عنوان مقاله [English]
In this experiment, we studied the effects of ionic and nonionic iso osmotic and defferent NaCl solutions on morphology and proliferation of biflagellate, halophilic micro alga, Dunaliella salina.
Osmotic pressure of 2.5%, 7.5% and 12.5% NaCl solutions were selected for preparing of iso osmotic solution (glycerol, ethylene glycol (EG), poly ethylene glycol (PEG), sucrose, mannitol and NaCl). Materials were added to Johnson medium.
Dunaliella salina was obtained from Biology Department of Islamic Azad University, Unit of Gorgan. Growth condition was fixed in all experiments (litght, 5000 Lux, aeration, 1 hour daily, temperature, 255oC,).
The microscopic results showed that Dunaliella salina not only can not proliferate in the iso osmotic solutions, without NaCl but also misses the mobility and finally dies after defferent times, in different solutions. Neverthless in the salt solutions Dualiella salina can proliferate and shows normal morphology and mobility. Based on results of this experiment, optimum proliferation occurred in 7.5% NaCl.
Cell fresh wight wa less in 7.5% NaCl (probably because of more proliferation in this treatment). Chlorophyll a, Chlorophyll b, and -Carotene showed significant increases in 7.5% NaCl. It seems that Dunaliella salina can not adopt with nonionic osmotic stress. Lack of Na+, can destroy ion homeostasis and the power of resistance. Decrease or increase Na+ from optimum concentration is the stress that effects on activities.