Bacterial Strain Improvement for Bioremediation

摘要

The gene (vgb) for the bacterial hemoglobin from Vitreoscilla has been cloned inBurkholderia 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