Efficiency of naphthalene and salicylate degradation by a recombinant Pseudomonas putida mutant strain defective in glucose metabolism

Metabolically engineered microorganisms may have tremendous potential in re moving toxic compounds from nature. In general, microorganisms prefer to ut ilize simpler carbon sources over toxic compounds when both are present in an environment and, therefore, the presence of simpler carbon sources may g reatly reduce the efficiency of a microorganism towards toxic compounds. If a microorganism is prevented from utilizing simpler carbon sources, thereb y making it totally dependent upon the toxic compounds, it should increase the specificity for and efficiency of degradation of the toxic compounds in the presence of other, simpler carbon sources. To test this hypothesis, th e efficiency of naphthalene and salicylate degradation in the presence of g lucose by a recombinant Pseudomonas putida strain mutated in glucose metabo lism was determined and compared to the nonmutated strain. Results obtained indicate that the impairment of glucose metabolism leads to better degrada tion of naphthalene and salicylate in the presence of glucose.