Search results for "DENITRIFIERS"
showing 3 items of 3 documents
Shifts in size, genetic structure and activity of the soil denitrifier community by nematode grazing
2010
International audience; Bacterial-feeding nematodes represent an important driver of the soil microbial activity and diversity. This study aimed at characterizing the impact of nematode grazing on a model functional bacterial guild involved in N-cycling, the denitrifiers. Bacterial-feeding nematodes (Cephalobus pseudoparvus) were inoculated into soil microcosms whose indigenous nematofauna had previously been removed. The size, genetic structure and activity of the soil denitrifier community were characterized 15 and 45 days after nematodes inoculation using quantitative PCR of the nirK, nirS and nosZ denitrification genes, fingerprinting of the nirK and nirS genes and denitrification enzym…
Molecular tools to assess the diversity and density of denitrifying bacteria in their habitats
2007
Publisher Summary This chapter describes the molecular tools to assess the diversity and density of denitrifying bacteria in their habitats. Genome sequencing and metagenomic projects might even provide new denitrification gene sequences, which could aid in designing more broad range primers. Most information is obtained by cloning and sequencing the polymerase chain reaction (PCR) amplicons, but a more rapid analysis is achieved using fingerprinting techniques. As all PCR-based analyses, the fingerprinting techniques are subjected to well-known biases introduced by, e.g., DNA extraction procedures, primer selection, and PCR conditions. For denitrifiers, the PCR-RFLP (restriction fragment l…
Determinants of the distribution of nitrogen-cycling microbial communities at the landscape-scale
2010
Little information is available regarding the landscape-scale distribution of microbial communities and its environmental determinants. However, a landscape perspective is needed to understand the relative importance of local and regional factors and land management for the microbial communities. In this manuscript, we investigated the distribution of functional microbial communities involved in N-cycling and of the total bacterial and crenarchaeal communities over 107 sites using a grid with a 16 km lag distance within Burgundy, a 31 500 km2 region in France. After quantifying the abundances of the total bacterial, crenarchaeal, nitrate-reducing, denitrifying and ammonia-oxidizing communit…