粘着剑菌溶藻效能与溶藻过程藻胞内物质释放

The Algicidal Efficiency and Release of Algal Intracellular Substance During the Algae-lysing Process by Ensifer adhaerens

粘着剑菌菌株r23(Ensifer adhaerens)是从微囊藻水体中筛选出的溶藻菌。文章研究了不同温度和投加方式下r23溶解铜绿微囊藻(Microcystis aeruginosa)的效果,以及不同投加方式下胞内外藻毒素-LR(MC-LR)的变化和胞内有机物质的释放。结果显示,r23菌液的EC_(50,72 h)是2.04×10~6CFU/m L,能够在温度低至15℃时仍有95%的溶藻效果。在没有培养基条件下,菌体细胞不具有溶藻能力,菌液上清液能够实现70%的溶藻效果。菌液5%(V/V)的投加剂量会刺激藻细胞产生更多MC-LR,总MC-LR达到256.7 mg/L,高于对照样的232.1 mg/L,而10%和20%的投加剂量会抑制MC-LR产生,总MC-LR浓度在溶藻30 d后会降至36.8 mg/L和12.24 mg/L。三维荧光测定结果显示,菌液的投入以及藻细胞的死亡会导致水溶液中类蛋白质物质(λ_(Ex)/λ_(Em)=280 nm/350 nm;λ_(Ex)/λ_(Em)=230 nm/330 nm)含量增加,而类腐殖质物质(λ_(Ex)/λ_(Em)=340 nm/430 nm)变化不大。

Ensifer adhaerens（r23）is an algicidal bacterium screened from the Microcystis bloom water.This paper studied the algicidal effects of temperature and different dosing modes of strain r23 on Microcystis aeruginosa,as well as the variation of intracellular/extracellular microcystin-LR and intracellular organic matters.The results showed that the EC50,72 hof strain r23 was 2.04×10^6CFU/m L.The strain r23 could preformed the algicidal activity even if the temperature was as low as 15℃,achieving 95%of algae-lysing efficiency.The strain r23 could not inhibit the growth of M.aeruginosa without the presence of media.The supernatant of bacterial culture reached 70%of algae-lysing efficiency.The dosage of 5%（V/V）bacterial culture stimulated algal cells to produce more MC-LR with the total（intra-and extra-cellular）MC-LR of 256.7μg/L after 30 days,slightly higher than 232.1μg/L of control samples.However,the higher dosage of 10%and 20%compressed the MC-LR production and the total MC-LR were apparently decreased to 36.8μg/L and 12.2μg/L after 30 days,respectively.The three-dimensional fluorescence matrix showed that the addition of strain r23 culture and the lysing of algae cells resulted in the increase of protein-like substances（λEx/λEm=280 nm/350 nm;λEx/λEm=230 nm/330 nm）,but humus substances（λEx/λEm=340 nm/430 nm）with unchanged.