Distribution and activity of ammonia oxidizing bacteria in a large full-scale trickling filter.

The biofilm in a full-scale nitrifying trickling filter (NTF) treating municipal wastewater has been investigated with microbiological methods using fluorescence in situ hybridization (FISH) with 16S rRNA oligonucleotide probes in combination with confocal laser scanning microscopy (CLSM) and mathematical modeling using a dynamic multi-species biofilm reactor model. Ammonia oxidizing bacteria (AOB) were found to belong to the genus Nitrosomonas at different depths in the NTF at every sampling occasion, corresponding to different long-term operational conditions for the NTF. Both the measurements and the corresponding simulated predictions showed the same general trend of a decrease with filter depth of the amount of biofilm, the proportion of AOB to all bacteria and the total amount of AOB. The latter decreased by several times from top to bottom of the NTF. Measurements and simulations of potential ammonium oxidizing activity in the biofilm also showed a decreasing activity with depth in the NTF, which generally was operating at close to complete nitrification. However, no difference was observed when the activity was normalized to the amount of biofilm, despite decreasing proportions of AOB to all bacteria with depth in the NTF. This could be explained by diffusion limitations in the biofilm from the upper parts of the NTF according to the biofilm reactor model. The relatively good agreement between the simulations and the measurements shows that the kind of biofilm reactor model used can qualitatively describe an averaged behavior and averaged composition of the biofilm in the reactor.

[1]  P. García-Encina,et al.  Influence of pH over nitrifying biofilm activity in submerged biofilters , 1997 .

[2]  Y. Watanabe,et al.  Dynamic changes in spatial microbial distribution in mixed-population biofilms: experimental results and model simulation , 1995 .

[3]  K. Schleifer,et al.  Combined Molecular and Conventional Analyses of Nitrifying Bacterium Diversity in Activated Sludge: Nitrosococcus mobilis and Nitrospira-Like Bacteria as Dominant Populations , 1998, Applied and Environmental Microbiology.

[4]  W. Gujer,et al.  A Mathematical Model for Rotating Biological Contactors , 1990 .

[5]  D A Stahl,et al.  Fluorescent-oligonucleotide probing of whole cells for determinative, phylogenetic, and environmental studies in microbiology , 1990, Journal of bacteriology.

[6]  R. Amann,et al.  In situ analysis of nitrifying bacteria in sewage treatment plants , 1996 .

[7]  D. Hempel,et al.  Growth and decay in an auto-/heterotrophic biofilm , 1997 .

[8]  W Gujer,et al.  A multispecies biofilm model , 1986, Biotechnology and bioengineering.

[9]  J. Tiedje,et al.  Effects of pH and Oxygen and Ammonium Concentrations on the Community Structure of Nitrifying Bacteria from Wastewater , 1998, Applied and Environmental Microbiology.

[10]  K. Schleifer,et al.  Probing activated sludge with oligonucleotides specific for proteobacteria: inadequacy of culture-dependent methods for describing microbial community structure , 1993, Applied and environmental microbiology.

[11]  K. Schleifer,et al.  Phylogenetic Oligodeoxynucleotide Probes for the Major Subclasses of Proteobacteria: Problems and Solutions , 1992 .

[12]  K. Schleifer,et al.  Structure and function of a nitrifying biofilm as determined by in situ hybridization and the use of microelectrodes , 1996, Applied and environmental microbiology.

[13]  K. Schleifer,et al.  The domain-specific probe EUB338 is insufficient for the detection of all Bacteria: development and evaluation of a more comprehensive probe set. , 1999, Systematic and applied microbiology.

[14]  R Amann,et al.  Monitoring a widespread bacterial group: in situ detection of planctomycetes with 16S rRNA-targeted probes. , 1998, Microbiology.

[15]  J. Keller,et al.  Microbiology of a Nitrite-Oxidizing Bioreactor , 1998, Applied and Environmental Microbiology.

[16]  Dimitrios V. Vayenas,et al.  Development of a dynamic model describing nitritification and nitratification in trickling filters , 1997 .

[17]  M. Wagner,et al.  Phylogenetic probes for analyzing abundance and spatial organization of nitrifying bacteria , 1996, Applied and environmental microbiology.

[18]  T. Wik.  Adsorption and denitrification in nitrifying trickling filters , 1999 .

[19]  E. Arvin,et al.  Growth of an aerobic and an anoxic toluene-degrading biofilm - a comparative study , 1995 .

[20]  Manfred Ehrhardt,et al.  Methods of seawater analysis , 1999 .

[21]  O. Wanner.  New experimental findings and biofilm modelling concepts , 1995 .

[22]  I. Nes,et al.  A qualitative evaluation of the published oligonucleotides specific for the 16S rRNA gene sequences of the ammonia-oxidizing bacteria. , 1998, Systematic and applied microbiology.

[23]  W. Gujer,et al.  Significance of Spatial Distribution of Microbial Species in Mixed Culture Biofilms , 1991 .

[24]  M. Wagner,et al.  Novel Nitrospira-like bacteria as dominant nitrite-oxidizers in biofilms from wastewater treatment plants: diversity and in situ physiology , 2000 .

[25]  S. Okabe,et al.  In Situ Analysis of Nitrifying Biofilms as Determined by In Situ Hybridization and the Use of Microelectrodes , 1999, Applied and Environmental Microbiology.

[26]  K. Schleifer,et al.  Phylogenetic identification and in situ detection of individual microbial cells without cultivation. , 1995, Microbiological reviews.

[27]  R. Amann,et al.  Identification and Activities In Situ of Nitrosospiraand Nitrospira spp. as Dominant Populations in a Nitrifying Fluidized Bed Reactor , 1998, Applied and Environmental Microbiology.

[28]  Robert L. Street,et al.  Numerical Simulation of Mixed-Culture Biofilm , 1984 .

[29]  D. Hempel,et al.  Substrate utilization and mass transfer in an autotrophic biofilm system: Experimental results and numerical simulation. , 1997, Biotechnology and bioengineering.

[30]  K. Schleifer,et al.  In situ Identification of Ammonia-oxidizing Bacteria , 1995 .

[31]  Willi Gujer,et al.  Competition in Biofilms , 1985 .

[32]  M. Wagner,et al.  Phylogeny of All Recognized Species of Ammonia Oxidizers Based on Comparative 16S rRNA and amoA Sequence Analysis: Implications for Molecular Diversity Surveys , 2000, Applied and Environmental Microbiology.

[33]  T. Wik.  Strategies to improve the efficiency of tertiary nitrifying trickling filters , 2000 .

[34]  Willi Gujer,et al.  Nitrification in tertiary trickling filters followed by deep-bed filters , 1986 .

[35]  Gabriele Rath,et al.  Phylogenetic Diversity within the Genus Nitrosomonas , 1996 .