S-oph enzyme for efficient degradation of Polyvinyl alcohol: Soluble expression and Catalytic properties

Abstract

Abstract Background Polyvinyl alcohol (PVA) is one of the most widely used water-soluble polymers with great mechanical properties. However, water-soluble polymers are one of the major organic pollution sources in streams, river, and marine ecosystems. Once dispersed in aqueous systems, they can directly interfere with the life cycle of aquatic organisms due to their direct toxicity. Therefore, it is urgent to develop efficient microorganisms or enzyme to degrade it. The oxidized PVA hydrolase (OPHase) plays an important role in the pathway of PVA biodegradation. It is the key enzyme in the second step of PVA completely degradation. Methods and Results The s-oph gene was cloned from laboratory isolated strain Sphingopyxis sp. M19. The s-oph gene was expressed in the E. coli system pET32a/s-oph expression vector in the form of an inclusion body. By binding with the molecular chaperone, pET32a/s-oph/BL21 (DE3)/pGro7 was constructed successfully, which enabled the s-oph gene to achieve soluble expression in E. coli. The s-oph gene expressed protein was purified at the yield of 16.8 mg L− 1, and its catalytic activity reached 852.71 U mg− 1. In the s-oph enzyme reaction system, the degradation efficiency of PVA can be increased to 233.5% compared to the controls. Conclusion The s-oph enzyme had PVA degradation characteristics, high efficiency, specificity, and stability. The s-oph enzyme has good practical application potential in alleviating plastic pollution and protecting the environment.