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ARS Home » Northeast Area » Beltsville, Maryland (BARC) » Beltsville Agricultural Research Center » Environmental Microbial & Food Safety Laboratory » Research » Publications at this Location » Publication #328345

Research Project: Design and Implementation of Monitoring and Modeling Methods to Evaluate Microbial Quality of Surface Water Sources Used for Irrigation

Location: Environmental Microbial & Food Safety Laboratory

Title: Escherichia coli survival in the presence of Chlorella vulgaris in a nutrient supplemented freshwater medium

item Kierzewski, Rachel
item KIEFER, LYNDA - Orise Fellow
item KANGAS, PATRICK - University Of Maryland
item Mulbry, Walter
item Pachepsky, Yakov
item Shelton, Daniel

Submitted to: BARC Poster Day
Publication Type: Abstract Only
Publication Acceptance Date: 4/13/2016
Publication Date: 4/27/2016
Citation: Kierzewski, R.A., Kiefer, L., Kangas, P., Mulbry Iii, W.W., Pachepsky, Y.A., Shelton, D.R. 2016. Escherichia coli survival in the presence of Chlorella vulgaris in a nutrient supplemented freshwater medium. BARC Poster Day. 27th Annual Beltsville Poster Day on April 27, 2016.

Interpretive Summary:

Technical Abstract: Fecal contamination of agricultural irrigation pond water is an on-going concern. Others have reported that fecal bacteria survival can be mediated by algae in natural ecosystems. The effect of bovine manure nutrient supplementation on the survival of E. coli in the presence of the single-celled alga Chlorella vulgaris was investigated. Four 20 gallon microcosms, including an uninoculated control, were prepared with E. coli or algae alone or E. coli plus algae. The growth medium consisted of synthetic pond water and sterilized manure slurry. Light and temperature were controlled to mimic pond water conditions during a Maryland summer. Water samples were collected and analyzed twice a week for changes in E. coli, total aerobic heterotophic bacteria (THB) and C. vulgaris concentrations. Physico-chemical properties were also monitored. After four weeks, results indicated that THB and E. coli concentrations did not significantly differ in the presence or absence of C. vulgaris. However, results were confounded by analytical difficulties that prevented accurate measurement of Chlorella survival. Future work will evaluate the effects of low nutrients and wild algae on E. coli growth and survival.