Etude de l’effet de la température et du pH sur l’activité antimicrobienne des métabolites secondaire sécrété par Pseudomonas aeruginosa isolé des sols salins.

Abstract

Pseudomonas aeruginosa is a gram-negative bacterium that live in soil, plants and water surfaces. The aim of our study is to extract from two secondary metabolites (pyocyanine and pyoverdine) secreted by Pseudomonas aeruginosa and to study the antimicrobial effect of pyocyanin against pathogenic microorganisms. Liquid medium King A and B extract these two substances with chloroform and methanol. The purified pyocyanin pigment has been subjected to antibacterial activity to pathogens such as S. aureus, E. coli, C. albicans, B. cereus and Salmonella sp using the disk diffusion method. The study found that pyocyanin showed significant antimicrobial activity against test pathogens. The study of the compositional variation of the culture media and the deferent temperatures revealed an ideal relationship between the temperature increase and the pH concentration of the medium. The best production of pyocyanin was detected on the King A medium of pH 7 at 45.51μg/ml at a temperature of 28°C.And better production of pyoverdine was detected on the King B medium of pH 7 at a rate of 60 μg/ml at a temperature of 37°C.