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Exploited Application of a Newly Isolated Pseudomonas acidovorans XII in Microbial Degradation of 1-Chloro-4-Nitrobenzene

Maulin P Shah

International Journal of Environmental Bioremediation & Biodegradation. 2014, 2(2), 75-83 doi:10.12691/ijebb-2-2-5
  • Figure 1. Putative initial reactions with 1C4NB based on studies of nitroben-zene degradation bia catechol (40) or 2-aminophenol (30),nitrobenzene trans-formation into aniline (34),reducative dehalogenation (13),and dehalogenation due to hydrolytic (25) or dioxygenolytic (32) activity
  • Figure 2. Growth of bacterial strain XII with 1C4NB as the sole carbon source.The initial concentration of the dissolved carbon source in the culture fluid was 1.2 mM. The culture was inoculated (10%, vol/vol) with a preculture grown with 1C4NB and harvested during the exponential phase. Substrate depletion, formation of chloride, and TOC values were determined as described in Materials and Mdthods.Growth was monitored by monitoring the increase inOD546
  • Figure 3. Time course for conversion of 1C4NB by resting cells of strain XII grown with 1C4NB under aerobic conditions. Cell suspensions at OD546 of 6.0 was added to a final concentration of 1.36 mM. Substrate depletion was determined by HPLC
  • Figure 4. Time course for conversion of 1C4NB by resting cells of strain XLL grown with 1C4NB under anserobic conditions. Cell suspensions at an OD546 or 5.0 were resuspended in 50 Mm sodium phosphate buffer (pH 7.2). Substrate was added to a final concentration of 1.2 mM. Substrate depletion and product formation were determined by HPLC
  • Figure 5. Spectral changes due to 2-amino-5-chlorophenol 1,6-dioxygenase activity in extracts of cells pregrown with 1C4NB. (A) Reaction mixture containing 2-amino-5-chlorophenol (100 uM) and XII cell extract (0.1 mg of protein) in 1 mi of 50 mM sodium phosphate buffer (pH 7.2). (B) Reaction mixture also containing NAD (100 uM). Overlay spectra were recorded for 6 min from 220 to 450 nm as indicated
  • Figure 6. Proposed pathway for catabolism of 1C4NB by bacterial strain XII. The ring cleavage product 2-amino-5-chloromuconic semialdehyde can be subject to dehydrogenation (probably producing 2-amino-5-chloromuconic acid) or intramolecular condensation to form the dead-end product 5-chloromuconic acid as previously reported for 2-aminophenol transformation by P. pseudoalcaligenes JS45 (20) or by Pseudomonas sp. strain AP-3 (48)