磷对常见淡水微囊藻释放β-环柠檬醛(β-cyclocitral)的影响

The effects of phosphorus onβ-cyclocitral release from the common freshwater Microcystis

藻类释放的异味化合物导致水体嗅味问题已成为世界性的水环境问题之一,引起了社会的广泛关注.通过室内实验,研究了磷(P)对8种常见微囊藻(Microcystis)释放异味物质—β-环柠檬醛(β-cyclocitral)的影响.结果表明,P对微囊藻生长及释放β-cyclocitral有较大影响,其中,中低P浓度(0~0.5 mg·L^(-1))有利于多数种类的微囊藻生长,但对藻类活性(F_(v)/F_(m))的影响与叶绿素a(Chl-a)并不一致.铜绿微囊藻(Microcystis aeruginosa)释放β-cyclocitral的能力与P浓度成正比,也是常见微囊藻中β-cyclocitral产率(β-cyclocitral/Chl-a)最高的藻类,可达34.2 ng·μg^(-1),其次为华美微囊藻(Microcystis elabens)达24.1 ng·μg^(-1),惠氏微囊藻(Microcystis wesenbergii)的β-cyclocitral产率最低,仅为0.21 ng·μg^(-1).数据分析表明不同种微囊藻,在不同P浓度下释放β-cyclocitral的巨大差异与其产率紧密相关,β-cyclocitral产率与藻类活性(F_(v)/F_(m))紧密相关.结合文献报道的野外调查数据分析,同样表明在富营养化湖泊中随着P浓度的升高,铜绿微囊藻(Microcystis aeruginosa)释放β-cyclocitral增加,与室内实验结果一致.本研究通过室内实验,揭示了P对不同微囊藻生长和活性影响的差异,是造成不同微囊藻释放β-cyclocitral差异的重要原因,得出P是调节微囊藻释放β-cyclocitral的重要因素,这对富营养化水体中异味物质的防治有重要意义.

The off-flavor issue of water attributable to the odorous compounds released by algae has become one of the world’s water environmental problems,and has aroused widespread extensive public concern.Using the laboratory experiments,this study investigated the effects of phosphorus(P)on the release of odorous substances-β-cyclocitral(β-cyclocitral)from eight common Microcystis species.Results showed that P was able to significantly influence the growth and release of β-cyclocitral of Microcystis.In particular,medium and low P concentrations(0~0.5 mg·L^(-1))were beneficial to the growth of most species of Microcystis,while the effects on algal activity(F_(v)/F_(m))were not consistent with that of chlorophyll a.The ability of Microcystis aeruginosa to release β-cyclocitral was proportional to the P concentration.The Microcystis aeruginosa was found with the highest β-cyclocitral yield rate(β-cyclocitral/Chl-a,up to 34.2 ng·μg^(-1)),followed by Microcystis elabens(24.1 ng·μg^(-1)),and Microcystis wesenbergii was observed with the lowest β-cyclocitral yield rate of only 0.21 ng·μg^(-1).Data analysis indicated that the large disparities in the release of β-cyclocitral under various P concentrations among different species of Microcystis were strongly related to their β-cyclocitral yield rates,and the latter were also associated with the algal activity.The field data also demonstrated that with the increase of P concentration in eutrophic lakes,more β-cyclocitral was released by Microcystis aeruginosa,which was in line with the results of our laboratory experiments.Through laboratory experiments,this study revealed that the varied effects of P on the growth and activity of different Microcystis,which was the main contributor for the release of β-cyclocitral by different Microcystis.Our study illustrated that P is an important factor regulating the release of β-cyclocitral by Microcystis,which is of great significance for the prevention and control of odorous substances in eutrophic water.