Nitrite Transformation using Microbial Consortium

High concentrations of nitrite and nitrate are commonly observed in aquaculture wastewater and are recognized as a major environmental concern. Sustainable aquaculture faces challenges avoiding environmental damages. In recent years, removal of nitrogen waste has become a key focus worldwide. Therefore, a safe, environment friendly and economically feasible method is very essential to treat nitrite, nitrate that are toxic and cause harmful effects on the aquatic ecosystem. This study addresses the pressing challenge of nitrogen waste management in aquaculture wastewater by evaluating the transformation ability of two nitrite-oxidizing bacterial strains (NOB 1 and NOB 2) and their consortium. At an initial nitrite concentration of 2 mg l-1, NOB 2 achieved (62.3 % ± 5.1) removal efficiency as compared to NOB 1 (56.9 % ± 4.5), whereas at 10 mg l-1, NOB 2 was found (92.0 % ± 5) and NOB 1 shown higher transformation efficiency than NOB 2 with (95.6 % ± 3.6). This showing that the dependency of this NOB 1 and NOB 2 on selective nitrite as a substrate. Next, the microbial consortium showed a stoichiometric transformation of nitrite to nitrate at both lab-scale (82.8 % ± 4.5) and in-situ conditions (96.5 % ± 4.5). These results demonstrate that the current consortium potential showed efficient and sustainable treatment of nitrite, nitrate in aquaculture system. Therefore, this work can be utilized for the treatment of nitrite and nitrate wastewater treatment plants.