TOTAL AMONIA NITROGEN REMOVAL ACTIVITY OF HETEROTROPHIC BACTERIA PSEUDOMONAS MONTEILII NTB-3 AND PSEUDOMONAS MOSSELII BF-1 ISOLATED FROM BIOFILTER SOURCES

• Main Author: Riptanto, Irsanda
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/79109
• Institution: Institut Teknologi Bandung

In recirculating aquaculture systems (RAS), biofilter is used to control the concentration of toxic ammonia (NH3) through the nitrification process. Despite the importance of their role, the slow-growing nitrifying bacteria constitute only a small fraction of the microbial community in biofilter. Meanwhile, heterotrophic bacteria dominate due to their capacity for removing carbon and nitrogen components from water, and their role is often overlooked. In this research, heterotrophic bacteria were isolated and their ability to remove total ammonia nitrogen (TAN) was tested in batch of 100 mL heterotrophic nitrifying medium (HNM). Pseudomonas sp. NTB-3 and Pseudomonas sp. BF-1 were isolated from activated freshwater nitrifying culture samples (NTB) and a freshwater biofilter installation (BF), respectively. Both strains were found to be able to remove TAN with average rates of each isolate were as follows: 0.98; 3.85; 4.64; and 1.93 (NTB-3), 4.11; 1.94; 2.22; and 1.73 (BF-1) (ppm/h) for initial TAN of 10 ppm, 20 ppm, 30 ppm, and 50 ppm, respectively. The TAN removal efficiency showed good values (>90%) for initial TANs of 10 ppm - 30 ppm, and an efficiency of 80% was achieved by both isolates at initial TAN of 50 ppm. The growth curve showed that NTB-3 had 10 times higher cell density and almost four times higher specific growth rate than BF-1. Evaluation of the removal activity in a 900 mL batch showed similar performance between NTB-3, BF-1, and NTB-3:BF-1 consortium (1:3) with average of total TAN removed (37,3 ppm), average removal rate (3,11 ppm/h), and carbohydrate utilization (224 ppm). During the experiment, NO2--N and NO3--N concentrations were found to below the safe limit of 0.05 ppm and 1.0 ppm respectively, for the aquaculture system. The two heterotrophic bacteria showed potential in TAN removal that could be applied in the aquaculture system without toxic accumulation of nitrite and nitrate in the future.