TY - JOUR

T1 - A comparison of ammonia-oxidiser populations in eutrophic and oligotrophic basins of a large freshwater lake

AU - Whitby, Corinne B.

AU - Saunders, Jon R.

AU - Pickup, Roger W.

AU - McCarthy, Alan J.

PY - 2001/6/30

Y1 - 2001/6/30

N2 - A combination of PCR amplification and oligonucleotide probing was used to investigate the populations of ammonia-oxidisers of the β-Proteobacteria in the eutrophic and oligotrophic basins of Lake Windermere, a large temperate lake in the English Lake District. Numbers of ammonia-oxidisers (MPN) in the Windermere lakewater were low (< 100 cells m1-1) throughout the year with the exception of peaks in August, which coincided with stratification, and November in the South Basin where overturn may have introduced ammonia-oxidising bacteria into the water column. Sediment samples contained larger populations of ammonia oxidisers, usually ca. 104 per g. dry weight, which remained relatively constant throughout the seasonal cycle in both Basins. DNA was recovered from lakewater and sediment samples and Nitrosospira and N. europaea-eutropha lineage 16S rRNA genes amplified in a nested PCR reaction, with confirmation of identity by oligonucleotide hybridisation. Nitrosospira 16S rDNA was readily detected in all samples and therefore found to be ubiquitous. In contrast, nitrosomonad DNA of the N. europaea-eutropha lineage could only be detected in the oligotrophic North Basin. Enrichment cultures of lakewater samples only exhibited nitrification at low (0.67 mM) and medium (5 mM) ammonium concentrations, whilst sediment enrichments nitrified at all concentrations tested including high (12.5 mM) ammonium medium. These data suggest that ammonia-oxidiser populations may be physiologically distinguished between lakewater and sediment, and that species distribution in a single lake is non-uniform.

AB - A combination of PCR amplification and oligonucleotide probing was used to investigate the populations of ammonia-oxidisers of the β-Proteobacteria in the eutrophic and oligotrophic basins of Lake Windermere, a large temperate lake in the English Lake District. Numbers of ammonia-oxidisers (MPN) in the Windermere lakewater were low (< 100 cells m1-1) throughout the year with the exception of peaks in August, which coincided with stratification, and November in the South Basin where overturn may have introduced ammonia-oxidising bacteria into the water column. Sediment samples contained larger populations of ammonia oxidisers, usually ca. 104 per g. dry weight, which remained relatively constant throughout the seasonal cycle in both Basins. DNA was recovered from lakewater and sediment samples and Nitrosospira and N. europaea-eutropha lineage 16S rRNA genes amplified in a nested PCR reaction, with confirmation of identity by oligonucleotide hybridisation. Nitrosospira 16S rDNA was readily detected in all samples and therefore found to be ubiquitous. In contrast, nitrosomonad DNA of the N. europaea-eutropha lineage could only be detected in the oligotrophic North Basin. Enrichment cultures of lakewater samples only exhibited nitrification at low (0.67 mM) and medium (5 mM) ammonium concentrations, whilst sediment enrichments nitrified at all concentrations tested including high (12.5 mM) ammonium medium. These data suggest that ammonia-oxidiser populations may be physiologically distinguished between lakewater and sediment, and that species distribution in a single lake is non-uniform.

KW - 16S rRNA

KW - Ammonia-oxidising bacteria

KW - Nitrification

U2 - 10.1023/A:1010202211368

DO - 10.1023/A:1010202211368

M3 - Journal article

C2 - 11520004

AN - SCOPUS:0034885539

VL - 79

SP - 179

EP - 188

JO - Antonie van Leeuwenhoek, International Journal of General and Molecular Microbiology

JF - Antonie van Leeuwenhoek, International Journal of General and Molecular Microbiology

SN - 0003-6072

IS - 2

ER -