Raman microspectroscopy of algal lipid bodies: β-carotene quantification
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.
KeywordsRaman microspectroscopy Microalgae Trachydiscus minutus Biotechnology Carotenoids
These activities were partially supported by the Czech Ministry of Industry and Trade (FR-TI1/433) and the Ministry of Education, Youth, and Sports of the Czech Republic, together with the European Commission (ALISI No. CZ.1.05/2.1.00/01.0017)
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