Schematic representation of bacteria in a biofilm

Schematic representation of bacteria in a biofilmSchematic representation of bacteria, shown as rods, in a biofilm. While the wild-type strain in the top row possess all genes, one gene is deleted in the mutant. A mutant library contains about 6000 mutants; one for each gene in the genome of Pseudomonas aeruginosa. The wild-type survives the stress imposed by the antibiotic and the antimicrobial coating, while the mutant does not. This means that the gene deleted in the mutant is required for stress survival Source: Jules Valentin, EMPA