Isolation and identification of agar degrading bacteria and study of the genetic nature of this characteristic. +CD

number: 
1291
إنجليزية
Degree: 
Imprint: 
Biotechnology
Author: 
Hiba Abd Alkader Al-Najjar
Supervisor: 
Dr. Abdul Kareem Abdul Razak Al-Kazaz
year: 
2006
Abstract:

Forty different samples (water and soil) were collected from different places in Iraq and Syria, 25 isolates were isolated from these samples which have the ability to grow on agar plate (defined media). These isolates were cultured again on agar plate (defined media) then only 12 isolates showed the ability to degrade agar by growing and forming clearing zone around the bacterial growth. These isolates were identified by morphological and biochemical tests and the results showed that 8 isolates belong to Pseudomonas and 4 isolates belong to Bacillus and designated as (HA1-HA12). Screening was done for the 12 isolates that show the ability to grow and degrade agar as a sole carbon source to select the efficient bacterial isolate depending on clearing zone around the bacterial growth and found the (HA1) was the best isolate for Pseudomonas and (HA9) for Bacillus. Genetic studies of agar degradation property for choosing isolates of Pseudomonas (HA1) and Bacillus (HA9) was done by studying the plasmid profiles for both isolates and the result showed that both isolates have a small plasmid DNA bands using salting out method. Curing experiments by SDS indicated that pseudomonas (HA1) had lost their ability to grow on agar as a sole carbon source, while in Bacillus (HA9) didn't loss their ability to degrade agar. These results were confirmed that agar degredative property was plasmid-encoded in Pseudomonas (HA1) while in Bacillus was chromosomal. Transfer the agar degradation property from Pseudomonas (HA1) to E. coli MM294 by transformation was succeeded.