(Montana State University - Bozeman, College of Engineering, 2006) Rani, Suriani Abdul; Chairperson, Graduate Committee: Philip S. Stewart
Biofilms harbor both active and inactive cells and it is a challenge to characterize the spatial and population heterogeneity of specific activities within a biofilm. Spatial patterns of DNA replication and protein synthetic activity were imaged by techniques developed using staphylococcal systems. The first technique measures DNA synthetic activity by pulse-labeling with the thymidine analog 5-bromo-2-deoxyuridine (BrdU) followed by immunofluorescent detection of brominated DNA. The second technique makes use of an inducible green fluorescent protein construct that can be used to detect the capacity for de novo protein synthesis. These techniques were applied to biofilms grown in three different reactor systems. In all cases, measurements revealed that even in simple single-species biofilms, complex spatial distributions of anabolic activity occur. In a colony biofilm system, two distinct regions of DNA synthetic activity were observed, one close to the nutrient interface and another adjacent to the air interface. A similar pattern was measured by GFP induction.
