Raman Spectrum of β-Carotene Using Laser Lines from Green (514.5 nm) to Near-Infrared (1064 nm): Implications for the Characterization of Conjugated Polyenes

Preliminary feasibility studies were performed using Stokes Raman scattering for compositional analysis of algae. Two algal species, Chlorella sorokiniana (UTEX #1230) and Neochloris oleoabundans (UTEX #1185), were chosen for this study. Both species were considered to be candidates for biofuel production. Raman signals due to storage lipids (specifically triglycerides) were clearly identified in the nitrogen-starved C. sorokiniana and N. oleoabundans, but not in their healthy counterparts. On the other hand, signals resulting from the carotenoids were found to be present in all of the samples. Composition mapping was conducted in which Raman spectra were acquired from a dense sequence of locations over a small region of interest. The spectra obtained for the mapping images were filtered for the wavelengths of characteristic peaks that correspond to components of interest (i.e., triglyceride or carotenoid). The locations of the components of interest could be identified by the high intensity areas in the composition maps. Finally, the time evolution of fluorescence background was observed while acquiring Raman signals from the algae. The time dependence of fluorescence background is characterized by a general power law decay interrupted by sudden high intensity fluorescence events. The decreasing trend is likely a result of photo-bleaching of cell pigments due to prolonged intense laser exposure, while the sudden high intensity fluorescence events are not understood.

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“…The optical image Figure 5. The Raman spectrum of carotenoid (Parker et al, 1999), chlorophyll (Chen et al, 2004), and triglyceride (cf. Fig.…”

Section: Chemical Composition Mappingmentioning

confidence: 99%

Micro‐Raman spectroscopy of algae: Composition analysis and fluorescence background behavior

Huang

Beal

Cai

et al. 2010

Biotech & Bioengineering

128

106

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“…The analysis of the image of the spectrographed cell allowed us to calculate the volume of algal lipid bodies in absolute units, to be used as a reference measurement. The overall sensitivity of the Raman analysis could be increased by several orders of magnitude using the resonance effect taking place when the excitation wavelength matches the absorption maximum, around 490 nm for β-carotene (Parker et al 1999). We have observed severalfold increase in sensitivity using pre-resonant excitation of β-carotene at 532 nm.…”

Section: Discussionmentioning

confidence: 81%

Raman microspectroscopy of algal lipid bodies: β-carotene quantification

et al. 2011

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Advanced optical instruments can serve for analysis and manipulation of individual living cells and their internal structures. We have used Raman microspectroscopic analysis for assessment of β-carotene concentration in algal lipid bodies (LBs) in vivo. Some algae contain β-carotene in high amounts in their LBs, including strains which are considered useful in biotechnology for lipid and pigment production. We have devised a simple method to measure the concentration of β-carotene in a mixture of algal storage lipids from the ratio of their Raman vibrations. This finding may allow fast acquisition of β-carotene concentration valuable, e.g., for Raman microspectroscopy assisted cell sorting for selection of the overproducing strains. Furthermore, we demonstrate that β-carotene concentration can be proportional to LB volume and light intensity during the cultivation. We combine optical manipulation and analysis on a microfluidic platform in order to achieve fast, effective, and non-invasive sorting based on the spectroscopic features of the individual living cells. The resultant apparatus could find its use in demanding biotechnological applications such as selection of rare natural mutants or artificially modified cells resulting from genetic manipulations.

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“…All these, except lutein, have 11 conjugated C=C bonds [66], and it has been demonstrated that their Raman spectra are close to that of the well documented β-carotene [67]. Carotenoids produce three characteristic peaks in the Raman spectrum [68][69][70][71][72][73]. Thus, β-carotene-a representative carotenoidexhibits two intense peaks at 1150 cm -1 and 1521 cm -1 arising from inplane stretching vibrations of C-C and C=C bonds respectively, and a third peak occurs at 1008 cm -1 , created by an in-plane rocking movement of methyl groups (CH 3 ) connected to the polyene chain backbone [74].…”

Section: Raman Spectroscopic Analysismentioning

confidence: 83%

Survival of Moss Reproductive Structures under Simulated Martian Environmental Conditions and Extreme Thermal Stress: Vibrational Spectroscopic Study and Astrobiological Implications

Gómez¹,

Estébanez²

2016

Astrobiol Outreach

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The principal goal of astrobiology is the search for extraterrestrial life forms. A key aspect is the study of the ability of different kinds of terrestrial organisms to support simulated extraterrestrial environmental conditions. Mosses are multicellular green plants, poorly studied from an astrobiological perspective. In this paper, we report experimental results obtained using two species of moss, which demonstrate that both the spores of the moss Funaria hygrometrica as well as the desiccated vegetative gametophyte shoots of the moss Tortella squarrosa (=Pleurochaete squarrosa) were capable of resisting Simulated Martian Environmental Conditions (SMEC): Mars simulated atmospheric composition 99.9% CO 2 , and 0.6% H 2 O with a pressure of 7 mbars, -73 º C and UV irradiation of 30 mW cm -2 in a wavelength range of 200-400 nm under a limited short time of exposition of 2 hours. After being exposed to SMEC and then transferred to an appropriate growth medium, the F. hygrometrica spores germinated, producing typical gametophyte protonemal cells and leafy shoots. Likewise, detached leaves from SMEC-exposed gametophyte shoots of T. squarrosa retained the ability to produce new protonemata and shoots under suitable growth conditions. Furthermore, we studied the tolerance of these moss structures to a thermal stress of 100 °C for 1 h; in both cases the spores and shoots were capable of resisting this heat treatment. Our study using FT-Raman and FT-IR vibrational spectroscopy demonstrated that neither spores nor shoots apparently suffered significant damage in their biomolecular makeup after being subject to these stress treatments. The implications of these findings for the search of life on Mars are discussed.

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Raman Spectrum of β-Carotene Using Laser Lines from Green (514.5 nm) to Near-Infrared (1064 nm): Implications for the Characterization of Conjugated Polyenes

Cited by 63 publications

References 26 publications

Micro‐Raman spectroscopy of algae: Composition analysis and fluorescence background behavior

Micro‐Raman spectroscopy of algae: Composition analysis and fluorescence background behavior

Raman microspectroscopy of algal lipid bodies: β-carotene quantification

Survival of Moss Reproductive Structures under Simulated Martian Environmental Conditions and Extreme Thermal Stress: Vibrational Spectroscopic Study and Astrobiological Implications

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