Related Experiment Video
Updated: Jan 15, 2026

Hydroponics: A Versatile System to Study Nutrient Allocation and Plant Responses to Nutrient Availability and Exposure to Toxic Elements
Published on: July 13, 2016
Effect of pH, Nutrient Composition, and UV-C Light Treatment on Listeria monocytogenes in Hydroponic Nutrient
Janny Mendoza1, Ivannova Lituma1, Kathryn Fontenot2
1School of Nutrition and Food Sciences, Louisiana State University AgCenter, 261 Knapp Hall, Baton Rouge, LA 70803, United States.
Abstract:
Hydroponic nutrient solutions may create favorable conditions for the growth of environmental pathogens such as L. monocytogenes. This study evaluated the growth and survival of L. monocytogenes in distilled water and tomato, lettuce, and strawberry nutrient solutions at pH 5, 6, and 7 over 72 h, and assessed the effectiveness of UV-C treatment (1.32 mW/cm2) for microbial reduction. Distilled water at pH 5 supported limited survival, with counts decreasing from 2.96 to 2.20 log CFU/mL (p ≤ 0.05). In tomato solutions, L. monocytogenes levels showed minimal change, while lettuce and strawberry solutions supported significant growth, particularly at pH 6, indicating that both pH and nutrient composition influence pathogen behavior. UV-C treatment significantly (p ≤ 0.05) reduced L. monocytogenes across all nutrient solutions with greater reduction observed at longer exposure times. In lettuce solutions, 5, 10, and 15 s exposures decreased populations from 5.70 log CFU/mL to 4.61, 2.26, and 1.38 log CFU/mL, respectively, with similar reductions in tomato (to 4.49, 2.14, and 1.04 log CFU/mL) and strawberry solutions (to 4.50, 2.19, and 1.75 log CFU/mL). These results demonstrate that hydroponic solutions can facilitate L. monocytogenes survival depending on pH and nutrient content. While UV-C offers a promising intervention strategy, further work is needed to optimize decontamination approaches for hydroponic food production systems.
Related Concept Videos
Physical Methods for Controlling Microbial Growth: Radiation and Filtration
Factors Influencing Microbial Growth: pH
Methods for Controlling Microbial Growth
Physical Methods for Controlling Microbial Growth: Temperature

