水体pH和铜绿微囊藻增殖的关系研究

Study on the Relationship between pH and Cell Proliferation of Microcystis aeruginosa

以水华生物铜绿微囊藻(Microcystis aeruginosa)为研究对象,在实验室内研究了水体pH变化和微藻生长的关系,以期了解铜绿微囊藻对水体pH的适应和调节能力。试验分2组,一组每天测定水体实际pH后调整水体pH为设计值,另一组试验开始时调节pH至设计值后不人为改变,每天测定pH。结果表明,铜绿微囊藻偏好碱性环境,并对环境的pH有一定的适应和调节能力。在每天调节pH为11的处理组,试验1周内铜绿微囊藻生长较快,并有较高的细胞生物量;铜绿微囊藻对每天调节pH为5～11和初始pH为5～11的水体都有很高的调节能力,使pH趋向于适宜范围,试验中实测pH7.3～9.4;对强酸和强碱环境的调控能力较弱,但对强碱环境的调节能力大于对强酸环境的,持续1周的强酸或强碱环境并未使铜绿微囊藻很快灭失,仍有发生水华的可能。

Microcystis aeruginosa is one of the preponderant Cyanobacteria species causing harmful blooms in the lakes and the reservoirs.The study,which included two experiments,focused on the relationship between pH and the cell proliferation of M.aeruginosa in order to analyze the accommodation ability of this species against the pH stress.In the first experiment,the pH values were controlled every day to the designed value after monitoring,while in the second the values were monitored without controlling.The results showed that this species preferred alkali condition,and had the capacity to adapt itself to and to adjust the pH of the water to some extent.In the pH-controlled experiment,M.aeruginosa grew faster and had higher density within a week when the pH value was 11.This cyanobacterium species had higher adjusting ability when the pH values in both controlled and uncontrolled pH experiments were between 5 and 11,and changed the pH values to its optimal values which were monitored actually as 7.3-9.4.The adjusting ability was better in a strong alkali environment than in a strong acid environment,although this species had weak controlling ability in very strong alkali or acid conditions.In this study,the species did not die off in strong alkali or strong acid conditions during the experimental period.Therefore the possibility of water bloom would still exist.