氮磷对水华束丝藻生长及生理特性的影响

EFFECTS OF NITRATE AND PHOSPHORUS ON GROWTH AND PHYSIOLOGICAL CHARACTERISTICS OF APHANIZOMENON FLOS2AQUAE FROM DIANCHI

  • 摘要: 从滇池分离得到水华束丝藻藻株, 以BG11为基础培养基, 在(25±1)℃, 光照强度20μE/m2.s, 光/暗周期为16h:8h的培养条件下, 水华束丝藻的生长周期约为28d, 以光密度(OD665)为指标的生长曲线符合典型的"S"型;在实验浓度范围内, N、P的浓度变化均对水华束丝藻的生长产生影响, 在一定范围内(NO3--N:1.6-245.1 mg/L;PO43--P:0.3-1.4 mg/L), 高浓度的N、P有利于水华束丝藻的生长, 但浓度过高(NO3--N>245.1 mg/L;PO43--P>6.9 mg/L)时, 则对其生长产生抑制作用;N、P在缺乏和浓度很低时可对水华束丝藻光系统Ⅱ活性(Fv/Fm)产生显著影响(pp<0.05). 这一结果表明, 在低N、P营养环境中, 水华束丝藻可通过调节自身的酶系统来提高对营养的吸收和利用, 从而满足自身生长和细胞增殖的需要.

     

    Abstract: Aphanizomenon flos-aquae (A1 flos-aquae) isolated from eutrophic Lake Dianchi was cultured in BG11 medium, and it was maintained at (25 ±1) ℃ (with an illumination of 20μE/m2.s, under a light/dark cycle of 16 :8) . The growth cycle of A1 flos-aquae was approximately 28d and the growth curve was fit well with the typical“S”model . Concentrations of NO3--Nand PO43--P may affect the growth of A1 flos-aquae with better growth under higher concentration of N and P , but excessive N and P may restrain the growth of A1 flos2aquae. Fv/Fmof A1 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 < 0105) . Activities of nitrate reductase and acid/alkaline phosphatase were not linear with the changes of N and P concentration. These results indicated that A1 flos-aquae could adapt to variant circumstances with different nutritional levels due to their physiological and biochemical strategies1.

     

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