Effects of Ion Combinations and Their Concentrations on Denitrification Performance and Gene Expressions of an Aerobic Strain Marinobacter Hydrocarbonoclasticus RAD-2

Salinity is one of the most important factors affecting nitrogen-removal efficiency denitrifying bacteria. A series different ion combinations and salinity gradients were carried out to clarify effects types concentrations on nitrogen removal by halophilic aerobic bacteria RAD-2. Nitrate concentrations, nitrite TAN OD600 monitored investigate their denitrification in each group. The results showed that Na+, K+, Cl- accelerated process improved at moderate additions, while Ca2+ Mg2+ no significant effect. Na+ was effective alone, K+ or needed be combined with least achieve similar efficiency. batch tests confirmed addition a concentration NaCl/Na2SO4 could effectively improve efficiency, excessive might hinder metabolism. In range 5~40‰, 5‰ dosage economical method for strain Real-time PCR experiments 17 key metabolism-related genes revealed chloride widely involved carbon metabolism microorganisms altering cell osmotic pressure opening channel proteins, thereby denitrification. this study may contribute better understanding roles various ions highlight importance control highly salted wastewater treatment.