Effects of physico-chemical factors and nutrients on the growth of Spirulina platensis isolated from Lake Kojima, Japan.

Abstract

The effects of physico-chemical factors and nutrients on the growth responses of Spirulina platensis isolated from Lake Kojima (K-2 strain) were determined. The optimum conditions for growth were the following: light intensity of 2, 500-10, 000 lx, pH 6.5-9.0, 30 to 35°C temperature and 0-7.6% of chlorinity. S. platensis (K-2 strain) requires no vitamins for growth essentially. However, growth enhancement was observed with vitamin B12 among the B-group vitamins tested. Likewise, hormones such as kinetin and giberellin exhibited stimulatory effect on growth. The alga could utilize inorganic and organic phosphorus sources. Values on the different growth parameters for orthophosphate, β-glycerophosphate, adenosine diphosphate, and phosphocreatine were comparatively similar; half-saturation constant, maximum growth rate, minimum cell quota and level for saturated growth yield were about 0.01-0.02mg P/l, 0.8/day, 0.1-0.2pg P/cell, and 0.4-0.7mg P/l, respectively.