Article Figures & Data
Figures
- FIG. 1.
Seasonal changes in oocyst retention by biofilms using a standard laboratory water temperature (20 to 25°C). The cumulative percentage of oocysts associated with the biofilm over time for summer, fall, winter, and spring biofilm cultures was determined. Error bars show the percent standard error (n = 2) and are smaller than the symbols where not visible. The black line on the time axis indicates the period of oocyst dosing (0 to 72 h).
- FIG. 2.
Testing the effect of experimental water temperature on oocyst retention by biofilm. The cumulative percentage of oocysts associated with the biofilm over time with winter culture biofilm grown at 5°C (ambient biofilm collection temperature) and at 20 to 25°C (normal laboratory experimental temperature) was determined. Error bars indicate the percent standard error (n = 2) and are smaller than the symbols where not visible. The black line on the time axis indicates the period of oocyst dosing (0 to 72 h).
- FIG. 3.
Cumulative percentage of oocysts associated with the biofilm at the end of oocyst dosing (day 3) and the end of the experiment (day 8). The error bars indicate the percent standard error (n = 2).
- FIG. 4.
Effect of changing flow media on oocyst retention by biofilm. The cumulative percentage of oocysts associated with the biofilm over time with fall biofilm grown with fall water, fall biofilm grown with spring water, spring biofilm grown with fall water, and spring biofilm grown with spring water was determined. The error bars show the percent standard error (n = 2) and are smaller than the symbols where not visible. The black line on the time axis indicates the period of oocyst dosing (0 to 72 h).
- FIG. 5.
Correlation of several water quality measures and oocyst retention by biofilms. The percentages of oocysts attached to biofilms at day 3 and day 8 versus water temperature at the time of biofilm collection (A), pH (B), conductivity (C), and DOC concentration (D) were determined. Spearman correlation coefficients and P values for each parameter are indicated on each panel.
Tables
- TABLE 1.
Oocyst retention and biofilm thicknessa
Season % Oocysts ± SE Avg biofilm thickness (μm) In biofilm at end of dosing (day 3) In biofilm at end of expt (day 8) Accounted for in flow system Summer 2008 64 ± 3.2 28 ± 0.05 107 ± 0.93 42 ± 3.5 Fall 2008 46 ± 4.5 24 ± 0.67 104 ± 0 28 ± 5.1 Winter 2009 72 ± 0.89 47 ± 3.2 97.5 ± 0.51 34 ± 10 Spring 2009 78 ± 1.4 65 ± 1.7 94.5 ± 0.53 25 ± 11 Winter 2009 (20°C) 77 ± 0.62 54 ± 1.4 94.5 ± 1.6 30 ± 12 Winter 2009 (5°C) 76 ± 0.31 53 ± 2.7 103.5 ± 0.48 33 ± 11 ↵ a The table presents a summary of the percentage of oocysts attached to each biofilm at the end of the dosing period (day 3) and end of the experiment (day 8), the total percent of oocysts accounted for in the flow system, and the average biofilm thickness for each set of seasonal biofilms. All errors are percent standard error (n = 2, except biofilm thickness, where n = 8).
