铜绿微囊藻、四尾栅藻和小环藻竞争实验培养基的选择

改变培养基的氮源形态和碳源浓度,研究铜绿微囊藻、小环藻和四尾栅藻的单藻增长行为,筛选适宜的培养基作为混藻竞争实验的共培养基。研究表明,铜绿微囊藻和四尾栅藻在氨氮培养基中的最大生物量K和最大比增长速率r均不及以硝态氮为氮源的培养基;添加高浓度HCO3-(NaHCO3 1.410 mmol/L)能够提高铜绿微囊藻和四尾栅藻藻细胞对氨氮的吸收能力;较低碳源浓度(NaCO3 0.0943 mmol/L)的培养基中,四尾栅藻的初始比增长速率及生物量远高于铜绿微囊藻,但其最大比增长速率r低于铜绿微囊藻,在实验的第10天左右铜绿微囊藻的生物量超过四尾栅藻;小环藻不能在较高浓度碳源(NaHCO3 1.504 mmol/L)下存活;铜绿微囊藻、四尾栅藻与小环藻均可在以氨氮(HA)或硝态氮(HN)为氮源的培养基中单独培养并达到实验所需生物量,因此,HN和HA可以作为实验室内这三种藻共培养适宜的培养基,为今后研究藻类种间资源竞争机制提供实验依据。

Medium option for Microcystis aeruginosa、 Scenedesmus quadricauda and Cyclotella in competiton experimentations

Growth behaviors in pure culture of Microcystis aeruginosa,Scenedesmus quadricauda and Cyclotella were discussed through changing nitrogen forms and carbon concentrations in this article.Then one sort of fitting medium was selected as a multi-medium.It is reported that the max biomass and max specific growth rate of Microcystis aeruginosa and Scenedesmus quadricauda in ammonium medium were lower than in nitrate medium;It is proved that ammonium absorption ability of Microcystis aeruginosa and Scenedesmus quadricauda was improved by adding high HCO3-(NaHCO3 1.410 mmol/l)concentration.Original specific growth rate and Original biomass of Scenedesmus quadricauda were largely higher than Microcystis aeruginosa in low carbon(NaCO30.0943 mmol/l)concentration medium.But its max specific growth rate was lower than Microcystis aeruginosa.The bio-mass of Microcystis aeruginosa surpassed Scenedesmus quadricauda after the test had begun 10 days;Cyclotella could not survive in low carbon(NaHCO3 1.504 mmol/l) concentration mediaum;As a result,Microcystis aeruginosa,Scenedesmus quadricauda and Cyclotella can be pure cultured in ammonium(HA) or nitrate(HN) as nitrogen resource medium and their biomass have reached the quantity which experimentation needed.Therefore HN and HA are feasible multi-culture-media for this three algae in lab.