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<p>The objective of this project is to ensure food safety from the toxin algae and toxin contamination in fresh produce. For this, three specific aims are proposed:</p><p>1) determine whether toxins accumulate in plants when the irrigation water contains toxin and harmful cyanobacteria;</p><p> 2) develop methods to treat the toxins and harmful cyanobacteria in irrigation water; and</p><p> 3) develop methods to decompose toxins and harmful cyanobacteria internalized in fresh produce.</p><p> With the outcome of this study, we can answer an emerging food safety concern which has never been fully studied. The results from this project can propose a human safety guideline for fresh produce grown with irrigation water containing MCs. The developed methods will provide a tool for treating the toxin-contaminated irrigation water and food in an environmental friendly way with health hazards.</p>
<p>Procedure Specific Aim #1: Toxin accumulation and fate in plants when the irrigation water contains toxin and harmful cyanobacteria To quantify potential risk to human health from contaminated fresh produce, the MC- and Microcystis aeruginosa-containing water will be used to treat fresh produce during cultivation period at different environmental conditions, which is the most common toxin producer in western Lake Erie and inland reservoirs, and worldwide. After harvesting the fresh produce, the concentrations of M. aeruginosa in the crops will be determined by quantitative PCR by targeting PC-IGS and mcy genes. The amount of microcystins will be measured using Liquid Chromatography/Mass Spectrometry (LC/MS) in addition to enzyme-linked immunosorbent assay (ELISA). Specific </p><p>Aim #2: Develop methods to treat the toxins and harmful cyanobacteria in irrigation water To decompose cyanobacteria or MCs in irrigation water, a best method will be developed to apply TiO2 (designing a recyclable device that holds the TiO2-containing floater) on the surface of irrigation water that maximizes natural UV irradiation to decompose the toxins and algal cells. Several microcosms will be built to contain irrigation water (e.g. irrigation ponds water). The water will be prepared having significant level of cyanobacterial blooms. Under multiple conditions of treatment, water will be tested for microcystin levels in each settings using LC/MS-MS and ELISA methods. The water samples will be also collected and tested with qPCR mentioned above for investing the bloom dynamics under diverse conditions. </p><p>Specific Aim #3: Develop methods to decompose toxins and harmful cyanobacteria internalized in fresh produce.To decompose cyanobacteria or MCs on and in fresh produce, an optimal treatment method of TiO2 with UV irradiation will be developed. Their synergic effect will be measured. After harvest the fresh produce (e.g. lettuce) grown with M. aeruginosa-contaminated water, TiO2 suspensions will be applied to the contaminated fresh produce and UV will be irradiated.</p><p> Three groups will be tested to compare its effectiveness:</p><p> 1) no treatment (control),</p><p> 2) UV treatment, and </p><p>3) UV+TiO2 treatment. Under multiple conditions of treatment, fresh produce will be tested for microcystin levels in condition using LC/MS-MS and ELISA methods. Each group will be tested in 10 replicates.</p>