铜绿微囊藻对自养氨氧化细菌的抑制作用

Inhibition effect of Microcystis aeruginosa on autotrophic ammonia-oxidizing bacteria

以铜绿微囊藻FACHB-1027和自养氨氧化细菌(AOB)Nitrosomonas eutropha CZ-4、Nitrosomonas nitrosa WH-1为研究材料,探索铜绿微囊藻对AOB的抑制效应,用透析袋试验确定了抑制物的分子量范围,用GC-MS分析了抑制物质成分.结果表明:铜绿微囊藻对两种AOB氨氧化活性的抑制率分别为90.7%和89.4%,说明铜绿微囊藻能通过非氨氮竞争的方式显著抑制AOB的氨氧化活性;铜绿微囊藻培养物经截留分子量为200Da的透析袋处理后,透过液对AOB氨氧化活性的抑制率为86.9%,透过液中的5,5-2甲基恶唑烷2,4二酮对AOB氨氧化活性的半数抑制浓度为0.4‰~0.8‰,说明铜绿微囊藻能够分泌小分子物质来抑制AOB.

Using Microcystis aeruginosa FACHB-1027 and autotrophic ammonia-oxidizing bacteria(AOB)Nitrosomonas eutropha CZ-4 and Nitrosomonas nitrosa WH-1 as the research material,this study explored the inhibitory effect of M.aeruginosa on AOB.Also,the molecular weight range of the inhibitory substances was determined by dialysis bag tests and the inhibitory substances composition was analyzed by GC-MS.The results showed that the inhibition efficiency of M.aeruginosa on the ammonia oxidation activities of the two AOBs were 90.7%and 89.4%,respectively,indicating that M.aeruginosa can significantly inhibit the ammonia oxidation activity of AOB in a non-ammonium nitrogen competitive manner.After the M.aeruginosa cultures were treated with a dialysis bag with a molecular weight cut-off of 200 Da,the permeate inhibited the ammonia oxidation activity of AOB by 86.9%.The half inhibitory concentration(IC50)of 5,5-2 methyloxazolidine-2,4-dione in the permeate to the ammonia oxidation activity of AOB was 0.4‰~0.8‰,indicating that the M.aeruginosa can secrete small molecular to inhibit the ammonia oxidation activity of the AOB.