Aphanizomenon flos-aquae (A. flos-aquae) isolated from eutrophic Lake Dianchi was cultured in BG11 medium, and it was maintained al. (25 +/- 1)degrees C (with an illumination of 20 mu E/m(2) center dot s, under it light/dark cycle of 16:8). The growth cycle of A. flos-aquae was approximately 28d and the growth curve was fit well with the typical "S" model. Concentrations of NO3--N and PO43--P may affect the growth of A. flos-aquae with better growth under higher concentration of N and P, but excessive N and P may restrain the growth of A. flos-aquae. Fv/Fm of A. flos-aquae can only affected by the absence or unusually low contents of N and P. Nitrate reductase, acid phosphatase under low concentrations, of N and P were significantly higher than that of the control (cultured in BG11 medium, p < 0.05). Activities of nitrate reductase and acid/alkaline phosphatase were not linear with the changes of N and P concentration. These results indicated that A. flos-aquae could adapt to variant circumstances with different nutritional levels due to their physiological and biochemical strategies.
Liu Yong-Mei; Liu Yong-Ding; Li Dun-Hai; Shen Yin-Wu.Effects of nitrate and phosphorus on growth and physiological characteristics of Aphanizomenon flos-aquae from Dianchi,Acta Hydrobiologica Sinica,2007,31(6):774-779