EFFECT OF PSEUDOMONAS AERUGINOSA EXOMETABOLITES ON PLANKTONIC AND BIOFILMCULTURES OF ESCHERICHIA COLI

Aim. Study the effect of P. aeruginosa exometabolites on planktonic and biofilm cultures of bioluminescent
E. coli strain. Materials and methods. E. coli K12 TG1 (pF1 lux+ Apr) recombinant bioluminescent strain, P.
aeruginosa АТСС 27853 reference strain and 2 nosocomial isolates were used. Pyocyanin and pyoverdin
content in supernatant of P. aeruginosa over-night cultures was evaluated according to E. Deziel et al. (2001).
Planktonic and biofilm cultures of E. coli were obtained in 96-well plates (LB, statically, 37C), optical density
of plankton, film biomass (OD600, OD580) and bioluminescence in plankton and biofilm were evaluated
in microplate reader Infiniti M200 (Tecan, Austria). Results. P. aeruginosa exometabolites increased the
duration of lag-phase in E. coli, and short term exposition inhibited luminescence of planktonic cells. These
effects are determined by bactericidal action of pyocyanin and pyoverdin. Supernatants of over-night cultures
of P. aeruginosa inhibit formation of biofilm and disrupt the formed biofilm of E. coli. Effect of pyocyanin
and pyoverdin on these processes is not established, other factors may have higher significance. Conclusion.
Bioluminescence of E. coli K12 TG1 that reflects the energetic status of the cell allows to evaluate and prognose
the character of coexistence of P. aeruginosa in combined with E. coli planktonic and biofilm culture.

Pseudomonas aeruginosa, Escherichia coli, Pseudomonas aeruginosa, Escherichia coli, biofilm formation, exometabolites, bioluminescence