title: Influence of Algal Photosynthesis on Biofilm Bacterial Production and Associated Glucosidase and Xylosidase Activities.
abstract: Natural photosynthetic biofilms were incubated under light (100 mmol m-2 s-1) and dark conditions to elucidate the impact of photosynthesis on bacterial production, abundance, biovolume, biomass, and enzyme activities over 24 h. Use of organic carbon-free media limited carbon sources to algal photosynthesis and possibly the polysaccharides of the biofilm matrix. Bacterial production of biofilm communities was significantly higher in light incubations (p <0.001). The greatest differences in production rates between light and dark incubations occurred between 8 and 24 h. Biomass-specific a- and b-glucosidase and b-xylosidase activities were stimulated by photosynthesis, with significantly greater activities occurring at hours 16 and 24 in the light treatment (p <0.01). The results indicate that algal photosynthesis can have a significant impact on bacterial productivity, biomass, biovolume, and enzyme production over longer time periods at low photon flux densities (?100 mmol m-2 s-1).
authors.affiliation: Department of Biological Sciences, The University of Alabama, Tuscaloosa, AL 35487-0206, USA.
authors.forename: E.M.
authors.initials: EM
authors.lastname: Espeland
authors.forename: S.N.
authors.initials: SN
authors.lastname: Francoeur
authors.forename: R.G.
authors.initials: RG
authors.lastname: Wetzel