The conjugating green alga Zygnema sp. (Zygnematophyceae) from the Arctic shows high frost tolerance in mature cells (pre-akinetes).

ABSTRACT: Green algae of the genus Zygnema form extensive mats and produce large amounts of biomass in shallow freshwater habitats. Environmental stresses including freezing may perturb these mats, which usually have only annual character. To estimate the limits of survival at subzero temperatures, freezing resistance of young Zygnema sp. (strain MP2011Skan) cells and pre-akinetes was investigated. Young, 2-week-old cultures were exposed to temperatures of 0 to - 14 °C at 2-K steps, whereas 8-month-old cultures were frozen from - 10 to - 70 °C at 10-K intervals. Cell viability after freezing was determined by 0.1% auramine O vital fluorescence staining and measurements of the effective quantum yield of photosystem II (Ф_PSII). At - 8 °C, the young vegetative cells were unable to recover fr

SUBMITTER: Trumhova K 

PROVIDER: S-EPMC6820810 | biostudies-literature | 2019 Nov

REPOSITORIES: biostudies-literature