Comparison of some freshwater green algae conservation using the of freeze-drying and cryopreservation methods

This study was conducted to evaluate the possible conservation of freshwater green algae using the freeze-drying and cryopreservation methods and comparative of their growth potential. Three experimental algae including Chlamydomonas moewusii، Scenedesmus obliquus، and Chlorococcum olefaciens were cultured for 20 days in 6 Erlenmeyer flasks after preparation of Zinder growth medium. Each algal strain was preserved according to freeze-drying and cryopreservation protocols with 9 replications (3 replications for the days of 1، 5، and 10). Algae were then re-incubated and their growth was evaluated in 1، 5، and 10 days after preservation. Another 9 Erlenmeyer flasks for each algal species were prepared as control treatment by adding the respective growth medium to consider the growth of algae in the same days with similar scale. Highest growth of all experimental algae was obtained after 10 days which was significantly higher than the corresponding control treatments (p<0. 05). However، no significant difference was observed in the growth of Scenedesmus obliquus and and Chlorococcum olefaciens after freeze-drying and cryopreservation (p>0. 05). Results of the present study illustrated that both preservative methods are suitable for maintenance of experimental algae، although freeze-drying provided better results in Chlamydomonas moewusii.