PITFALLS OF MEASUREMENTS CYANOBACTERIAL VIABILITY AFTER STRESS EXPOSURE VIA FLOW CYTOMETRY

prezentace, poster

angličtina

Cyanobacteria are ecologically important phototrophic bacteria capable of oxygenic photosynthesis. Cyanobacteria played a key role in planet evolution and are responsible for the oxygenic atmosphere. Cyanobacteria synthesize many interesting metabolites such as glycogen, lipids, various pigments or polyhydroxyalkanoates (PHA). PHAs are biodegradable biopolymers with similar properties as petrochemical plastics and they occur as intracellular granules. Numerous prokaryotes including cyanobacteria use PHA primarily as a storage of carbon and energy in the form of intracellular granules, secondary PHB raises the fitness of bacteria because it helps the bacteria to survive stress conditions e.g., osmotic stress, UV radiation or freezing. As PHAs are economically interesting metabolites PHA production employing cyanobacteria seems to be the promising way of CO2 valorisation. Nevertheless, a reliable technique for measurement of the viability of employed cultures is an important tool to monitor the biotechnological process. In this study, we sought a reliable and suitable probe for our cyanobacterial cultures capable of PHA accumulation. The biggest difference from heterotrophic bacteria is that cyanobacteria contain a wide spectrum of various pigments, from chlorophylls, through carotenoids to phycocyanines or phycobiliproteins and the pigmentation and even resulting autofluorescence changes during cultivation. Therefore, numerous commonly used probes are due to the presence of pigments inapplicable. Moreover, cyanobacterial strain Synechocystis possess an extra layer on the surface, called S-layer, which could make staining of cells difficult. For that purpose, we were looking for a probe(s) that does fit with cyanobacteria, stains dead cells, is suitable for flow cytometry, and does fit with our cyanobacteria cells at various physiological states and flow cytometer. Together with the probe, also troubleshooting of sample preparation was necessary.

flow cytometry, cyanobacteria, viability

ŠEDRLOVÁ, Z.; SLANINOVÁ, E.; OBRUČA, S.

6. 9. 2023

AMCA, spol. s. r. o.

Praha 2023

139

139

155

https://www.conference.csac.cz/Amca-CSAC/media/content/2023/docs/Book_of_abstracts_CSAC_2023.pdf