Metabolic Engineering of Pseudomonas putida KT2440 for Complete Mineralization of Methyl Parathion and γ-Hexachlorocyclohexane

Agricultural soils are often cocontaminated with multiple pesticides. Unfortunately, microorganisms isolated from natural environments do not possess the ability to simultaneously degrade different classes of pesticides. Currently, we can use the approaches of synthetic biology to create a strain endowed with various catabolic pathways that do not exist in a natural microorganism. Here, we describe the metabolic engineering of a biosafety Pseudomonas putida strain KT2440 for complete mineralization of methyl parathion (MP) and γ-hexachlorocyclohexane (γ-HCH) by functional assembly of the MP and γ-HCH mineralization pathways. The engineered strain was genetically stable, and no growth inhibition was observed. Such a strain not only would reduce the toxicity of MP and γ-HCH but also would prevent the accumulation of potentially toxic intermediates in the environment. Furthermore, expression of Vitreoscilla hemoglobin improved the ability of the engineered strain to sequester O2. The inoculation of the engin...