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

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: ligh 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 witamins tested. Likewise, hormones such as kinetin and giberellin exhibited stumulatory 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 phos phocreatine were comparatively similar; half-saturation constant, maximum growth rate, minimum cell quota and level for saturated growth yield were about 0.01-0.02 mg P/ℓ, 0.8/day, 0.1-0.2 pg P/cell, and 0.4-0.7 mg P/ℓ, respectively

Growth responses of Spirulina platensis to some physico-chemical factors and the kinetics of phosphorus utilization

The growth responses of Spirulina platensis NIES-46, a brackishwater strain originally isolated from Lake Texcoco Mexico, to some physico-chemical factors and nutrients were investigated. The optimum conditions for growth were the following: light intensity of 160 µE m-2 sec-1, temperature of 30°C, pH 10, and chlorinity of 0.55‰. NIES-46 strain could utilize both inorganic and organic phosphorus sources. Values on the different growth parameters for orthophosphate and other organic phosphorus sources were as followings: half-saturation constant of 0.02-0.07 mg-P/l; maximum growth rate of 0.8-1.0/d; minimum cell quota of 0.08-0.32 pg-P/cell, and level for saturated growth yield of 0.3-1.0 mg-P/l. The result that this species utilized effectively a rather wide range of both inorganic and organic phosphorus and showed a high growth rate suggests that mass production of this species is possible by recycling organic waste