- Disruption of Xylella fastidiosa CVC gumB and gumF genes affects biofilm formation without a detectable influence on exopolysaccharide production. Souza, L.C., Wulff, N.A., Gaurivaud, P., Mariano, A.G., Virgílio, A.C., Azevedo, J.L., Monteiro, P.B. FEMS Microbiol. Lett. (2006)