Response of the aerobic denitrifying phosphorus accumulating bacteria Pseudomonas psychrophila HA-2 to low temperature and zinc oxide nanoparticles stress

• DOI: 10.1016/j.biortech.2022.127162
• Publication Date: 2022-04-13T15:33:28Z
• Authors: Kongyan Luo; Long Chen; Lei Du; Yuanyi Zhao; Qian Chen
• Keywords: Nitrogen; Temperature; Phosphorus; 01 natural sciences; 6. Clean water; Bacteria, Aerobic; Bioreactors; Pseudomonas; Denitrification; Nanoparticles; Zinc Oxide; 0105 earth and related environmental sciences

Performance and molecular changes of an aerobic denitrifying phosphorus accumulating bacteria Pseudomonas psychrophila HA-2 have been investigated under different temperatures and ZnO nanoparticles (NPs) exposures. Strain HA-2 removed 95.7% of total nitrogen (TN) and 24.6% of phosphorus at 10 °C, which was attributed to the joint up-regulation of intracellular energy metabolism and ribosome. Moreover, with the increase of ZnO NPs from 0 to 100 mg/L, TN and phosphurs removal efficiencies decreased from 95.7% to 44.5% and 24.6% to 6.8% at 10 °C, respectively, whereas phosphorus removal rate increased from 10.5% to 24.5% at 20 °C. Further transcriptomics and proteomics revealed that significant down-regulation of purine and amino acid metabolisms was the main reason for the inhibitory effect at 10 °C, while the up-regulation of antioxidant pathways and functional genes expressions was responsible for the promoted phosphorus accumulation at 20 °C. This study provides a potential solution for improving biological nutrients removal processes in winter months.