| Biofilms containing filamentous bacteria occur on paper machine surfaces and interfere with production efficiency and product quality. Two paper mills and supply rivers were monitored using traditional and cultivation-independent, molecular techniques to examine seasonal changes in the density of filamentous bacteria and community composition. The contribution of freshwater microorganisms to paper machine biofilms was also examined.; Densities of bacterial filaments exhibited seasonal trends in both study rivers. Bacterial densities in the study rivers exhibited positive correlation with densities in paper machine biofilms, suggesting a potential contribution of freshwater microorganisms to problematic paper machine biofilms.; Molecular analyses demonstrated that bacteria present in the supply rivers, including filamentous bacteria, exhibit high sequence similarity to those found in paper machine biofilms. In the past, Sphaerotilus natans was reported to be the predominant filamentous bacterium contributing to these problematic biofilms. This work uncovered wide distribution of green nonsulfur bacteria in river and paper machine biofilms. A better understanding of the key organisms contributing to these problematic deposits will lead to the development of more effective monitoring programs and control measures, which could ultimately reduce the use of biocides in industrial water systems. |
