Location: Produce Safety and Microbiology Research
Project Number: 2030-42000-050-25-I
Project Type: Interagency Reimbursable Agreement
Start Date: May 15, 2020
End Date: Sep 30, 2020
Investigate 1) the role of the water and soil microbiome on the microbiome of lettuce cultivated under commercial agricultural practices, and 2) the effect of plant genotype on the fresh-cut lettuce microbiome and colonization by E. coli O157:H7.
Lettuce of a commercial cultivar and of cultivars selected for their enhanced defense response will be planted in the field in Salinas, California. Under Objective 1, samples of irrigation water, air, soil, and lettuce will be collected starting at planting (including seeds), at mid-season when overhead irrigation changes to drip irrigation, and again at harvest. The samples will be sent to the FDA, Laurel, Maryland for microbiome analysis. Under Objective 2, lettuce of various genotypes will be harvested from the field and processed for fresh-cut lettuce production at ARS, Salinas. The cut lettuce will be transported to ARS, Albany, where it will be inoculated with E. coli O157:H7 and the effect of their genotype on EcO157 survival at 5C will be measured. Additionally, certain components of the plant defense response will be quantified and the microbiome characterized.