Using 3,4-dichlorobenzoic acid as growth substrate by Brevibacterium Group B: Effect of some growth
- Details
- Category: Biological Sciences
- Published: Tuesday, 08 May 2012 03:00
- Written by Haya Hamed Allawi
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Abstract
Using 3,4-dichlorobenzoic acid as growth substrate by Brevibacterium Group B: Effect of some growth conditions.
Haya Hamed Allawi
Mu’tah University, 2010
Different substrate concentrations of 3,4-CBA were tested for biodegradation by Brevibacterium Group B. The higher degradation percentage was 1 mM concentration and the maximum degradation percentage of 3,4-CBA was accomplished in 20 hours period. Different incubation temperatures of 25, 30, 37 and 42 ºC were examined their effect on the biodegradation of 3,4-CBA, we found the optimal degradation occur at 37 ºC. The Brevibacterium Group B cells optimally degrade the 3,4-CBA at a pH of 8. These cells were carbon starved fore two periods; 24 and 48 hours. The 3,4-CBA degradation by carbon-starved cells for 48h was more helpful than that of 24 h starved and nonstarved cells, respectively.
When our isolation was pre-starved for 24 and 48 h, the degradation ability of 3,4-CBA had clearly commenced after a shorter acclimation period, become slightly faster, and the endpoint (final degradation percentage) was accomplished in a shorter time, compared with that of the non-starved cells.
The optimum conditions were tested together to show the maximal biodegradation percentage, cell growth and therefore Cl release. The adaptation of Brevibacterium Group B cells was clearly shown to be crucial aspect for better degradation ability. It is clearly shown that the 1,2-dioxygenase activity-dependent-ortho cleavage pathway for 3,4-CBA substrate is the only option.