Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 4/13/2009
Publication Date: 4/13/2009
Citation: Yossa, N., Patel, J.R., Millner, P.D., Lo, M. 2009. Biocontrol of Salmonella in organic soil using essential oils [ Abstract] .Annual GRID University of Maryland Meeting. Poster No. 7. Interpretive Summary:
Technical Abstract: Soil is one of the most important sources of preharvest contamination of produce with pathogens. Demand for natural pesticides such as essential oils for organic farming practices has increased. Antimicrobial activity of essential oils in vitro has been documented. The antimicrobial activity of essential oils was evaluated against Salmonella in soil. Three essential oils (Cinnamanaldehyde, ecotrol, eugenol) and vinegar at 0.5 and 2 percent were used in the study. Soil (10 g) in bags was inoculated individually with Salmonella cultures (S Thompson, S. Braenderup, S. Negev, S. Newport, S. Tennessee, S. Typhimurium) to have initial bacterial population ca. 6 log CFU/g soil. Soil samples without any oil served as a control. After 1, 7, and 28 days at room temperature (22 deg C), soil samples were plated on XLT4 agar plates. Following incubation at 37 deg C for up to 48 h, presumptive Salmonella colonies were counted. Vinegar and eugenol at 0.5 percent level significantly reduced Salmonella in soil irrespective of Salmonella ssp. Salmonella populations in soil reduced by up to 5 log CFU/ml after 28 days of incubation using vinegar or eugenol. The bactericidal effect of Cinnamanaldehyde was not evident either at 0.5 or 2 percent level. Overall, S. negev was the most sensitive strain to oils resulting in significant reduction compared to those with other Salmonella strains. Increase in oil concentration resulted in further reduction of Salmonella with all oils used in the study. This study shows potential use of oils to effectively reduce Salmonella populations in soil. The significant reduction of Salmonella could greatly reduce potential contamination to organic produce from soil.