LOW TEMPERATURE PHASE TRANSITIONS IN GREEN MICROALGAE SUSPENSIONS

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00027006%3A_____%2F22%3A10175406" target="_blank" >RIV/00027006:_____/22:10175406 - isvavai.cz</a>

Result on the web

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DOI - Digital Object Identifier

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Result language

angličtina

Original language name

LOW TEMPERATURE PHASE TRANSITIONS IN GREEN MICROALGAE SUSPENSIONS

Original language description

Green microalgae Dunaliella salina is a promising source of carotene for the biotechnology industry. Cryopreservation is one of the best ways to preserve important strains of microalgae for a long time without losing their characteristic features. It is known that with a high degree of salinity, Dunaliella salina are capable of glycerol hypersynthesis. Glycerol, which accumulates in Dunaliella salina cells under stress, can act as a natural cryoprotectant. The aim of this research was to study low-temperature phase transitions in suspensions of green microalgae Dunaliella salina, which were cultivated on Ramaraj media with different content of sodium chloride. Phase transitions were studied by the method of differential scanning calorimetry at the heating stage (0.5 deg/min) after rapid cooling (~200 deg/min). Glass transition was registered in microalgae suspensions that were cultured in Ramaraj medium with 1.5 M, 3M and 4M of NaCl. This indicates an effective hypersynthesis of glycerol by Dunaliella salina microalgae. An intense exothermic peak was recorded at the heating stage at NaCl concentrations of 1.5 M and 3M (at -85.1oC and -86.8oC, respectively) almost immediately after completion of glass transition. This indicates low stability of the amorphous state in studied cell suspensions and the need for high heating rates to prevent crystallization processes from the amorphous state. The crystallization peak was not recorded in microalgae suspension with 4M of NaCl. The completion of crystallization of eutectic compositions was registered at the same temperature (-54oC) in the cell suspensions at all studied concentrations of NaCl. Two separate melting peaks were registered at 1.5 M of NaCl. They probably correspond to the melting of eutectic compositions and ice melting. An increase in NaCl concentration leads to a decrease in the melting point of ice and a lack of separation of the two melting peaks.

Czech name

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Czech description

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Type

O - Miscellaneous

CEP classification

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OECD FORD branch

40106 - Agronomy, plant breeding and plant protection; (Agricultural biotechnology to be 4.4)

Project

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Continuities

N - Vyzkumna aktivita podporovana z neverejnych zdroju

Publication year

2022

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů