Résumé:
Pseudomonas are microorganisms widely distributed in various environments, they are ubiquitous bacteria. They produce many secondary metabolites with antimicrobial effects against different pathogens, which are responsible for different infections. They also produce enzymes that can be used in several industries such as dairy, sugar, textile, paper, pharmaceutical, food products, oil and fat production. In this work we have tried to look for some metabolites and enzymes produced by Pseudomonas in seawater. Eight isolates were belonged to Pseudomonas fluorescens and used in an antagonism test against E.coli, S.aureus, P.aeruginosa and C.albicans on Mueller-Hinton and King B medium. These isolates were cultured in NaCl concentrations of 0.5%, 2.5%, 7% and 9% and subsequently used in showing its production of lipases, amylase and proteus .
The results of this study show that the 8 Pseudomonas weakly inhibited the test strains. The zones of inhibition vary from 0 to 2 cm in diameter, including one isolate (3) which showed an effect on all the target strains with a relatively remarkable inhibition of 2 cm in diameter against Candida albicans.
Salt tolerance results indicate a strong growth of isolates in 0.5% and 2.5% NaCl concentrations and a gradual decline in growth to 5% until it becomes difficult to observe at 7% and 9%. The study of enzyme activity revealed lipase production by isolate (9), amylase production by isolate (3) and protease production by isolate (10).
