Extraction and Purification of LasA Enzyme from pseudomonas aeruginosa

Abstract

Staphylolycin is one of the important enzymes produced by Pseudomonas aeruginosa as a competitive way against other bacterial species such Staphylococcus aureus. Pseudomonas aeruginosa was isolated from 100  clinical specimens, including urine, wound, and burn swabs. On Tryptic soya agar with heat killed Staphylococcus aureus at temperature 100°C, the capacity of local isolates to produce staphylolysin enzyme was investigated. Staphylolysin  enzymes A and D activity  was  determined  by  measuring  the  capacity  of  the  boiled Staphylococcus  aureus cells  of P.  aeruginosa culture  supernatants  for  lysis.

The results showed only two isolates from 23 P.aeruginosa isolates that were collected from patients suffering from burns and UTIs were shows positive production for Staphylolysin A (LasA), depending on the appearance of the transparent aura around its colonies the isolate no.1 was the most productive of this enzyme, as it formed a transparent halo of  about 14.16 mm, and Staphylolytic activity was extracted by cooling centrifugation and partially purified by ammonium sulphate precipitation at a saturation percentage of 80%, followed by Ion exchange chromatography using a Dowex-column  with purification folds and recovery of 4.3 fold, while SEC gave 1.5 fold.