Quantification and characterization of nitrifying bacteria isolated from an aquaponic system

Nitrifying bacteria are essential in aquaponic systems because they transform nitrogenous waste into useful plant nutrients, preventing ammonium toxicity in fish. This study aimed to quantify and characterize cultivable nitrifying bacteria in an aquaponic system over time, using two replicated systems with watercress (Nasturtium officinale), and the fishes Nile tilapia (Oreochromis niloticus), red tilapia (Oreochromis sp.), and white pacu (Piaractus orinoquensis). Samples were collected at three moments (0, 3, and 6 months) from the fish tank, hydrocyclone, and biofilter. The highest bacterial abundance was detected in the fish tanks, likely due to higher oxygen levels and nutrient availability, with a consistent increase over time. Correlation analysis indicated that certain nutrients, such as potassium, phosphate, manganese, and nitrate, could favor the proliferation of nitrifying bacteria. Nine bacterial morphotypes were isolated and phenotypically characterized, with most displaying Gram-positive staining and negative urea hydrolysis. This study provides insight into the spatiotemporal dynamics of nitrifying bacteria in aquaponic systems, highlighting their role in nutrient cycling. The high bacterial abundance observed underscores the system’s potential for efficient nutrient reuse. Molecular techniques such as 16S rRNA gene sequencing and metagenomics are recommended to confirm bacterial identity and better understand community structure. These findings reinforce the ecological importance of nitrifying bacteria in system performance and advancing sustainable agricultural practices

• Autores: Naranjo Robayo, Natalia; Castro Gonzalez, Maribeb; Gómez Ramírez, Edwin
• Tipo de recurso: Article of investigation
• Fecha de publicación: 2025
• Institución: Universidad de Ciencias Aplicadas y Ambientales U.D.C.A
• Repositorio: Repositorio Institucional UDCA
• Idioma: eng
• OAI Identifier: oai:repository.udca.edu.co:11158/6520
• Acceso en línea: https://repository.udca.edu.co/handle/11158/6520; https://doi.org/10.31910/rudca.v28.n1.2025.2653; https://repository.udca.edu.co/
• Palabra clave: 630 - Agricultura y tecnologías relacionadas::639 - Caza, pesca, conservación, tecnologías relacionadas; Bacterias nitrificantes; Cultivos hidropónicos; Hydroponics; Nitrification; Pisciculture; Recirculating nutrient systems; Sustainable agriculture; Piscicultura; Nitrificación; Agricultura sostenible
• Rights: openAccess
• License: https://creativecommons.org/licenses/by-nc-sa/4.0/legalcode.es