Eco-physiology of autotrophic nitrifying biofilms

Microautoradiography combined with fluorescent in situ hybridization (MAR-FISH), a powerful tool for linking physiology with identification of individual cells, was applied to investigate microbial interactions between nitrifying bacteria and coexisting heterotrophic bacteria in an autotrophic nitrifying biofilm community fed with only ammonia as the sole energy source and bicarbonate as the sole carbon source. First, nitrifying bacteria were radiolabeled by culturing the biofilm samples with [ 14 C]bicarbonate for 6 h, and then the transfer of radioactivity from nitrifying bacteria to heterotrophic bacteria was monitored by using MAR-FISH. MAR-FISH revealed that the heterotrophic bacterial community was composed of bacteria that were phylogenetically and metabolically diverse. We could obtain direct evidence that organic matter derived from nitrifiers was subsequently utilized by mainly filamentous bacteria belonging to the Chloroflexi (green non-sulfur bacteria) group or CFB group in the biofilm, which was clearly visualized by MAR-FISH at single cell resolution for the first time. On the other hand, the members of the α- and γ- Proteobacteria were specialized to utilize low-molecular-weight organic matter. This community represents functionally integrated units that assure maximum access to and utilization of metabolites of nitrifiers.

[1]  S. Okabe,et al.  Analysis of size distribution and areal cell density of ammonia‐oxidizing bacterial microcolonies in relation to substrate microprofiles in biofilms , 2004, Biotechnology and bioengineering.

[2]  Y. Watanabe,et al.  Eco-physiological interaction between nitrifying bacteria and heterotrophic bacteria in autotrophic nitrifying biofilms as determined by MAR-FISH , 2003 .

[3]  J. Nielsen,et al.  Quantification of cell-specific substrate uptake by probe-defined bacteria under in situ conditions by microautoradiography and fluorescence in situ hybridization. , 2003, Environmental microbiology.

[4]  J. Nielsen,et al.  Phylogenetic Identification and Substrate Uptake Patterns of Sulfate-Reducing Bacteria Inhabiting an Oxic-Anoxic Sewer Biofilm Determined by Combining Microautoradiography and Fluorescent In Situ Hybridization , 2002, Applied and Environmental Microbiology.

[5]  K. Schleifer,et al.  In Situ Characterization ofNitrospira-Like Nitrite-Oxidizing Bacteria Active in Wastewater Treatment Plants , 2001, Applied and Environmental Microbiology.

[6]  J. Nielsen,et al.  Studies on the in situ physiology of Thiothrix spp. present in activated sludge. , 2000, Environmental microbiology.

[7]  M. Cottrell,et al.  Natural Assemblages of Marine Proteobacteria and Members of the Cytophaga-Flavobacter Cluster Consuming Low- and High-Molecular-Weight Dissolved Organic Matter , 2000, Applied and Environmental Microbiology.

[8]  J. Fuhrman,et al.  Microbial Desulfurization of a Crude Oil Middle-Distillate Fraction: Analysis of the Extent of Sulfur Removal and the Effect of Removal on Remaining Sulfur , 1999, Applied and Environmental Microbiology.

[9]  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.

[10]  K. Schleifer,et al.  Combination of Fluorescent In Situ Hybridization and Microautoradiography—a New Tool for Structure-Function Analyses in Microbial Ecology , 1999, Applied and Environmental Microbiology.

[11]  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.

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

[13]  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.

[14]  R Amann,et al.  Application of a suite of 16S rRNA-specific oligonucleotide probes designed to investigate bacteria of the phylum cytophaga-flavobacter-bacteroides in the natural environment. , 1996, Microbiology.

[15]  S. Okabe,et al.  Spatial microbial distributions of nitrifiers and heterotrophs in mixed‐population biofilms , 1996, Biotechnology and bioengineering.

[16]  R. Amann.  In situ identification of micro-organisms by whole cell hybridization with rRNA-targeted nucleic acid probes , 1995 .

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

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