MAISRC researchers are evaluating eco-friendly biological coatings to reduce biofouling, curb the spread of invasive species, and improve zebra mussel management.
Biofouling is a natural phenomenon that affects submerged structures, boats, docks, and anchors, adding significant costs to Minnesota’s industries and serving as a vector for the spread of numerous invasive species in Minnesota waters. A current method of combating biofouling involves the use of metals or other biocides, which are harmful to the environment. MAISRC researchers aim to evaluate eco-friendly, biological coatings to reduce biofouling, control the spread of aquatic invasive species (AIS), and advance knowledge on zebra mussels.
This project is currently in its third phase. In this project period, MAISRC researchers conducted sequencing analysis, revealing that enzymatic coating formulations impact the microbial community population structure on surfaces; further analyses are ongoing. Researchers also characterized the UV resistance of these enzymes—a critical property to ensure they are suitable as coating additives—and are in discussion with the Bioresource Center to optimize the production process. They also investigated the attachment preferences of zebra mussels, confirming previous findings that coating type modulates attachment strength. MAISRC researchers found that the tested silicone coating base performed less effectively than an acrylic coating. This key finding will be further investigated and benchmarked against various coatings.
Samples were placed at various field sites, and multiple sets were collected over time for DNA analysis. These samples have been submitted for sequencing, and analysis is currently underway. Preliminary results from 16S rRNA sequencing data support earlier findings that enzyme treatments change the microbial communities on treated surfaces. For instance, at the Tonka Bay Marina site, the enzyme coating is observed to lower the microbial diversity on the surface and alter the makeup of the microbial community.
MAISRC researchers are studying how factors like biofilm community composition, quorum sensing (QS), nutrient availability, and substrate type and color influence zebra mussel (ZM) attachment. Previous research suggests that attachment strength may relate to substrate hydrophobicity, with ZMs showing a preference for less hydrophobic surfaces. In a recent experiment, researchers observed a ~6-fold increase in attachment strength on silicone coating (which is more hydrophobic) compared to acrylic, where most ZMs did not attach. To establish consistent experimental protocols, MAISRC researchers evaluated whether the location of ZM attachment on the Petri dish affects the measured attachment strength. Results indicate that ZMs attaching to the side of the plate appear to have weaker attachment, suggesting these samples may need to be excluded to ensure accurate measurements and reliable analysis.