Genetics and Regulation of Nitroaromatic Hydrocarbon Degradation.
Final rept. 15 Jun 94-14 Sep 97
COOK COLLEGE NEW BRUNSWICK NJ CENTER FOR AGRICULTURAL MOLECULAR BIOLOGY
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Catabolic pathways for nitroaromatic compound degradation that are initiated by reductive or monooxygenase enzymes are being examined at the molecular level. The gram negative P. fluorescens strain ENV2O3O degrades p-nitrophenol oxidatively via hydroquinone. All of the genes for this catabolic pathway have been cloned and their nucleotide sequence determined. Two genes encoding for regulatory proteins have been identified. The P. fluorescents ENV2O3O cloned genes have been shown to hybridize with genomic DNA from other p-nitrophenol degrading strains P. putida JS444 and moraxella species strain lA. The genes for p-nitrophenol degradation have been cloned from P. putida JS444. A comparison of the genes from ENV2O3O and JS444 shows that although they are 80-90 identical a gene for a key regulatory protein is missing. This explains the differences seen in how the metabolism of p-nitrophenol is regulated in the two strains. The gram negative P. pickettii strain YHlO5 degrades p-nitrobenzoate and p-aminobenzoate reductively via protocatechuate. The genes for the degradation of p-nitrobenzoate have been cloned and their nucleotide sequence determined. A regulatory gene has been identified. The gram negative strains P. syringae HYlOl and P. putida YH102 also degrade p-nitrobenzoate by a reductive route but genomic. DNA from these two strains does not cross hybridize to the genes cloned from p. pickettii YHlO5, indicating diversity in the gene sequences. The genes for p-nitrobenzoate degradation have been cloned from YHlOl and HYIO2 and shown to be very similar to each other. The cloned YH1O2 genes have been sequenced and the results show that although the HY1O2 and HY1O5 genes are 50-60 identical they are organized quite differently.
- Genetic Engineering and Molecular Biology