2018 ASHS Annual Conference
Evaluating the Presence of Foodborne Pathogens in Aquaponics Incomparison to Hydroponics. Wang, Y.J., T. Yang, a.J. Deering, and H.J. Kim
Wang, Y.J., T. Yang, A.J. Deering, and H.J. Kim
Aquaponics, a growing trend in food production, integrates aquaculture and hydroponics into one system where plants get nutrition from aquaculture wastewater. Bacteria function as biofilter to convert ammonia into nitrite and nitrate, plants absorb ammonia and nitrate, and then water is returned to the fish tanks. Aquaponics offer a promising solution for sustainable food production by reducing the usage of water and chemical fertilizers. However, due to the reuse and recycling of waste and waste-derived materials, it is important to appropriately assess and manage potential risks associated with food safety in aquaponics systems. Therefore, the aim of this study was to determine the presence of foodborne pathogens in aquaponics systems. To assess product safety, we collected irrigation water and plant tissues from two different food production systems: aquaponics and hydroponics. Common foodborne illness pathogens (Escherichia coli O157:H7) of vegetables were analyzed. We collected lettuces leaves and roots after 30-day production period. Weighing 25 g of plant tissue into 225 ml peptone water buffer, blend or stomach briefly as necessary. A series of inoculum dilutions were prepared and spread onto selective agar plates. Colonies were counted after incubated at 37 ºC for 20 hours. We found there were no differences in the number of colonies in the leaves of lettuce grown in aquaponics and hydroponics; however, the number of colonies was 2.8-fold higher in the roots of lettuce grown in hydroponics than aquaponics. This may be due to the fact that the concentrations of nitrogen and phosphorous in hydroponics systems are nearly 4-fold higher, respectively, than aquaponics, providing more resources for bacterial growth in hydroponics. We are investigating a culture-based survey of E.coli O157:H7, Salmonella spp., and Listeria monocytogenes in basils and tomatoes in addition to lettuce. Key outcomes are expected to identify the food safety issues in aquaponics systems and to enable future research projects to be targeted for commercial production of concern to fill any knowledge gaps.