Fig. 7

Impact of nutrient enrichment and ethyl acetoacetate input on the planktonic cells and biofilm formation in Leptospira interrogans KeTo. Formation of planktonic cells of KeTo (bar with slant lines) in the absence of enrichment (light blue background) and the presence of enrichment (light green background) (a); Formation of biofilm of Keto (bar with slant lines) in the absence of enrichment (light blue background) and the presence of enrichment (light green background) (b); inset shows portion of microplates of corresponding treatment. The biofilm formed on microplate wells under various treatments was fixed with 99% methanol, stained with 0.1% crystal violet. The excess stain was removed by aqueous wash and dried. The dye was solubilized using 33% acetic acid and read at 570 nm. Error bar, mean (n = 6) ± SD. ****p < 0.0001; ns, non-significant. Asterisks placed over the horizontal line represents level of significance based on the t-test; *p < 0.05. 48 h old data. B, Basal EMJH without enrichment; B_KeTo, B inoculated with KeTo; B^ea, B containing ethyl acetoacetate; B^ea_KeTo, B^ea inoculated with KeTo; E, Enriched EMJH medium; E_KeTo, E inoculated with KeTo; E^ea, E containing ethyl acetoacetate; E^ea_KeTo, E^ea inoculated with KeTo.