Abstract
Phaeocystis globosa is regarded as a notoriously harmful algal bloom species. Suppressing harmful algae using algicidal substances extracted from plants is considered an effective method. The physiological and biochemical processes of P. globosa were explored by exposure to different concentrations of aqueous extracts of Cyperus rotundus. All treatments indicated various inhibitory effects on the algal growth compared to the control samples without adding extracts. At 48 h, the 4, 8, and 16 mg/mL treatment groups showed a significant inhibitory effect, consistent with a decrease in the chlorophyll-a content and photosynthetic efficiency. The images of the transmission electron microscope (TEM) further confirmed that a subset of the cells in the treatment groups exhibited morphological anomalies. The algicidal active substances were mainly identified as phenolic acids containing maximal content of quinic acid in aqueous extracts according to the results of ultra-high-performance liquid chromatography-tandem time-of-flight mass spectrometer (UPLC-HRMS). The 50% anti-algal effect concentration of quinic acid was 22 mg/L at 96 h (EC50–96h). Thus, the phenolic acids might be considered as major inhibitors of the growth of P. globosa. These results demonstrated that the aqueous extracts of C. rotundus could potentially control the growth of P. globosa.
Highlights
Algal blooms are natural phenomena in the aquatic ecosystem and are designated as harmful algal blooms (HABs) with detrimental effects on ecosystems
This study explored the algicidal mechanism of C. rotundus aqueous extracts and discussed the bioavailability of phenolic compounds, facilitating the extraction and utilization of secondary metabolites from marine plants
The variables comprising photosynthetic efficiency and cell integrity were observed based on the parameters of the OJIP curve, JIP-test parameters and the images of the cell ultrastructure, respectively
Summary
Algal blooms are natural phenomena in the aquatic ecosystem and are designated as harmful algal blooms (HABs) with detrimental effects on ecosystems. Some HABs species gain superiority in resource competition for mass proliferation, while leading to hypoxia or the mortality of marine organisms due to high biomass and oxygen depletion due to their self-decomposition [2]. Toxic HABs species may produce toxicants that are absorbed by aquatic organisms, especially shellfish, threatening human life [3]. Phaeocystis globosa (Prymnesiophyceae) is a dense bloom-forming, broad temperature tolerance, and broad salinity tolerance HABs species [4]. It leads to massive mortality of fishes, and numerous
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
