Biofilm formation by adhesin mutants. (A to D) Quantification of biofilm formed by WT P. fluorescens Pf0-1, ΔlapA and ΔmapA single mutants, and the ΔlapA ΔmapA double mutant after 6 h of growth in K10-T medium (A), 16 h of growth in K10-T medium (B), 6 h of growth in KA medium (C), and 16 h of growth in KA medium (D). For statistical tests, hypothesis testing was conducted in GraphPad Prism 8 using two-tailed t tests. P values are indicated by asterisks as follows: *, P < 0.05; **, P < 0.01; ***, P < 0.001; nonsignificant (ns), P > 0.05. (E) Representative image of biofilm formed by WT P. fluorescens Pf0-1 and ΔlapA, ΔmapA, and ΔlapA ΔmapA mutants after 16 h of growth in the indicated medium and stained with 0.1% (wt/vol) crystal violet.