Bacterial Strain Improvement for Bioremediation.
Abstract
The gene (vgb) for the bacterial hemoglobin from Vitreoscilla has been cloned in Burkholderia strain DNT which can degrade 2,4-dinitrotoluene (DNT). The new strain,I YVl, expressed vgb, grew better, survived longer, and degraded DNT faster than - strain DNT. The addition of surfactants and succinate or yeast extract also stimulated DNT degradation up to 99.5%. Measurements of the oxygen kinetics for DNT degradation showed that for all strains the kinetics of oxygen uptake were bip- hasic but could be resolved into two components. Purified VHb added to cell-free extracts of strain DNT stimulated DNT degradation, but not control bovine Rb. Regarding biodegradation of DNT in a soil slurry spiked with DNT, YVl showed a slightly higher degradation rate (ranging from 5 to 18%). When vgb was cloned into E.coli containing the gene for DNT dioxygenase the resultant strain exhibited - enhanced growth, viability, and degraded twice as much DNT under low aeration condi- tions. DNT dioxygenase has been partially purified by gel chromatography; it requir%. NADIl, is stimulated by phospholipids, and inhibited at high ionic strength. Probin the oxygen binding site of VHb using site-directed mutagenesis showed%that the residue GlnE7 was not involved in stabilizing the bound oxygen.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 31, 1998
- Accession Number
- ADA343644
Entities
People
- Dale A. Webster
Organizations
- Illinois Institute of Technology