HR: 11:00h
AN: NB42B-03    [Abstracts]
TI: Bacterial and Fungal Responses to Algal Photosynthesis in Natural Wetland Periphyton
AU: * Francoeur, S N
EM: steve.francoeur@emich.edu
AF: Biology Department, Eastern Michigan University, Ypsilanti, MI 48197 United States
AU: Neely, R K
AF: Biology Department, Eastern Michigan University, Ypsilanti, MI 48197 United States
AU: Kuehn, K A
AF: Biology Department, Eastern Michigan University, Ypsilanti, MI 48197 United States
AB: Microbial communities associated with plant detritus are composed of a diverse assemblage of autotrophic and heterotrophic microbes, including algae, bacteria, and fungi. This study examined the potential for rapid, photosynthetically-mediated interactions among microbes inhabiting submerged litter of Typha angustifolia. We grew natural periphyton communities (containing algae, bacteria, and fungi) on submerged Typha litter in a local wetland, and then manipulated photosynthesis by controlling light (0 or 400 μmol m-2 s-1 PAR) while simultaneously quantifying rates of algal (14C-bicarbonate), bacterial (3H-leucine) and fungal (14C-acetate) productivity. Algal productivity was 50 to 100 fold greater at the high light intensity than at the low light intensity (p < 0.001). In addition, both bacterial (p < 0.001) and fungal (p = 0.005) productivities were significantly increased under high light intensities. The strong heterotrophic responses to light suggest that periphytic algal photosynthesis stimulated the productivities of litter-associated bacteria and fungi. Thus, microbial autotrophs may directly influence heterotrophic decay processes in wetland ecosystems.
DE: 4239 Limnology
DE: 4840 Microbiology
SC: North American Benthological Society [NB]
MN: 2005 Joint Assembly