Synthetic Biomimetic Polymethacrylates: Promising Platform for the Design of Anti-Cyanobacterial and Anti-Algal Agents

Abstract

Extensive, uncontrolled growth of algae and cyanobacteria is an environmental, public health, economic, and technical issue in managing natural and engineered water systems. Synthetic biomimetic polymers have been almost exclusively considered antimicrobial alternatives to conventional antibiotics to treat human bacterial infections. Very little is known about their applicability in an aquatic environment. Here, we introduce synthetic biomimetic polymethacrylates (SBPs) as a cost-effective and chemically facile, flexible platform for designing a new type of agent suitable for controlling and mitigating photosynthetic microorganisms. Since SBPs are cationic and membranolytic in heterotrophic bacteria, we hypothesized they could also interact with negatively charged cyanobacterial or algal cell walls and membranes. We demonstrated that SBPs inhibited the growth of aquatic photosynthetic organisms of concern, i.e., cyanobacteria (Microcystis aeruginosa and Synechococcus elongatus) and green algae (Chlamydomonas reinhardtii and Desmodesmus quadricauda), with 50% effective growth-inhibiting concentrations ranging between 95 nM and 6.5 μM. Additionally, SBPs exhibited algicidal effects on C. reinhardtii and cyanocidal effects on picocyanobacterium S. elongatus and microcystin-producing cyanobacterium M. aeruginosa. SBP copolymers, particularly those with moderate hydrophobic content, induced more potent cyanostatic and cyanocidal effects than homopolymers. Thus, biomimetic polymers are a promising platform for the design of anti-cyanobacterial and anti-algal agents for water treatment.

Preparation and Application of Fe-Al-SiO2 Poly-Coagulants for Removing Microcystis aeruginosa from Water

“…The temperature was kept constant at 21 • C, and the process was shaded from the light. The Chl-α concentration was calculated using Equation (6). c = 11.084 (λ 663 − λ 750 ) − 3.914 (λ 645 − λ 750 ) (6) where c represents the Chl-α concentration (in mg/L).…”

“…Microcystis aeruginosa is one of the most pervasive bloom-forming species within the phylum Cyanobacteria, distributed in freshwater [4]. The distribution density of CyanoHABs threatens the biodiversity and function of the water ecosystem and deteriorates water quality for subsequent uses [5,6]. Additionally, Microcystins (MCs) produced by Microcystis aeruginosa are hepatotoxic, nephrotoxic, reproductive toxic, and neurotoxic, endangering human health through exposure routes such as drinking, skin contact, and inhalation [4,5].…”

Biomimetic antimicrobial polymers—Design, characterization, antimicrobial, and novel applications

“…Most polymers interacting with algal or cyanobacterial cells in solution (Table 1, illustration in Figure 2) inhibited growth (algostatic and/or cyanostatic effect), and some of them caused cell death (algicidal and/or cyanocidal effect). The proposed molecular mechanisms of algicidal or cyanocidal activity of biomimetic polymethacrylates, branched PEIs, PPI-DEN, or cationic PAMAM dendrimers cover (1) binding to the cell surface, (2) crossing the cell wall, and (3a) destabilizing and permeabilizing plasma membrane, leading to membrane disruption and cell lysis, or (3b) polymer internalization and disrupting structure and function of chloroplasts or thylakoids, leading to chlorophyll and photosynthesis deteriorations (Gonzalo et al, 2015;Mikula et al, 2021;Petit et al, 2012Petit et al, , 2010. PAMAM dendrimers and core-shell polystyrene-copper oxide nanoparticles also elevated ROS (reactive oxygen species) production in algal and/or cyanobacterial cells (Gonzalo et al, 2015;Petit et al, 2010Petit et al, , 2012Saison et al, 2010).…”

Biodegradability of Gel-Forming Superabsorbents for Soil Conditioning: Kinetic Assessment Based on CO2 Emissions

“…Along with the optimization of the water retention and soil structure, gel-forming polymers can be successfully used as agents for controlled release systems for pesticides and agrochemicals [4][5][6]. Intercalation of natural and synthetic biocides (heavy metal ions and nanoparticles, ammonium or sulfonium salts, synthetic fungicides, and antimicrobial peptides) in composite acrylic superabsorbents, as well as biomimetic technologies for the synthesis of polymethacrylates with a cationic and membranolytic biocidal effect, allow obtaining materials for environmentally friendly control of pathogens with low effective concentrations E 50 of biocides near 10-100 ppm (soil) and 100-6000 ppb (water) [11][12][13].…”