Naslov
Marine microalgae under temperature and salinity stress – insight from AFM study

Autori
Mišić Radić, Tea ; Levak Zorinc, Maja ; Novosel, Nives ; Ivošević DeNardis, Nadica

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
4th Croatian Microscopy Congress with international participation : Book of Abstracts / Macan, Jelena ; Kovačević, Goran - Zagreb : Hrvatsko mikroskopijsko društvo ; Institut Ruđer Bošković, 2022, 24-24

ISBN
978-953-7941-41-3

Skup
4th Croatian Microscopy Congress (CMC 2022)

Mjesto i datum
Poreč, Hrvatska, 18.05.2022. - 20.05.2022

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Domaća recenzija

Ključne riječi
Marine microalgae ; Climate change ; Temperature ; Salinity

Sažetak
Global climate change is causing an increase in ocean temperature and models predict a possible decrease in salinity of the sea surface layer, which will inevitably affect microalgae. The objective of this study was to investigate the response of three microalgal species (C. closterium, D. tertiolecta, and T. suecica) to temperature and salinity stress in terms of growth, surface morphology, and physiological activity (extracellular polymeric substance (EPS) release). Structural details of the cell surface and the organization of released biopolymers were studied using high-resolution atomic force microscopy (AFM). Microalgae were exposed to single stressors, temperature fluctuations (12, 18, and 30 °C) and salinity fluctuations (9, 19, 27, and 38 ppt) under controlled laboratory conditions (Novosel et al. 2021, Novosel et al. 2022). Regarding cell growth, for D. tertiolecta and T. suecica, the fastest growth and shortest doubling time were obtained at 18 °C, which was considered a favourable temperature. For C. closterium, the fastest growth and shortest doubling time were obtained at 30 °C. All selected microalgae survived salinity from 9 ppt to 38 ppt and had the shortest doubling time and fastest growth at salinity of 9 ppt. Cell surface morphology did not show specific changes with temperature and salinity variations, but the change was observed in the size of microalgal species. Cells were smaller at higher temperatures and lower salinities. These results are consistent with the commonly known fact that phytoplankton cell size decreases with temperature and also with decreasing salinity. Aside from the change in cell size, loss of flagella was also observed in T. suecica cells under hyposaline conditions, which may indicate that the cells are transitioning to the cyst stage. Both temperature and salinity had effects on EPS release. A decrease in salinity, as well as a decrease in temperature, resulted in a significantly higher secretion of biopolymers, which allowed the stressed cells to survive under unfavourable conditions. The results of this study contribute to a better understanding of the effects of various environmental stressors on microalgae at the single cell level. Novosel N, Mišić Radić T, Zemla J, Lekka M, Čačković A, Kasum D, Legović T, Žutinić P, Gligora Udovič M, Ivošević DeNardis N (2021) Temperature-induced response in algal cell surface properties and behaviour: an experimental approach. J Appl Phycol 33:1-17 Novosel N, Mišić Radić T, Levak Zorinc M, Zemla J, Lekka M, Vrana I, Gašparović B, Horvat L, Kasum D, Legović T, Žutinić P, Gligora Udovič M, Ivošević DeNardis N (2022) Salinity induced chemical, mechanical and behavioral changes in algal cell cultures. J Appl Phycol, under review Acknowledgement - This work is supported by the Croatian Science Foundation Project "From algal cell surface properties to stress markers for aquatic ecosystems" (IP-2018–01-5840)

Izvorni jezik
Engleski

Znanstvena područja
Interdisciplinarne prirodne znanosti

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