Assistant biology professor Kirwin Providence and biology major Sarah Kessler '09 presented a poster entitled, "Desmid Adhesion Mechanisms: A Prelude To Eukaryotic and Biofilm Formation" at the fifth annual Symposium in Plant Biology at the University of Massachusetts Amherst earlier this month.
Abstract:
Adhesion is a fundamental cellular process used by all kingdoms of life. The formation of biofilms (highly structured microbial communities) requires the secretion of adhesive substances. In many freshwater wetland ecosystems, photosynthetic algae (desmids) play important roles in the formation, structure, and function of biofilms.
Central to most adhesion processes is the production and secretion of extracellular polymeric substance (EPS). The EPS is a carbohydrate-rich matrix of molecules that is secreted beyond the cell wall. Previous research demonstrates that proteins are embedded in desmid EPS. This observation suggests that proteins (either independently, or in concert with EPS) may support cell binding to substrates.
Using the desmid Penium Margaritaceum as the model organism, we test the hypothesis that proteins mediate initial desmid-substrate binding. This binding event is important in that it is a prerequisite supporting the transitioning from the planktonic realm to biofilm formation and subsequent benthic community development.
We demonstrate that EPS-devoid cells are able to adhere to abiotic substrates. This binding is dependent on peripheral proteins associated with the desmid cell wall and/or plasma membrane. These observations increase our knowledge about this major group of microorganisms that may be keystone species in wetland habitats, and ones that profoundly affect environmental concerns such as water quality, pollution remediation, and disease control.
