Effect of low temperature storage conditions on the viability of microalgae Chlorococcum dissectum

Chlorococcum dissectum Korshikov, 1953 is a unicellular freshwater green alga capable of accumulating and depositing lipids in cells. Regardless of their origin and taxonomic classification, biotechnologically important microorganisms and cell lines are biological resources that are used to produce...

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Main Authors: K. Vozovyk, N. Shevchenko
Format: Article
Language:Russian
Published: V. N. Karazin Kharkiv National University 2022-12-01
Series:Вісник Харківського Національного Університету Імені В.Н. Каразіна: Серія Біологія
Subjects:
Online Access:https://periodicals.karazin.ua/biology/article/view/21230
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author K. Vozovyk
N. Shevchenko
author_facet K. Vozovyk
N. Shevchenko
author_sort K. Vozovyk
collection DOAJ
description Chlorococcum dissectum Korshikov, 1953 is a unicellular freshwater green alga capable of accumulating and depositing lipids in cells. Regardless of their origin and taxonomic classification, biotechnologically important microorganisms and cell lines are biological resources that are used to produce various products. The aim of the work was to determine the effect of low-temperature storage conditions on the alga viability. The temperatures used were as follows: –18, –40, –70, and –196°C. An ordinary household freezer was used to provide –18°C. Cooling to –40 and –70°C was carried out with uncontrolled cooling rates by placing the cryotubes directly into the freezers or using a Mr. Frosty freezing container, which provides a temperature decrease rate of 1 deg/min. Freezing to –196°C was carried out by direct immersion of cryotubes in liquid nitrogen and two-stage cooling at 1 and 20 deg/min to –40°C with subsequent transfer to a cryostorage. The viability of C. dissectum was determined by counting the colonies formed on BG-11 agarized nutrient medium. It was found that the cells completely lost their viability after freezing to –18°C and storage for two days. Cryopreservation to –196°C for all studied variants and uncontrolled cooling rate to –40 and –70°C, as well as further storage of such samples at these temperatures, led to significant or complete loss of their viability. Cooling in a Mr. Frosty freezer container to –40 and –70°C did not affect the ability of cells to grow. Moreover, storing C. dissectum at –40°C did not cause a significant loss of viability throughout the study period, and its storage at –70°C did not change the viability index at all. The obtained results showed that the controlled cooling and the use of freezers at –40°C and –70°C, respectively, are promising for medium-term and long-term storage of C. dissectum suspension culture. To increase the viability of samples after cooling to liquid nitrogen temperature, it is necessary to develop cryopreservation modes using cryoprotectants.
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spelling doaj.art-4c9f87bbc9334500ab369522a0de7f942023-04-17T12:43:09ZrusV. N. Karazin Kharkiv National UniversityВісник Харківського Національного Університету Імені В.Н. Каразіна: Серія Біологія2075-54572220-96972022-12-0139121910.26565/2075-5457-2022-39-221230Effect of low temperature storage conditions on the viability of microalgae Chlorococcum dissectumK. Vozovyk0N. Shevchenko1Institute for Problems of Cryobiology and Cryomedicine of the NAS of UkraineInstitute for Problems of Cryobiology and Cryomedicine of the NAS of UkraineChlorococcum dissectum Korshikov, 1953 is a unicellular freshwater green alga capable of accumulating and depositing lipids in cells. Regardless of their origin and taxonomic classification, biotechnologically important microorganisms and cell lines are biological resources that are used to produce various products. The aim of the work was to determine the effect of low-temperature storage conditions on the alga viability. The temperatures used were as follows: –18, –40, –70, and –196°C. An ordinary household freezer was used to provide –18°C. Cooling to –40 and –70°C was carried out with uncontrolled cooling rates by placing the cryotubes directly into the freezers or using a Mr. Frosty freezing container, which provides a temperature decrease rate of 1 deg/min. Freezing to –196°C was carried out by direct immersion of cryotubes in liquid nitrogen and two-stage cooling at 1 and 20 deg/min to –40°C with subsequent transfer to a cryostorage. The viability of C. dissectum was determined by counting the colonies formed on BG-11 agarized nutrient medium. It was found that the cells completely lost their viability after freezing to –18°C and storage for two days. Cryopreservation to –196°C for all studied variants and uncontrolled cooling rate to –40 and –70°C, as well as further storage of such samples at these temperatures, led to significant or complete loss of their viability. Cooling in a Mr. Frosty freezer container to –40 and –70°C did not affect the ability of cells to grow. Moreover, storing C. dissectum at –40°C did not cause a significant loss of viability throughout the study period, and its storage at –70°C did not change the viability index at all. The obtained results showed that the controlled cooling and the use of freezers at –40°C and –70°C, respectively, are promising for medium-term and long-term storage of C. dissectum suspension culture. To increase the viability of samples after cooling to liquid nitrogen temperature, it is necessary to develop cryopreservation modes using cryoprotectants.https://periodicals.karazin.ua/biology/article/view/21230microalgae, c. dissectum, viability, low-temperature storage, cryopreservation
spellingShingle K. Vozovyk
N. Shevchenko
Effect of low temperature storage conditions on the viability of microalgae Chlorococcum dissectum
Вісник Харківського Національного Університету Імені В.Н. Каразіна: Серія Біологія
microalgae, c. dissectum, viability, low-temperature storage, cryopreservation
title Effect of low temperature storage conditions on the viability of microalgae Chlorococcum dissectum
title_full Effect of low temperature storage conditions on the viability of microalgae Chlorococcum dissectum
title_fullStr Effect of low temperature storage conditions on the viability of microalgae Chlorococcum dissectum
title_full_unstemmed Effect of low temperature storage conditions on the viability of microalgae Chlorococcum dissectum
title_short Effect of low temperature storage conditions on the viability of microalgae Chlorococcum dissectum
title_sort effect of low temperature storage conditions on the viability of microalgae chlorococcum dissectum
topic microalgae, c. dissectum, viability, low-temperature storage, cryopreservation
url https://periodicals.karazin.ua/biology/article/view/21230
work_keys_str_mv AT kvozovyk effectoflowtemperaturestorageconditionsontheviabilityofmicroalgaechlorococcumdissectum
AT nshevchenko effectoflowtemperaturestorageconditionsontheviabilityofmicroalgaechlorococcumdissectum