Tan Xiao, Shu Xiaoqian, Guo Jiujia, Parajuli Keshab, Zhang Xidong, Duan Zhipeng
Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing, 210098, China.
Origin Energy Limited, Adelaide, SA, 5000, Australia.
Bull Environ Contam Toxicol. 2018 Jul;101(1):117-123. doi: 10.1007/s00128-018-2348-y. Epub 2018 May 9.
Ultrasound can be used to induce cell resonance and cavitation to inhibit cyanobacterial growth, but it can also lead to increase in dissolved nutrients because of cell disruption. This study investigated the process from cell inactivation to disruption of Microcystis aeruginosa. Algal cells were sonicated (at 35 kHz) under various intensities and durations. Results showed that chlorophyll a content and F/F values decreased slightly within the first 5 min. Superoxide dismutase activity was stimulated and its peak value appeared at the fifth minute. After 20 min, considerable number of ruptured cells were observed and the concentrations of dissolved nitrogen and phosphorus increased rapidly. Finally, ammonia and nitrate merely composed a small portion of dissolved nitrogen. This study demonstrated that excessive ultrasound treatment can significantly rupture algal cells and lead to the release of cellular inclusions, which may cause ecological issues or public health problems. Based on our findings, ultrasonic intensity controlled at 0.035 W/mL and applied for a duration of 20 min delivers the optimal result in effectively inhibiting physiological activities of Microcystis aeruginosa without marked cell disruption. This will ultimately help to achieve algal control, while conserving energy and preserving the environment and human health.
超声波可用于诱导细胞共振和空化以抑制蓝藻生长，但由于细胞破裂，它也会导致溶解养分增加。本研究调查了铜绿微囊藻从细胞失活到破裂的过程。在不同强度和持续时间下对藻类细胞进行超声处理（35kHz）。结果表明，叶绿素a含量和F/F值在前5分钟内略有下降。超氧化物歧化酶活性受到刺激，其峰值出现在第5分钟。20分钟后，观察到大量破裂细胞，溶解态氮和磷的浓度迅速增加。最后，氨和硝酸盐仅占溶解态氮的一小部分。本研究表明，过度的超声处理会显著使藻类细胞破裂并导致细胞内含物释放，这可能会引发生态问题或公共卫生问题。基于我们的研究结果，将超声强度控制在0.035W/mL并施加20分钟，能在有效抑制铜绿微囊藻生理活动的同时，不会造成明显的细胞破裂，从而达到最佳效果。这最终将有助于实现藻类控制，同时节约能源、保护环境和人类健康。
