Loading Effects of Aminoclays in Co-Culture of Two Cyanobacterial <i>Microcystis</i> and <i>Anabaena</i> Species as an Algicidal Role

Abstract

In recent decades, harmful algal blooms (HABs) have been significantly affecting environments, aquatic ecosystems, and human health, as well as damaging economies, especially near rivers and lakes, and in coastal regions. Microcystis and Anabaena are two genera of harmful cyanobacteria that will often predominate during toxic microalgal blooms. In this study, we employ a method for control and mitigation of HABs by microalgal cell instability using different types of aminoclays (ACs). Allelopathic interactions between the two strains of algae are studied in mono-culture, co-culture, and filtrated cell-free medium in the presence of the ACs. The growth of the Anabaena strain is significantly reduced by the cyanobacterial strains in the co-culture media, and both are significantly affected by the Acs’-enhanced algicidal activity. Anabaena sp. KVSF7 shows higher sensitivity against the ACs than does Microcystis sp. KW. In this way, the algicidal activity of ACs is harnessed, the effects of which are in the order of aluminum aminoclay (AlAC) > magnesium aminoclay (MgAC) > calcium aminoclay (CaAC). The ammonium sites in the ACs carry positive charges to induce instability of HABs along with the electrostatic attraction between algal cells and AC. Therefore, the utilization of the algicidal activity of the ACs can effectively reduce HABs, especially on cyanobacterial blooms.

Keywords

• aminoclays
• cyanobacteria
• co-culture
• harmful algal blooms
• allelopathic effects
• algicidal activity