Total Coliform and Generic E. coli Levels, and Salmonella Presence in Eight Experimental Aquaponics and Hydroponics Systems: A Brief Report Highlighting Exploratory Data
Department of Environmental and Forest Biology, State University of New York, Environmental Science and Forestry, Syracuse, NY 13210, USA
Department of Biostatistics and Environmental Health, University of Rochester Medical Center, Rochester, NY 14642, USA
Department of Environmental Studies and Sciences, Ithaca College, Ithaca, NY 14850, USA
Author to whom correspondence should be addressed.
Horticulturae 2020, 6(3), 42; https://doi.org/10.3390/horticulturae6030042
Received: 1 July 2020 / Revised: 14 July 2020 / Accepted: 27 July 2020 / Published: 30 July 2020
(This article belongs to the Special Issue Aquaponics: Circular Sustainability for Food Security)
Although many studies have investigated foodborne pathogen prevalence in conventional produce production environments, relatively few have investigated prevalence in aquaponics and hydroponics systems. This study sought to address this knowledge gap by enumerating total coliform and generic E. coli levels, and testing for Salmonella presence in circulating water samples collected from five hydroponic systems and three aquaponic systems (No. of samples = 79). While total coliform levels ranged between 6.3 Most Probable Number (MPN)/100-mL and the upper limit of detection (2496 MPN/100-mL), only three samples had detectable levels of E. coli and no samples had detectable levels of Salmonella. Of the three E. coli positive samples, two samples had just one MPN of E. coli/100-mL while the third had 53.9 MPN of E. coli/100-mL. While the sample size reported here was small and site selection was not randomized, this study adds key data on the microbial quality of aquaponics and hydroponics systems to the literature. Moreover, these data suggest that contamination in these systems occurs at relatively low-levels, and that future studies are needed to more fully explore when and how microbial contamination of aquaponics and hydroponic systems is likely to occur.