Using Bacteriophages in Recycled Water Exposure Assessment Studies

Bacteriophages MS-2 and PRD-1 were used as indicators of human viral behaviour in a series of turf-grass irrigation and washing machine experiments to provide information about the level of human exposure to potential residual enteric viruses in recycled water that can affect health. Results provided evidence to support a potential inadvertent exposure volume of 0.01 ml for recycled water used for machine clothes washing. Results for irrigation experiments showed that a one log reduction in bacteriophage numbers on turf-grass was not achieved under exposure to high solar conditions after 4 h. Experimentation showed that bacteriophages may be usefully employed in exposure assessment studies based on the ease of their enumeration and logistical and cost considerations. In terms of future studies, observed differences in individual bacteriophage characteristics provide a rationale for using multiple viral indicators. However, limitations on the utility of bacteriophage also need to be considered.     

Enhancement of lead uptake by alfalfa (Medicago sativa) using EDTA and a plant growth promoter

Phytoremediation is a novel cleanup technology for the removal of contaminants from polluted waters and soils. In phytoremediation, the plant uptake capability and the availability of the pollutant in the media are important. Here we show the results of a study on the combined effects of ethylenediaminetetraacetic acid (EDTA) and the phytohormone indole-3-acetic acid (IAA) on Pb uptake by Medicago sativa (alfalfa). Plants were grown in hydroponics media containing a nutrient solution amended with Pb at 0.2mM and different combinations of EDTA, and IAA. After 10d of treatment, the Pb content in plant tissues was quantified using an Inductively Coupled Plasma Optical Emission Spectrometer (ICP/OES). The results showed that the combination of 100 microM IAA/0.2 mM EDTA increased the Pb accumulation in leaves by about 2800% and by about 600%, as compared to Pb content in leaves of plants exposed to Pb alone and those cultivated with Pb/EDTA, respectively. These results indicate that non-metal hyperaccumulator plants could increase their hyperaccumulating potential without genetic manipulation.