Identification of substrates for Francisella novicida chitinases in order to characterize the importance of chitinase in biofilm formation

Abstract

Chitin is a polysaccharide, or a polymer that consists of many bound sugar monomers. It is a major structural component in crustacean exoskeletons as well as the cell wall of fungi. Chitin is broken down by chitinases, a class of enzymes that break the β-1,4 glycosidic bond that binds the sugar monomers. Chitinases are found in a variety of living things, including humans and bacteria. Notably, chitinase has been proposed to interfere with the biofilm formation of Francisella novicida (Fn), a biothreat bacteria characterized by the CDC. The goal of this experiment was to determine the effectiveness of various enzymes in breaking down Fn biofilm as well as determine an optional substrate for Fn chitinase (chiB) in order to better characterize the role of chitinase in biofilm regulation. It was found that chitinase from S. griseus decreased Fn biofilm in a statistically significant manner. Additionally, it was found that chiB was most effective at binding to 4-Nitrophenyl N,N′-diacetyl-β-D-chitobioside. We will continue to study chitinase’s regulation of biofilm, and further experimentation will be needed.