Evaluation of Escherichia coli and coliforms in aquaponic water for produce irrigation. (October 2021)

• Record Type: Journal Article
• Authors: Dorick, Jennifer; Hayden, Michelle; Smith, Mollie; Blanchard, Caroline; Monu, Emefa; Wells, Daniel; Huang, Tung-Shi
• Is Part Of: Food microbiology. Volume 99(2021)
• Publication Date: 2021-10
• Subjects: Aquaponics -- E. coli -- Lettuce -- Tomato -- Cucumber -- Tilapia; Food Microbiology -- Periodicals; Aliments -- Microbiologie -- Périodiques; Food -- Microbiology; Periodicals; Food -- Microbiology -- Periodicals; Food contamination -- Periodicals; 664.001579
• DOI: 10.1016/j.fm.2021.103801
• Languages: English
• ISSNs: 0740-0020

Abstract

Abstract: The FDA Produce Safety Rule states that water used for irrigation purposes, likely to come into contact with the edible portion of fruit and vegetables, must not exceed a defined limit of Escherichia coli populations. Although aquaponics has not been included in this guideline, it is worth investigating to establish a baseline for facilities to reference in produce production. Two microbial assays were performed, one a decoupled media-based aquaponics system over one year and another on a decoupled nutrient film technique (NFT) aquaponics system over 16 days. Water was sampled from each system over time to analyze changes of E. coli and coliforms. The geometric mean (GM) and statistical threshold variable (STV) were calculated based on E. coli populations from the irrigation source in each system. From the first experiment, it was determined, based on the FDA Produce Safety Rule, that E. coli must be monitored more closely from June to January as they were above the advised limit. The second experiment determined that E. coli and coliforms in the water significantly decreased over 16 days. Water should be held for 8 d and up to 16 d to reduce the likelihood of foodborne pathogens to contaminate produce. Highlights: Foodborne pathogens could transfer from aquaculture effluent to produce in aquaponics. Surface water used in aquaponics should be monitored for pathogen transportation. E. coli was found in an aquaponic system over one-year and increased Jun to Jan. Generic E. coli significantly decreased in a decoupled NFT system over 16 days. Aquaponic NFT water should be held between 8 and 16 days following FSMA.