Characterization of Pseudomonas sp. LS3K as Nitrate Removal Agent at Different C/N Ratios Under Aerobic Condition

Abstract

This study aimed to determine the characteristics of growth kinetics and the nitrate removal ability by Pseudomonas sp. LS3K on synthetic medium at different C/N ratios. This research was conducted by growing Pseudomonas sp. LS3K in denitrification medium under aerobic condition. The nitrogen source on the medium was sodium nitrate, and the carbon source was trisodium-citrate-dihydrate. The C/N ratios in the medium were adjusted to 5, 10, 15 and 20. The bacterial growth characteristic was observed based on the increases in the optical density value. Characteristics of nitrate removal by Pseudomonas sp. LS3K was observed based on the nitrate removal (NO3) and nitrite (NO2) production during the observation. The results showed that Pseudomonas sp. LS3K had the ability to grow in the medium with different C/N ratios and perform aerobic denitrification by reducing nitrate to nitrite. Themost nitrate removal ability of Pseudomonas sp. LS3K was found in the medium with C/N ratio 10 resulting nitrate removal of 299 {\textpm} 16.43 mg L−1 with the removal rate of 6.208 {\textpm} 0.34 mg L−1 per hour, removal efficiency of 98.350{\%} {\textpm} 0.40{\%} from the initial nitrate concentration and gave minimal nitrite production.