Screening des enzymes hydrolytiques des bactéries du sol : essai d'optimisation

Abstract

This work aimed to the isolation and the search for hydrolytic bacteria from soil samples. The screening of the different hydrolytic activities (proteolytic, lipolytic, amylolytic and cellulolytic) on nutrient agar supplemented with various substrates: sklmmed milk, tween 80, starch and cellulose showed that 27 isolates had at least one hydrolytic activity, with the first three substrates; however, with cellulose no hydrolysis zone was detected. The isolate 41 was selected for its ability to produce three outstand.ing hydrolytic activities simultaneously. The study of microscopie, macroscopic and biochemical characters reveals that this strain belongs to the genus Bacillus sp. The results of enzyme assays after culturing on liquid media showed tbat the protease and the lipase are produced in high levels in the presence of corresponding substrates. In addition, the crude enzyme extract sbowed a detergent activity on red sauce stains.