TY  - JOUR
AU  - Moudříková, Šárka
AU  - Nedbal, Ladislav
AU  - Solovchenko, Alexei
AU  - Mojzeš, Peter
TI  - Raman microscopy shows that nitrogen-rich cellular inclusions in microalgae are microcrystalline guanine
JO  - Algal Research
VL  - 23
SN  - 2211-9264
CY  - Amsterdam [u.a.]
PB  - Elsevier
M1  - FZJ-2017-02020
SP  - 216 - 222
PY  - 2017
AB  - Microalgal cells possess a vast diversity of subcellular structures and cytoplasmic inclusions differing in theirmorphology, functionality, and composition, some of them giving rise to distinct Raman spectral signaturesallowing their identification, localization, and visualization in situ. Here,we showthat certain Raman features observedin Raman spectra of microalgae can be unambiguously attributed to guanine microcrystals because theyare clearly distinct from Raman fingerprints of closely related purine species. Using confocal Raman microscopy,we have localized crystalline guanine as a part of cellular inclusions in the chlorophyte Desmodesmus quadricaudaand in the eustigmatophyte Trachydiscus minutus. Wepropose that this finding also explains the chemical natureof similar nitrogen-rich crystalline structures recently documented in a number of other chlorophyte species byenergy-dispersive X-ray spectroscopy. To the best of our knowledge, this is the first Raman microscopy-based directevidence of the presence of guanine microcrystalline inclusions within microalgal cells. We tentatively proposethat the crystalline guanine serves as a very compact, long-termdepot of nitrogen in microalgae. Simplicityof specimen preparation requiring no fixation, labeling, or staining of the cells predetermines Raman microscopyas a method of choice for more advanced studies of the physiological role of guanine particles, as well as othercrystalline inclusions in situ within intact cells.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000397462700024
DO  - DOI:10.1016/j.algal.2017.02.009
UR  - https://juser.fz-juelich.de/record/827998
ER  -