Paracoccus versutus KS293 adaptation to aerobic and anaerobic denitrification: Insights from nitrogen removal, functional gene abundance, and proteomic profiling analysis.

A novel strain KS293 exhibiting excellent aerobic and anaerobic denitrification performance was isolated and identified as Paracoccus versutus KS293. Nitrate nitrogen and total organic carbon could be effectively removed by P. versutus KS293 without nitrite accumulation, whilst 82% and 85% of total nitrogen was converted into gaseous products under aerobic and anaerobic conditions (P > .05), respectively. Based on the ratio of anaerobic to aerobic, relative abundance values were increased 1.41, 1.45, and 2.31 folds for nirS, nosZ, and narG, respectively. A comparison of the two-dimensional gel electrophoresis and principal component analysis showed significant differences in proteomic profiles between aerobic and anaerobic conditions. In total, 78 proteins that displayed fluctuations in relative expression were observed. 10 proteins including nitrate reductase, maintenance of cell membrane (TolA), and RNA polymerase-binding transcription factor (DksA) were differentially expressed. These findings demonstrated that P. versutus KS293 was effective for nitrogen removal under aerobic or anaerobic conditions.