Isolation, Identification and Genetics of Nylon6 Degrading Pseudomonas putida

Sixty-four soil samples (contaminatedwith nylon waste for many years) were collected from different places in Baghdad. From these samples, fortysevenisolates were obtained as a degrader for nylon6
film.These isolates were repeatedly tested in mineral salt medium supplemented withnylon6 film to ensure their degradation ability; only 27 isolates appeared tohave degradation ability fornylon6
filmas a sole source of carbon and nitrogen. These isolates (27 isolates) were screened for their ability to degrade nylon6 film according to growth density;it was found that these isolates were varied in their growth density. Themost efficient isolates were T1, M3, S3A, S12 andS17; however, S3A isolate is the best among them. Sixty-four soil samples (contaminatedwith nylon waste for many years) were collected from different places in Baghdad. From these samples, fortysevenisolates were obtained as a degrader for nylon6 film.These isolates were repeatedly tested in mineral salt medium
supplemented withnylon6 film to ensure their degradation ability; only 27 isolates appeared tohave degradation ability fornylon6 filmas a sole source of carbon and nitrogen. These isolates (27  solates) were screened for their ability to degrade nylon6 film according to growth density;it was found that these isolates were varied in their growth density. Themost efficient isolates were T1, M3, S3A, S12 andS17; however, S3A isolate is the best among them.According to growth density, 20 isolates were selected for identification; they were identified depending on morphological, cultural, and biochemical characteristics.Results showed that 16 isolates belonged toPseudomonas spp.(Pseudomonas putida (14) isolates, Pseudomonas stutzeri (1) isolate and Pseudomonas sp. (1) isolate, while the other four belonged toMoraxella spp. The plasmid profile for Pseudomonas putidaS3A was studied. Results showed that this isolate harbored small plasmid DNA bands.In order to study the role of its plasmid in degradation of nylon6 film, curing experiment was performed by using sodium dodecyl sulfate (SDS) and showed that two colonies had lost their ability to degrade nylon6 film as a sole source of carbon and nitrogen. Plasmid DNA extraction from one of these colonies indicated the loss of plasmid DNA bands, and this referred that the plasmid DNA bands could be responsible for degrading nylon6 film in P. putida S3A.