10][11][12] . Some researchers give precise Raman analyses of pure lipids [13][14][15] , carbohydrates [16] , pigments [17,18] , and various other pure biologically relevant substances.…”