Biosynthesis of poly(3-hydroxybutyrate) by N,N-dimethylformamide degrading strain Paracoccus sp. PXZ: A strategy for resource utilization of pollutants

Abstract

N,N-dimethylformamide is a toxic chemical solvent, which widely exists in industrial wastewater. Nevertheless, the relevant methods merely achieved non-hazardous treatment of N,N-dimethylformamide. In this study, one efficient N,N-dimethylformamide degrading strain was isolated and developed for pollutant removal coupling with poly(3-hydroxybutyrate) (PHB) accumulation. The functional host was characterized as Paracoccus sp. PXZ, which could consume N,N-dimethylformamide as the nutrient substrate for cell reproduction. Whole-genome sequencing analysis confirmed that PXZ simultaneously possesses the essential genes for poly(3-hydroxybutyrate) synthesis. Subsequently, the approaches of nutrient supplementation and various physicochemical variables to strengthen poly(3-hydroxybutyrate) production were investigated. The optimal biopolymer concentration was 2.74 g·L-1 with a poly(3-hydroxybutyrate) proportion of 61%, showing a yield of 0.29 g-PHB·g−1-fructose. Furthermore, N,N-dimethylformamide served as the special nitrogen matter that could realize a similar poly(3-hydroxybutyrate) accumulation. This study provided a fermentation technology coupling with N,N-dimethylformamide degradation, offering a new strategy for resource utilization of specific pollutants and wastewater treatment.