The use of FTIR spectroscopy to assess quantitative changes in the biochemical composition of microalgae

Abstract

A mid-infrared spectroscopic method was developed for the simultaneous and quantitative determination of total protein, carbohydrate and lipid contents of microalgal cells. Based on a chemometric approach, measured FTIR (Fourier transform infrared) spectra from algal cells were reconstructed by a partial least square algorithm, using the spectra of the reference substances to determine their relative contribution to the overall cell spectrum. From this specific absorption, absolute macromolecular cell composition [pg cell(-1)] can be calculated using calibration curves, which have been validated by independent biochemical methods. The future potential of this method for photosynthesis research is shown by its application to follow time-resolved changes in the cellular composition of microalgae during an illumination period of several hours. We show how the macromolecular composition can be investigated by FTIR spectroscopy methods. This can substantially increase the efficiency of screening processes like bioreactor monitoring and may be beneficial in metabolic engineering of algal cells.

Effect of Temperature and Nutrient Limitation on the Growth and Lipid Content of Three Selected Microalgae (<i>Dunaliella tertiolecta</i>, <i>Nannochloropsis</i> sp. and <i>Scenedesmus</i> sp.) for Biodiesel Production

“…The samples were then desiccated under vacuum for overnight. The dried cellular deposit on the CFR Low-e microscope slide was placed on the FTIR microscope stage for spectral acquisition Giordano et al, 2001;Wagner et al, 2010). FTIR spectra collected using FTIR spectrometer (Varian 7000, FTIR Stingray Imaging Series) coupled to an infrared microscope (Varian 6000 UMA FTIR microscope) and equipped with a mercury-cadmium-telluride detector cooled with liquid N 2 .…”

“…The extract was evaporated in a water bath (50℃) using a rotary evaporator (Buchi, Switzerland) to remove solvents and weight the flask for determining lipid content. The lipid extraction followed the protocol reported by Guckert et al (1988); Wagner et al (2010) and Lee et al (1998). (Figure 1).…”

“…FTIR spectroscopy can be used to monitor the biochemical content of phytoplankton cells in very short time intervals of less than one hour (Wagner et al, 2010). In this study, FTIR spectroscopy was used to determine relative neutral lipid content in three selected microalgae (Dunaliella tertiolecta, Scenedesmus sp.…”

Rapid method for simultaneous discrimination of microalgae and determination on biochemical composition based on vibrational spectroscopy

“…Она содержит полосы, связанные с РО 2 -симметричным растяжением фосфолипидов и спиральной основы ДНК, а также с вкладом неродственного неорганического Si-O-валентного колебания при 1075 см -1 . Сложно скомбинировать разрешение углеводной C-O-растягивающей колебательной связи, однако в нашем исследовании было обнаружено, что ярко выраженный характерный пик при 1056 см -1 хорошо коррелирует с содержанием углеводов в образцах биомассы (Wagner et al, 2010).…”

Taxon-specific responses of Southern Ocean diatoms to Fe enrichment revealed by synchrotron radiation FTIR microspectroscopy

“…SR-FTIR microspectroscopy is a semi-quantitative technique whereby changes in macromolecular absorbance are proportional to changes in the concentrations of those macromolecules. According to the Beer-Lambert law, absorbance is proportional to the path length through the sample and the concentration of light-absorbing molecules, as has been validated for diatoms and other microalgae (Heraud et al, 2007;Jungandreas et al, 2012;Wagner et al, 2010). Given that no independent data were available for the calibration of the SR-FTIR spectral data, we do not report changes in macromolecules in absolute units, however a doubling of absorbance at a particular wavenumber, for example, is indicative of a doubling in concentration of the macromolecules which absorb at those wavenumbers, given adherence to the Beer-Lambert law.…”