Jiangsu Province Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing 210023, China.
Jiangsu Province Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing 210023, China.
J Hazard Mater. 2021 Oct 15;420:126616. doi: 10.1016/j.jhazmat.2021.126616. Epub 2021 Jul 9.
Removal of harmful cyanobacteria is an extremely urgent task in global lake management and protection. Conventional measures are insufficient for simultaneously removing cyanobacteria and hazardous cyanotoxin, efficient and environmental-friendly measures are therefore particularly needed. Herbivorous protozoa have great potentials in controlling algae, however, large-sized colonial Microcystis is inedible for protozoa, which is a central problem to be solved. Therefore, in present study, a measure of protozoa grazing assisted by ultrasound was investigated in laboratory scale for eliminating harmful colonial Microcystis. The results showed that with ultrasound power and time increasing, the proportion of unicellular Microcystis increased significantly. With Ochromonas addition, approximately 80% of colonial Microcystis and microcystin was removed on day 4 under ultrasound power of 100 W for 15 min, while Ochromonas only reduced Microcystis by less than 20% without assistance of ultrasound. Moreover, when directly exposed to low-intensity ultrasound, Ochromonas showed strong resistance to ultrasound and were not inhibited in grazing Microcystis. Overall, ultrasound increases edible food for protozoa via collapsing Microcystis colonies and assists Ochromonas to remove Microcystis, thus intermittently collapsing colonial Microcystis using low-intensity ultrasound can significantly improve the removal efficiency of Microcystis by protozoa grazing, which provided a new insight in controlling harmful colonial Microcystis.
去除有害蓝藻是全球湖泊管理和保护中极其紧迫的任务。常规措施不足以同时去除蓝藻和有害蓝藻毒素，因此特别需要高效且环保的措施。食藻原生动物在控制藻类方面具有巨大的潜力，然而，大型集胞藻微囊藻对于原生动物来说是不可食用的，这是需要解决的核心问题。因此，本研究在实验室规模上调查了原生动物在超声辅助下的摄食措施，以消除有害的集胞藻微囊藻。结果表明，随着超声功率和时间的增加，单细胞微囊藻的比例显著增加。当添加眼虫时，在 100 W 超声功率下处理 15 分钟，第 4 天可去除约 80%的集胞藻微囊藻和微囊藻毒素，而没有超声辅助时眼虫仅能将微囊藻减少不到 20%。此外，当直接暴露于低强度超声时，眼虫对超声表现出很强的抵抗力，在摄食微囊藻时不受抑制。总体而言，超声通过破坏微囊藻集聚会增加原生动物可食用的食物，并协助眼虫去除微囊藻，因此间歇地用低强度超声破坏集胞藻微囊藻可以显著提高原生动物摄食去除微囊藻的效率，为控制有害集胞藻微囊藻提供了新的思路。
