River biofilms

Lawrence JR, Swerhone GD, Topp E, Korber DR, Neu TR, Wassenaar LI (2007) Structural and functional responses of river biofilm communities to the nonsteroidal anti-inflammatory diclofenac. Environ Toxicol Chem 26 573-582... 

Yergeau E, Lawrence JR, Waiser MJ et al (2010) Metatranscriptomic analysis of the response of river biofilms to pharmaceutical products, using anonymous DNA microarrays. Appl Environ Microbiol 76(16) 5432-5439... 

Monosaccharides 1.8 h residence time Model river biofilm on High (59) Volk etal. (1997)... 

High-molecular- 30 min residence time, Natural river biofilm High (39) Fischer et al. (2002)... 

Fluvial biofilms (also known as phytobenthos or periphyton) are attached communities consisting of bacteria, algae and fungi embedded within a polysaccharide matrix [20]. In rivers, these communities are the first to interact with... 

Cu Acute toxicity on biofilms EC50 ( C) 20-50 (spring) 100-350 (summer) EC50 (Y) 230 (low P) 718 (highP) EC50 (Fo) 56-92 (low P) 196-206 (high P) Field samples Ter river" Fluvial microcosms Field samples"... 

Boeije GM, Schowanek DR, Vanrilleghem A (2000) Incorporation of biofilm activity in river biodegradation modeling a case study for linear alkylbenzene sulphonate (LAS). Wat Res 34 1479... 

Barranguet C, Plans M, Van der Grinten E, Sinke JJ, Admiraal W (2002) Development of photosynthetic biofilms affected by dissolved and sorbed copper in a eutrophic river. Environ Toxicol Chem 21 1955... 

Structure and function need to be jointly considered in the assessment of effects of stressors on river systems. It has been shown that the two sets of parameters offer complementary information since they cover different time scales and responses. This being shown in the case of biofilms is not a unique characteristic of them, but it might be applied to all other biological communities (e.g. macroinvertebrates, fish). These differ from the biofilm in its higher size and life span, and therefore in their integrative capacity to reflect effects in one part of the ecosystem. Higher traffic levels in addition to biofilms should be considered to study the whole ecosystem. In all of these biological compartments, the combined use of descriptors may amplify our ability to predict the effect of stressors on river basins. 

Bjerre, H.L., T. Hvitved-Jacobsen, S. Schlegel, and B. Teichgraber (1998), Biological activity of biofilm and sediment in the Emscher river, Germany, Water Sci. Tech., 37(1), 9—16. 

Investigations have been performed to exemplify the DO surface removal rates from biofilms grown on different types of wastewater (Bjerre et al., 1998b). Such investigations may indicate if Equation (5.3) can be considered an appropriate description of the aerobic activity. The wastewater for these studies originates from an open sewer system, the Emscher river, Germany. The results of the experiments are outlined in Table 5.2, and further details are shown in Figures 5.6 and 5.7. 

Several examples support the view that QS in fact plays a role in natural biofilms. By the use of AHL biosensors it has been shown that AHL molecules are present in natural biofilms growing on submerged rocks in a river as well as in biofilms formed on urethal catheters [39,81]. Direct chemical evidence for the presence of high concentrations of AHL signal molecules in P. aeruginosa biofilms has been presented by Charlton et al. [48], who reported that the concentration of 30,C12-HSL is approximately 45-fold higher in biofilms relative to suspended cultures. 

Farag, A.M., Woodward, D.F., Goldstein, J.N. et al. (1998) Concentrations of metals associated with mining waste in sediments, biofilm, benthic macroinvertebrates, and fish from the Coeur d Alene River Basin, Idaho. Archives of Environmental Contamination and Toxicology, 34(2), 119-27. 

Because of the high area of solid surfaces covered with biofilms, these biofilms dominate the heterotrophic metabolism in many aquatic ecosystems. In streams, rivers, and shallow lakes, bacterial activity in epilithic and epiphytic biofilms may be several times higher on an areal basis than the activity of free living bacteria. By the differential use of specific DOM fractions, biofilm bacteria influence the biogeochemical composition of DOM in these ecosystems. Biofilms thus can control biogeochemical fluxes of DOM and are important sinks of organic matter. 

Neu, T. R., and J. R. Lawrence. 1997. Development and structure of microbial biofilms in river water studied by confocal laser scanning microscopy. FEMS Microbiology Ecology 24 11-2 5. 

Sinsabaugh, R. L., S. W. Golladay, and A. E. Linkins. 1991. Comparison of epilithic and epixylic biofilm development in a boreal river. Freshwater Biology 25 179-187. 

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