원문정보
초록
영어
To alleviate oxidative stress generated during naphthalene metabolism, overexpression of antioxidant enzymes [Fpr (ferredoxin-NADP+ reductase) and SOD (superoxide dismutase)] was conducted in naphthalene-degrading bacterium Pseudomonas sp. strain As1. The fpr and sodA gene was placed under the transcriptional control of either constitutive lac promoter or native promoter. Both high performance liquid chromatography (HPLC) analysis and growth rate have shown that the recombinant cells effectively degraded naphthalene compared to wild type. All recombinant cells, except a strain As1(sodA), where sodA gene was up regulated by the lac promoter, exhibit more resistance to a superoxide generating agent, paraquat. Growth of As1(sodA) was inhibited by paraquat and its growth defect were significantly overcome by alkyl hydroperoxide reductase overproduction. Taken together, the data demonstrated that overproduction of these two genes contribute to oxidative tolerance during naphthalene degradation, however, more than necessary SOD, which may provoke generation of hydrogen peroxide, results in cell death.