Effects of Toxic and Non-Toxic Microcystis aeruginosa on the Defense System of Ceratophyllum demersum- Scenedesmus obliquus

Microorganisms. 2024 Nov 8;12(11):2261. doi: 10.3390/microorganisms12112261.

Abstract

The effects of toxic and non-toxic Microcystis aeruginosa on the Ceratophyllum demersum-Scenedesmus obliquus system were simulated in the laboratory, and some parameters in relation to these organisms were measured. In this experiment, C. demersum increased the biomass of S. obliquus, and both toxic and non-toxic M. aeruginosa significantly inhibited the colony formation of S. obliquus and inhibited the promotion of S. obliquus biomass. On the 14th day, the soluble polysaccharide content of C. demersum decreased when it was coexisted with S. obliquus, but it rose again because of M. aeruginosa, which significantly increased the protein content of C. demersum. The species composition and diversity of epiphytic microorganisms also vary with different treatments. Proteobacteria is dominant in all the groups, especially in the Toxic_SMC group. In addition, bacteria that can degrade organic pollutants are more abundant in Toxic_SMC group. This study focuses on the defense response of S. obliquus induced by C. demersum under the pressure of toxic or non-toxic M. aeruginosa and evaluates the changes to C. demersum and its epiphytic microorganisms, which provides insights for the study of aquatic plant-algae integrated action systems in eutrophic or cyanobacterial blooms.

Keywords: Ceratophyllum demersum; MC-LR; Scenedesmus obliquus; algal colony; induced defense; microorganism.

Grants and funding

This work was financially supported by the Key Scientific and Technological Project of Henan Province (No. 232102321056), the Young Backbone Teachers Project of Henan Province (No. 2020GGJS064), the Key Scientific and Technological Project of Henan Province (No. 232102320256), the Project of Huanghe River Fisheries Resources and Environment Investigation from the MARA, P.R. China, and the Henan Provincial Natural Science Foundation (No. 242300420496 and 242300421578).