Nutritional effects on colony size and biofilm formation of Xylella fastidiosa growing on simple chemically-defined media

• Author(s): Andersen, Peter; Ishida, Maria Lucia; Leite, Breno;
• Abstract: We tested two hypotheses: 1) growth of Xylella fastidiosa (Xf) requires a smaller number of compounds than in currently available chemically defined media, and; 2) colony size and biofilm formation of X. f. are influenced by nutrients. New defined media were developed and evaluated for three strains of X. f. New defined media were compared to PW+ medium and to XF-26 (defined medium), in agar and liquid culture. A simple medium consisting of 5 organic compounds and 3 inorganic salts supported growth of X. f. Media were formulated based on the chemistry of the xylem fluid of a PD-susceptible Vitis genotype. The performance of X. f. was dependent on the strain, media composition and strain*media interactions. Results support the contention that the chemistry and the xylem fluid of media can affect the behavior of X. f. New formulations increased the capacity of X. f. to form biofilm and reduced the number of cells in the planktonic state. One medium contained reduced glutathione as an ingredient. The importance of this antioxidant in aggregation, biofilm formation and survival will be discussed.
• Publication Date: Jun 2003
• Journal: Phytopathology