Optimization of Halomonas Denitrification in Seawater Substrate

Abstract

This paper studied the effects of carbon source types, carbon-nitrogen ratio, pH and salt concentration on the denitrification of Halomonas bacteria under high-salt conditions to optimize the denitrification performance of mixed Halomonas bacteria. When the initial carbon source is glucose, the carbon to nitrogen ratio is 5:1, the pH is 7.2, and the salt concentration is 30 g/L, the maximum denitrification rate of mixed bacteria is only 19.92%. By optimizing the carbon source, the nitrogen removal rate can reach 69.25% at 72 h, which is about 49% higher than that before optimization. Under the optimal conditions with trisodium citrate as the carbon source, the carbon-to-nitrogen ratio is 5:1, the pH is 8 and the salt concentration is 60 g/L, the denitrification rate of the mixed bacteria in the seawater matrix is higher than before optimization 282%. Carbon source, carbon-nitrogen ratio, pH and salt concentration will all affect the denitrification of Halomonas bacteria. By optimizing them, it can greatly improve the denitrification of Halomonas bacteria under seawater substrate conditions.