Synthetic biofilm community for efficient phosphorus removal from high-salinity wastewater

Abstract

Substantial amounts of phosphorus are discharged into water bodies, leading to an urgent need to develop methods for phosphorus removal. Here, 12 novel polyphosphate-accumulating organisms were identified from marine biofilms through genomic screening and incorporated into a stable community for phosphorus removal from high-salinity water. The synthetic biofilm community achieved an 82% removal efficiency in a marine broth medium. Electron microscopy showed storage of polyphosphate particles in the bacterial cells. Metatranscriptomic analysis indicated expression changes of genes for phosphate transport, as well as relevant metabolic pathways. In particular, pst genes encoding transporters with high phosphate affinity were downregulated at high-phosphorus concentration, whereas pit genes encoding transporters with low phosphate affinity were constitutively expressed. Furthermore, the synthetic biofilm community exhibited remarkable efficiency in removing over 92% of phosphorus from fish farming facility wastewater. Taken together, synthetic community using marine biofilm bacteria is a new strategy of phosphorus removal.