A novel cold-active glycerophosphodiester phosphodiesterase and its application in whole-cell catalytic degradation of diphenyl phosphate at low temperature

As the organophosphate ester (OPE), diphenyl phosphate (DPhP) has been detected in various environments. The key enzyme glycerophosphodiester phosphodiesterase (GDPD) responsible for degrading DPhP was cloned and expressed from Psychrobacter sp. NJ358 (referred to as PsGDPD). Subsequently, PsGDPD exhibited optimal activity at 25 °C and possessed cold-active structural characteristics. In order to break down the barrier of intracellular enzyme transport and broaden its application, the engineered bacteria BL21/pET-InaKN-PsGDPD featuring well-preserved outer membrane integrity was constructed through the novel ice nucleoprotein (INP) cell surface engineering. Then, engineered bacteria were made into whole-cell catalysts, maintaining 68.5 % and 52.1 % relative activity after 8 times catalytic cycles and 7 days of storage at 10 °C. Notably, 0.5 mg L⁻¹ DPhP was extracellularly degraded by the whole-cell catalysts at 10 °C after 48 h. Therefore, whole-cell catalysts developed using BL21/pET-InaKN-PsGDPD represent a promising and eco-friendly strategy for the degradation of DPHP in low-temperature environments.