Characterization of oil-producing microalgae using Raman spectroscopy

Abstract

Raman spectroscopy offers a powerful alternative analytical method for the detection and identification of lipids/oil in biological samples, such as algae and fish. Recent research in the authors' groups, and experimental data only very recently published by us and a few other groups suggest that Raman spectroscopy can be exploited in instances where fast and accurate determination of the iodine value (associated with the degree of lipid unsaturation) is required. Here the current status of Raman spectroscopy applications on algae is reviewed, and particular attention is given to the efforts of identifying and selecting oil-rich algal strains for the potential mass production of commercial biofuels and for utilization in the food industry.

Study of carotenoids in cyanobacteria by Raman spectroscopy

“…Carotenoids are a very special family consisting over 400 conjugated polyenes with C40 substituted and unsubstituted/unsaturated carbon-carbon chains and, jointly with chlorophyll compounds, are responsible for radiation absorptions, mainly in the visible region of the electromagnetic spectrum [33,[50][51][52][53]. The Raman spectra profile of these type of polyunsaturated chain present three characteristic bands located at specific wavenumbers, in the region between 1600-1000 cm -1 which are definitive data for those pigments characterization by Raman spectroscopy [38,39,43,54,55]. These bands are specifically located at ~ 1500 (v 1 ), 1160 (v 2 ) and 1000 cm -1 (ρ 3 ), assigned respectively to (C=C) and (C-C) stretching and (C-CH 3 ) deformation modes.…”

Dengue blood analysis by Raman spectroscopy

“…It is a spectroscopic technique used to study vibrational, rotational, and other low fre quency modes in a system and the mechanism of bind ing of human serum albumin to molecular probe fluo rescein [10]. It is one of the most informative methods for the investigation and analysis of proteins mole cules, blood constituents binding of nanomarkers of fluorescein family to HSA secondary Structure at dif ferent values of pH, amount of chemical information, detection and identification of lipids/oil in biological samples, such as algae and fish, and for the mechanism of denaturation HAS under action of a cationic deter gent C ethyltrimethyl ammonium bromide (CTAB) [11][12][13][14]. Optical methods are successfully employed for the studies of biological objects, because all macro molecules are similar in their chemical structure but differ in sizes and structure [15].…”

Raman microspectroscopy of algal lipid bodies: β-carotene quantification

“…We believe that Raman microspectroscopy has the potential to become fast and versatile tool for applications in lipid and pigment biotechnology, engineering, and industry. The usefulness of Raman spectroscopic analysis especially when combined with optical trap was already demonstrated in experiments with algae and other microorganisms (Xie et al 2004;Heraud et al 2007;Huang et al 2010;Wu et al 2011;Samek et al 2011). With combination of Raman spectroscopy, optical trapping, and microfluidic system, one can realize a high-throughput label-free and non-invasive automated cell sorting based on spectroscopic features of individual living cells, which could find its use in challenging biotechnological applications such as the selection of rare natural mutants or artificially modified cells resulting from genetic manipulations.…”