缺磷及高光照条件下紊动对铜绿微囊藻生长的影响

通过试制隔栅搅拌模拟紊动装置，设置格栅转动频率为0，500，1000，1500Hz（对应紊流能量耗散率范围0～8.93×10^-3m²/s³），研究高光照与缺P的不利环境条件下紊动对铜绿微囊藻生长的影响.结果发现，在高光照（8000lx）下，微囊藻生长明显受到抑制，静止条件下藻浓度仅为正常光照的47.7%，但紊动可一定程度上减缓高光环境的影响，其中高光照下1000Hz组藻浓度最高，相对静止提高了1.8倍.高光照试验组的叶绿素a含量是正常光照条件1.52~1.78倍，因此高光照并未促进藻细胞的生长分裂，而叶绿素a的大量累积可能是铜绿微囊藻应对高光照不利条件作出的抵御反应.在缺P条件下，藻生物量仅为正常营养条件1/6~1/4，但随紊动强度增加，藻生物量略有增加，而叶绿素较初始浓度增加明显，其中1000Hz组生长情况最好.水体紊动可缓解高光照、缺P等恶劣环境条件对铜绿微囊藻生长的抑制，叶绿素a的累积可能是藻细胞对不利环境条件的响应.

Effect of flow turbulence on the growth of Microcystis aeruginosa under phosphorus deficiency and high light intensity conditions

A grid-stirring turbulence generation device was applied with the grid rotation frequency of 0, 500, 1000and 1500Hz, corresponding to the turbulent energy dissipation rate ranged in 0~8.93×10^-3m²/s³, to investigate the effect of flow turbulence on the growth of Microcystis aeruginosa under high light intensity and phosphorus deficiency conditions. Under high light intensity (8000lx), the growth of Microcystis was significantly inhibited, and the algal concentration under the static condition was only 47.7% of that under normal light intensity. However, turbulence could alleviate the effect of high light environment to a certain extent. Among them, the algae concentration in the 1000Hz group was the highest, which was 1.8times higher compared to the static group. The Chl-a content in the high light intensity group was 1.52 to 1.78 times that of normal light conditions, which indicated that high light intensity might not promote the growth and division of algal cells, and the accumulation of Chl-a might be the defense response of Microcystis aeruginosa to the adverse conditions of high light intensity. In the absence of phosphorus, the algal biomass was only 1/6~1/4 of that in normal nutritional conditions. However, with the increase of turbulence intensity, the algae biomass increased slightly and the Chl-a concentration increased significantly from the initial concentration. Among them, the 1000Hz group was found to be with the best growth. Flow turbulence can alleviate the harsh environments such as high light intensity and phosphorus deficiency for algae growth and accumulation of Chl-a might be the defense response of algal cells to the adverse environment.