南京农业大学学报2017，Vol.40Issue(4)：625-631,7.DOI:10.7685/jnau.201610003
短短芽孢杆菌发酵液对铜绿微囊藻的抑制效应
The inhibitory effect of the fermentation filtrate of Brevibacillus brevis on Microcystis aeruginosa
摘要
Abstract
[Objectives]The frequent outbreaks of algal-bloom have done great harm to ecosystems and human life.The aim of this study was to explore a high-effective and eco-friendly algicide from microbes.[Methods]The inhibitory rates of the sterile filtrate at different fermentation time and different concentrations were determined by flow cytometry.The morphology of the cyanobacterial cells was observed by laser scanning confocal microscope and electron microscope.The changes of photosynthetic activities between control and treated cells were measured by using a pulse amplitude-modulated fluorescence monitoring system.In addition,the changes of the algicidal activities of the sterile filtrate under different temperature,pH value and protease treatment were detected.[Results]The sterile filtrate with the added amount of 0.3％,0.7％,1.0％ and 2.0％ had an inhibitory rate of 51.89％,79.89％,89.47％ and 86.94％,respectively.There was no significant difference between the inhibitory activity of 48 and 72 h fermentation filtrate,both of which were better than that of 24 h fermentation.After 6 days' treatment,Fv/Fm and ETRmax value decreased significantly,which suggested the inhibition of photosynthesis.Under the laser scanning confocal microscope,many cells were found to remain at the end of cell division,forming 2-or 4-cell aggregates.The proportion of 2-and 4-cell after treatment for 6 d by 1.0％ of fermentation filtrate was 62.23％ and 14.95％,respectively,showing the cell division was severely blocked.Transmission electron microscope showed that the algal cells were seriously damaged,with the phenomenon of plasmolysis,the rupture of the thylakoid and cytomembrane.The molecular weight of the main active substances was speculated to be less than 10× 103 by ultrafiltration of the sterile filtrate.After treatment for 6 h at 4,25 and 37 ℃C,the inhibitory activity had no marked difference from the control,which showed that the active substances were stable at these temperatures.In addition,after treatment at pH value 2-12,the active substances remained good inhibitory activity.The fermentation filtrate was not sensitive to trypsin or protease K.[Conclusions]B15 can inhibit the growth and reproduction of M.aeruginosa by secreting small molecules,which reduce its photosynthetic efficiency and repress cell division,with a high and lasting inhibitory rate.关键词
短短芽孢杆菌/铜绿微囊藻/抑藻剂/抑藻效应Key words
Brevibacillus brevis/Microcystis aeruginosa/algicide/cyanobacterial inhibition effect分类
生物科学引用本文复制引用
张小倩,张炜,卢亚萍,高胜玲,汪瑾..短短芽孢杆菌发酵液对铜绿微囊藻的抑制效应[J].南京农业大学学报,2017,40(4):625-631,7.基金项目
国家自然科学基金项目(31300644) （31300644）
南京农业大学中央高校基本业务费专项资金(KJQN201424) （KJQN201424）
