Pitts, BetseyHamilton, Martin A.McFeters, Gordon A.Stewart, Philip S.Willse, Alan RayZelver, Nick2018-02-122018-02-121998-11Pitts, 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).0167-7012https://scholarworks.montana.edu/handle/1/14361Laboratory 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.Article