Color measurement as a means of quantifying surface biofouling
Hamilton, Martin A.
McFeters, Gordon A.
Stewart, Philip S.
Willse, Alan Ray
MetadataShow full item record
Laboratory reactors fitted with removable ceramic porcelain growth surfaces were inoculated with a consortium of biofilm forming environmental isolates. A Minolta colorimeter CR-200 (Minolta Camera Co., Ltd, Ramsey, NJ) was used in conjunction with a specially designed adapter to evaluate the reflective color of the porcelain disks as biofilm accumulated on them. Areal viable cell counts were monitored over a period of eleven days in two separate experiments and direct color measurements of the untreated, microbially fouled test surfaces were collected. This colorimetric assay was both non-destructive and immediate. A strong linear relationship between log cell density and log color change was observed. The Pearson product moment correlation coefficient for all 45 observations combined was r=0.95. Separate regression lines for each experiment were not significantly different (P=0.19). When adjusted for time, the (partial) correlation coefficient between log cell density and log color change was r=0.87, which suggests that the relationship between the two measures can not be explained by their mutual dependence on time. Reflective color measurement provided a rapid, non-destructive and quantitative measure of biofilm accumulation.
Pitts, B., M.A. Hamilton, G.A. McFeters, P.S. Stewart, A. Willse, and N. Zelver, "Color Measurement as a Means of Quantifying Surface Biofouling," Journal of Microbiological Methods, 34:143-149 (1998).