Biosorption of Heavy Metals by the Locally Isolated Pseudomonas spp.

number: 
2215
إنجليزية
Degree: 
Author: 
Israa Abd Mohammed Ganem
Supervisor: 
Dr.Hameed M.Jasim
year: 
2008

 A total of 110 samples were collected from different environments (waste waters, soil, and fresh waters) and locations in Baghdad governorate. Total isolates obtained from these samples were 85, 42 of them were suspected to be Pseudomonas spp. depending on their stability to grow on cetrimide agar. Biochemical tests have been done on these suspected isolates, these biochemical tests include catalase test, oxidase test, gelatin hydrolyses test and the ability of these isolate to grow on king A agar and king B agar medium, which give a positive results for catalase and oxidase tests for all isolates, also a positive results for gelatin hydrolyses test, while for isolate growing on king A and king B give a variable results. Ability of these isolates to resist heavy metal (nickel, cobalt, lead and zinc) was examined by using plate diffusion method. Pseudomonas isolates exhibited different resistant pattern depending on the various concentration of metals. However, an isolate of Pseudomonas spp. namely P36 was the most resistant to nickel and zinc, while another isolate P37 was resistant to cobalt, and for lead isolate no.41.Optimum conditions for biosorption of the locally isolated Pseudomonas spp. P36 were studied. Results showed that the optimum biosorption conditions were; pH 7.0, temperature 25ºC, biomass concentration 0.5gm/L, initial metal concentration 20 mg/L, biomass age was 2 days, contacting time was 100 minutes, and agitation rate was 150 rpm.