HR: 14:15h
AN: B23A-04 INVITED     [Abstracts]
TI: Factors Influencing Biofilm Formation in Streams: Bacterial Colonization, Detachment and Transport
AU: * Leff, L
EM: lleff@kent.edu
AF: Kent State University, Dept. of Biological Sciences, Kent, OH 44242
AB: Surfaces in aquatic systems develop biofilms containing microorganisms embedded in complex extracellular matrices. Properties of the surface, water, and colonizing organisms impact biofilm formation. Biofilm features, physical disturbance, and interactions between macro- and microscopic organisms, in turn, influence detachment. In spite of the importance of biofilms, much remains unknown about factors controlling biofilms in streams and other natural environments. Experiments were conducted in the laboratory and field to examine factors influencing surface colonization, and subsequent biofilm formation, and detachment. Microscopy methods, fluorescent in situ hybridization and confocal laser microscopy, were used to examine responses, including abundance of different taxa and biofilm depth. From these experiments, we determined that different taxa differ in their colonization ability based on properties like extracellular polysaccharide production and surface features, like hydrophobicity and that water chemistry, such as magnesium concentration, plays an important role. Moreover, detachment varies among taxa and with environmental conditions and may be enhanced by activities of macrofauna. Variation in detachment, in turn, influences bacterial transport and subsequent re-attachment. Overall, examination of attachment, detachment, and interactions in biofilms allows us to begin to understand how environmental conditions may impact the function of these communities in aquatic systems.
DE: 0400 Biogeosciences
SC: Biogeosciences [B]
MN: 2005 Joint Assembly