Probing the Influence of the Environment on Microalgae Using Infrared and Raman Spectroscopy

摘要

Since 2000, a diverse range of methods employing vibrational spectroscopy have been developed to study microalgae, mainly focused on probing the effects of environmental change on these ecologically important organisms. These include: FTIR microspectroscopy and Attenuated Total Reflectance (ATR) FTIR spectroscopy of ex vivo samples; synchrotron FTIR microspectroscopy of in vivo samples; Raman microspectroscopy of living algal cells; and in vivo Raman spectroscopy of algal samples using acoustic levitation. It has been demonstrated that ex vivo FTIR spectroscopic analysis can track macromolecular changes in microalgae as accurately as conventional methods, whilst requiring much less biological material for the analyses. This work has been extended, through the use of synchrotron sources of IR light, to the measurement of changes in macromolecular composition in living algal cells at the intracellular level. It has also been shown that Raman spectroscopy can detect changes in pigments such as chlorophyll α and β-carotene in living microalgal cells, caused by changing light and nutrient conditions, thus providing complementary information on the same processes probed by FTIR spectroscopy. Given the portability of Raman systems using acoustic levitation of samples, it may be possible, in the near future, to extend the laboratory studies to the determination of nutrient status of living algal cells in the field.