Potential of pseudomonas aeruginosa environmental isolates for biofilm formation

Abstract

Biofilm formation is one of the main characteristic of Pseudomonas aeruginosa strains. This ability provide bacteria to survive in different, usually restrictivesss environmental conditions. In the same time, biofilm forming is a risk in a many field of industry, mainly in food industry. It is known that diverse P. aeruginosa strains from various environmental sources have different potention to form biofilms. In this paper it is examinated the potention to form biofilm four isolates of P. aeruginosa and based of this results, tested isolates have classificated into four groups. Biofilm formation tested in microtitar plates during the 24 hours at changed conditions of temperature (37°C and 22°C), pH (6 and 7) and concentration of NaCl (1% and 2%). Obtained results have shown that isolated P. aeruginosa have unsimilar ability to form biofilms. Biomass of formed biofilm was greater at 22°C than at 37°C. Also, acid conditions and higher concentration of salt had no inhibitory effect to biofilm forming process.

Stvaranje biofilmova predstavlja jednu od glavnih osobina Pseudomonas aeruginosa koja omogućava ovoj bakteriji preživljavanje u različitim, često nepovoljnim uslovima životne sredine. Međutim, formiranje biofilmova predstavlja i faktor rizika u mnogim oblastima industrije, posebno prehrambene, pošto prisustvo čvrstih površina pruža dobre uslove za formiranje biofilma. Kako je poznato da izolati P. aeruginosa koji potiču iz različitih uzoraka poreklom iz životne sredine imaju različit potencijal da formiraju biofilmove, u ovom radu je ispitana sposobnost formiranja biofilmova četiri izolata ove bakterije i izvršena njihova klasifikacija u odnosu na ovu osobinu. Primenjen je statički test u mikrotitar pločama u trajanju od 24 sata u različitim uslovima temperature (37°C i 22°C), pH (6 i 7) i koncentracije NaCl (1 i 2%). Dobijeni rezultati su pokazali da izolati P. aeruginosa imaju različitu sposobnost da formiraju biofilmove, da je masa formiranih biofilmova bila veća na 22°C, kao i da promenjeni uslovi sredine nisu inhibirali stvaranje biofilmova.