ABSTRACT
The effect of nutrients deficiency (phosphorus, nitrogen and
sulphur) on growth, ultrastructure, β-carotene and total lipid contents of
the green alga Asteromonas gracilis has been examined. Algal cells were
cultured under conditions of nutrients deficiency. The maximum growth
rate and minimum generation time calculated on basis of chl. a were
0.032 and 21.9, respectively for control culture. The most changes in
ultrastructure of A. gracilis observed when cells were cultivated without
nitrogen source, the changes are in the structure of chloroplast, where the
degradation of thylakoids was observed and the grana structure of
thylakoids had almost disappeared as well as accumulation of starch
grains were easily detected. The total carbohydrates were decreased with
deficiency of phosphorus and sulphur, but increased in case of nitrogen
deficiency. On the other hand, the production of β-carotene and total
lipids was enhanced with phosphorus, nitrogen and sulphur deficiency.