Competition in biofilms

T. C. Zhang, Y. C. Fu, P. L. Bishop

Research output: Contribution to journalConference articlepeer-review

57 Scopus citations


Competitions in biofilms for substrate and space have been studied by using a microelectrode technique and a microslicing technique. Three different kinds of biofilms, cultured by laboratory-scale rotating drum biofilm reactors (RDBR) with synthetic wastewater, have been used as test materials. Oxygen, ammonium-nitrogen, nitrate-nitrogen, and pH concentration profiles in the biofilms were measured using microelectrodes. Experimental results showed that: 1) an increase of organic loading rate would result in a decrease of DO concentration in the biofilm. However, after the organic loading rate exceeded a certain value, the oxygen profiles within the biofilm did not change any more, 2) Heterotrophs competed for oxygen with nitrifiers, which resulted in the inhibition of nitrification because of the shortage of oxygen. Glucose itself, however, did not inhibit the nitrification processes; and 3) The competition for substrate in biofilms resulted in a stratified biofilm structure. Experiments showed that competition in biofilms resulted in non-uniform spatial distributions of bacterial populations and metabolically active bacteria. The spatial distributions of biotic and abiotic components in turn affected the substrate transfer and substrate competition within the biofilm. Traditional biofilm modelling will fail in many cases if they are based on substrate removal kinetics and uniform distributions of biofilm properties.

Original languageEnglish (US)
Pages (from-to)263-270
Number of pages8
JournalWater Science and Technology
Issue number10-11
StatePublished - 1994
Externally publishedYes
EventProceedings of the IAWQ 2nd International Specialized Conference on Biofilm Reactors - Paris, Fr
Duration: Sep 29 1993Oct 1 1993


  • Biofilm
  • Competition
  • DO concentration
  • Heterotrophs
  • Microelectrode
  • Nitrifiers
  • Space
  • Substrate
  • Substrate profile

ASJC Scopus subject areas

  • Environmental Engineering
  • Water Science and Technology


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