The adaptability of three Arctic microalgae to different low temperatures

Abstract

In order to study the adaptability of Arctic microalgae to different environmental temperatures, the growth curves and antioxidase system of three microalgae ( Skeletonema marinoi , Chlorella  sp. and Chlamydomonas sp.) that were separated from the Ny-Alesund, the high Arctic, at different low temperatures (0℃, 4℃ and 8℃) were determined. The result showed that the adaptability of the microalgae to temperatures depended on the species. The growth rate, SOD and CAT activities of Skeletonema marinoi were the highest at 4℃, but MDA content was the lowest. The growth rate and enzyme activity of Chlorella sp. were the highest at 8℃, while the lowest MDA content presented at 0℃. The growth of Chlamydomonas sp. at the different temperatures was not so significant, the lowest MDA content presented at 8℃. The change of antioxidase system also depended on species and temperatures. Three indexes of antioxidase system of Skeletonema marinoi between 0℃ and 4℃ showed extremely significant difference (p Skeletonema marinoi and Chlorella sp.between 0℃ and 8℃ showed significant difference (p Chlamydomonas sp. at the three temperatures differed insignificantly. In conclusion, the three microalgae had good adaptability to the three temperatures; their MDA content presented a low level, and had unique physiological mechanism to adapt to the environment with different low temperatures.