Microbial Ecology

, Volume 52, Issue 2, pp 187–197

Microbial Exopolymers Link Predator and Prey in a Model Yeast Biofilm System


DOI: 10.1007/s00248-006-9063-7

Cite this article as:
Joubert, LM., Wolfaardt, G.M. & Botha, A. Microb Ecol (2006) 52: 187. doi:10.1007/s00248-006-9063-7


Protistan grazing on biofilms is potentially an important conduit enabling energy flow between microbial trophic levels. Contrary to the widely held assumption that protistan feeding primarily involves ingestion of biofilm cells, with negative consequences for the biofilm, this study demonstrated preferential grazing on the noncellular biofilm matrix by a ciliate, with selective ingestion of yeast and bacterial cells of planktonic origin over attached and biofilm-derived planktonic cells. Introducing a ciliate to two biofilm-forming Cryptococcus species, as well as two bacterial species in a model biofilm system, fluorescent probes were applied to determine ingestion of cellular and noncellular biofilm fractions. Fluoromicroscopy, as well as photometric quantification, confirmed that protistan grazing enhanced yeast biofilm metabolism, and an increase in biofilm biomass and viability. We propose that the extracellular polymeric matrix of biofilms may act as an interface regulating interaction between predator and prey, while serving as source of nutrients and energy for protists.


Yeast biofilms Predation Ciliate EPS 

Copyright information

© Springer Science+Business Media, Inc. 2006

Authors and Affiliations

  1. 1.Department of MicrobiologyUniversity of StellenboschStellenboschSouth Africa
  2. 2.Cell Sciences Imaging FacilityStanford UniversityStanfordUSA
  3. 3.Department of Chemistry and BiologyRyerson UniversityTorontoCanada

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