摘要
[目的]微囊藻水华给湖泊生态系统及人类健康带来很大危害,本研究旨在探寻高效环保的微生物抑藻材料。[方法]通过流式细胞仪测定短短芽孢杆菌B15不同发酵时间及添加量下无菌发酵上清液的抑藻率,通过激光共聚焦显微镜和电子显微镜观察处理后的藻细胞形态,并通过叶绿素荧光仪测定处理前、后藻细胞光合作用的变化。另外,检测了发酵上清液在不同温度、p H值和蛋白酶处理下的活性变化。[结果]0.3%、0.7%、1.0%和2.0%添加量的发酵液处理6 d后抑藻率分别为51.89%、79.89%、89.47%和86.94%。发酵液发酵48和72 h抑藻活性无明显差异,但略优于发酵24 h。发酵上清液处理6 d后,藻细胞Fv/Fm、ETRmax值均显著下降,表明其光合作用受到抑制。激光共聚焦显微镜观察发现:许多细胞停留在分裂末期,呈2细胞或4细胞状态。1.0%发酵上清液处理6 d后藻液中2细胞和4细胞所占比例分别达到62.23%和14.95%,表明藻细胞分裂增殖严重受阻。透射电镜观察结果显示:经处理后藻细胞严重受损,出现质壁分离、类囊体结构及细胞膜断裂的现象。发酵上清液超滤结果显示抑藻活性物质相对分子质量小于10×103。将抑藻物质在4、25和37℃处理6 h后,抑藻活性和对照相比无显著差异,说明该活性物质在低温下有较好的稳定性。另外,在p H值2~12的范围内,抑藻物质都保持很好的活性。抑藻物质对胰蛋白酶和蛋白酶K均不敏感。[结论]短短芽孢杆菌B15通过分泌小分子化合物高效而持久地抑制铜绿微囊藻的生长繁殖,降低其光合作用效率,并阻遏细胞的分裂。
[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,p H 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/Fmand ETRmaxvalue 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 ℃,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 p H value 2-1
出处
《南京农业大学学报》
CAS
CSCD
北大核心
2017年第4期625-631,共7页
Journal of Nanjing Agricultural University
基金
国家自然科学基金项目(31300644)
南京农业大学中央高校基本业务费专项资金(KJQN201424)
关键词
短短芽孢杆菌
铜绿微囊藻
抑藻剂
抑藻效应
Brevibacillus brevis
Microcystis aeruginosa
algicide
cyanobacterial inhibition effect
