Tuesday, April 20, 2010
8-64

Application of cellulolytic biofilms: The effect of cell surface hydrophobicity

Vladimir Jirku, Jitka Hrdinova, Lucie Kriklavova, Gita Prochazkova, Tereza Krulikovska, Alena Cejkova, and Jan Masak. Fermentation chemistry and bioengineering, Institute of Chemical Technology, Technicka 5, Prague 6, 166 28, Czech Republic

Cellulolytic microorganisms are mostly provided with cell surface multiprotein complexes including substrate-targeting and hydrolytic components, efficiently delivering enzymatic component to the cellulose, if such a solid substrate is physically contacted by cell surface. Therefore, a progress in establishing more efficient arrangement for technological solubilization of solid cellulosic wastes could be achieved using cellulolytic biofilms, formed by direct colonization of these wastes by cell populations of cellulolytic strains of adequate properties. However, the primary contact between microbial cell and solid substrate is generally mediated by nonspecific, binding interactions. In this connection, the effect hydrophobicity  of the outermost  cell surface on biofilm formation was investigated using cellophane as a model cellulosic carrier and image analysis to quantify biofilm structure (heterogeneity). The experiments with different cellulolytic strains were conducted to  elucidate the effect of cultivation conditions on cell hydrophobicity and cellulase activity if different cellulosic substrates were utilized. Hydrophobicity values were shown to be useful predictor of cellulolytic biofilm behavior and activity.