Evaluation of morphological variation and biomass growth of Nostoc commune under laboratory conditions.

: Nostoc commune is a blue green alga used for health food and herbal medicine due to its nutritional values and antioxidant properties. However, wild type N. commune has been decreasing in quantity as a result of ever-growing market demand and environmental pollution. Therefore, artificial culture of N. commune is important as it can bring great social and economic benefits. In this article, N. commune was cultured in BG11 medium, under which condition morphological variation and biomass growth of N. commune were investigated. Results indicated that concentration, fresh weight and dry weight of the colony increased fastest at 40 rpm from the 1st day to 14th day and the fresh and dry weight increased as the culturing time was prolonged, and reached 27.22 g l⁻¹ and 0.88 g l⁻¹ respectively on 56th day. Aggregated cell mass formed on 4th day and it expanded to asteriated colonies on 10th day. Single microcolonies formed on the 21st day had diameters 200-250 μm. Macrocolonies obtained after 28 days had diameters of 5 mm on 42nd day. Discoid colonies were formed as macrocolonies ruptured on 49th day and the diameter reached 15 mm on 56th day. Results of the present study can promote large-scale industrial production of N. commune.