Hydrophobic nature and effects of culture conditions on biofilm formation by the cellulolytic actinomycete <em>Thermobifida fusca</em>

Abstract

<em>Thermobifida fusca</em> produces a firmly attached biofilm on nutritive and non-nutritive surfaces, such as cellulose, glass, plastic, metal and Teflon^&reg;. The ability to bind to surfaces has been suggested as a competitive advantage for microbes in soil environments. Results of previous investigations indicated that a Gram-positive cellulolytic soil bacteria, <em>Cellulomonas uda</em>, a facultative aerobe, specifically adhered to nutritive surfaces forming biofilms, but cells did not colonize non-nutritive surfaces. Cell surface hydrophobicity has been implicated in the interactions between bacteria and the adhesion to surfaces. It was recently described that the cellulolytic actinomycete <em>T. fusca</em> cells hydrophobicity was measured and compared to the cellulolytic soil bacteria <em>C. uda.</em> Also, <em>T. fusca</em> biofilm formation on non-nutritive surface, such as polyvinyl chloride, was examined by testing various culture ingredients to determine a possible trigger mechanism for biofilm formation. Experimental results showed that partitioning of bacterial cells to various hydrocarbons was higher in <em>T. fusca</em> cells than in <em>C. uda</em>. The results of this study suggest that the attachment to multiple surfaces by <em>T. fusca</em> could depend on nutrient availability, pH, salt concentrations, and the higher hydrophobic nature of bacterial cells. Possibly, these characteristics may confer <em>T. fusca</em> a selective advantage to compete and survive among the many environments it thrives.