Compounds including organophosphorus pesticides (OPs) and chemical
nerve agents are toxic compounds synthesized recently which disrupt the mechanisms of neural transmission. Therefore, a critical requirement is the development of a bio-refining technology to facilitate the biodegradation of organophosphorus
pollutants. The diisopropylfluorophosphatase (
DFPase, EC 3.1.8.2) from the
ganglion and brain of Loligo vulgaris acts on P-F bonds present in some OPs. Intracellular production of OPs-degrading
enzymes or the use of native bacteria and fungi leads to a low degradation rate of OPs due to a mass transfer issue which reduces the overall catalytic efficiency. To overcome this challenge, we expressed
DFPase on the surface of E. coli for the first time by employing the N-terminal domain of the
ice nucleation protein (InaV-N) as an anchoring motif. Tracking the
recombinant protein confirmed that
DFPase is successfully located on the outer membrane. Further studies on its activity to degrade
diisopropylfluorophosphate (
DFP) showed its significant ability for the biodegradation of
diisopropylfluorophosphate (
DFP) with a specific activity of 500 U/mg of wet cell weight. Recombinant cells could also degrade
chlorpyrifos (Cp) with an activity equivalent to a maximum value of 381.44 U/ml with a specific activity of 476.75 U/mg of cell, analyzed using HPLC technique. The optimum activity of purified
DFPase was found at 30 °C. A more increased activity was also obtained in the presence of
glucose-
mineral-
salt (GMS) supplemented with tryptone and 100 mg/L Co(2+) ion. These results highlight the high potential of the InaV-N anchoring domain to produce an engineered bacterium that can be used in the bioremediation of
pesticide-contaminated environments.