Cloning and characterization of genes involved in bioremediation from nocardioform bacteria
Lemaire, Peter Amponsah
The alarm ing incidence of pollution arising from technological advancement has attracted much concern worldwide. Bioremediation has been considered promising to offer cost-effective, pollution-free and economically feasible means of removing pollutants from the environment. Within this framework, it was desired to clone and characterize genes responsible for two bioremediations, viz cesium accumulation and benzoate degradation. Genomic library of Rhodococcus erythropolis CS98 was constructed, using shuttle vector pDA71, in Escherichia coli strain MM294-4 and the pool of recombinant plasmids of this library transformed into Rhodococcus strain SQL The transformants were screened for acquired ability to utilize benzoate as sole carbon source. Various genomic libraries were also screened for tolerance to high concentrations of NaCl. Three different gene inserts of sizes 2.8kb, 3.7kb and 31.8kb were identified from mutants with acquired ability to degrade benzoate. Meanwhile, genomic library of CS98 in strain SQ1 had clones that could confer osmotolerance phenotypes. CS98 therefore, bears genes responsible for benzoate degradation and osmotolerance. Genomic libraries of Nocardia brasiliensis, Mycobacterium avium, Rhodococcus australis A448 and Rhodococcus rhodochrous ATCC 12674 all had clones that could confer osmotolerance phenotypes.