Effect Of Ecological Factors On Growth Of The Freshwater Filamentous Cyanobacteria Osillatoriales

Abstract: The effect of main factors on the growth of the freshwater filamentous cyanoalgae was studied under laboratory condition: Oscillatoia cortiana, Oscillatoria acuminate, Oscillatoria anguina, Leptolyngbya foveolara. Strains were cultivated in BG11 medium under continuous illumination. Growth was determined by measuring concentration of chlorophyll a and growth rate. Orthogonal test was used to study the effect of five environmental factors--light intensity, temperature, concentration of nitrate-nitrogen, phosphorus, Fe on the growth of filamentous cyanoalgae in alkaline environment and their suitable growth requirements as following: O. cortiana: 1000 lux, 25℃, 105 nmol/L, 6 mg/mL, 0.02 mg/mL, O. acuminate:1000 lux, 25℃, 105 nmol/L, 6 mg/mL, 0.06 mg/mL, O. anguina: 3000 lux, 35℃, 104 nmol/L, 1mg/mL, 0.06 mg/mL, L. foveolara: 5000 lux, 35℃, 105 nmol/L, 2mg/mL, 0.06 mg/mL.Five environmental factors as a whole make effect on filamentous cyanoalgae in Orthogonal test, regardless of which factor's change, can be coordinated with other factors, otherwise the chlorophyll a content reduces.