流体切应力对铜绿微囊藻细胞活性的影响

Effect of fluid shear stress on activity of Microcystis aeruginosa cells.

为讨论流体切应力对铜绿微囊藻细胞活性的影响,本文研究了铜绿微囊藻在0.0,0.3,0.6,0.9Pa切应力作用下的生长情况,并分析了藻细胞生理指标以及藻液指标的变化情况.结果显示,低于0.6Pa的切应力能使藻细胞密度和光合色素含量不断增加,从而促进铜绿微囊藻的生长繁殖.其中0.6Pa对藻细胞生长最有利,此条件既能提高藻细胞光合作用强度和营养盐利用率,又未过度破坏细胞结构.但0.9Pa高切应力将通过对藻细胞结构的破坏来影响膜渗透性,进而抑制铜绿微囊藻生长与代谢.研究表明,流体切应力对铜绿微囊藻细胞的影响体现为“低促高抑”,即适度切应力能够增强铜绿微囊藻细胞的活性,而高切应力会抑制其生长.本文结果将为湖泊水库等水体铜绿微囊藻水华的预防和治理提供了新的思路和方案.

To study the effect of the shear stress on the cell activity of Microcystis aeruginosa,its growth under shear stresses,0.0,0.3,0.6 and 0.9 Pa,was investigated accordingly,and the changes of the algal-cell physiological indicator and the algal-fluid indicator were analyzed.The results indicated that the shear stress below 0.6 Pa can cause the density and photosynthetic pigment content of Microcystis aeruginosa cells increase,promoting their growth and reproduction.The photosynthetic intensity and the nutrient utilization were enhanced by the most favorable shear-stress condition(0.6Pa)for growth,while the cell structure was not excessively damaged.However,the high shear stress,0.9Pa,would affect the membrane permeability of the algal cells by breaking their structure,thereby inhibiting their growth and metabolism.The results demonstrated that the growth of Microcystis aeruginosa cells was affected by the fluid shear stress,manifested as“low promotion and high inhibition”,where their activity was enhanced by moderate shear stress,and their growth was inhibited by the high shear stress.The findings provided a hint or an approach for preventing and managing Microcystis aeruginosa blooms in water bodies,such as lakes and reservoirs.