Enviromental PH effects on denitrification of soil bacteria and their transcriptional genes

Abstract EN

The pH effect on denitrification in soil bacteria of environmental samples was investigated from Norwegian (Torp rejion), to explore the control of pH on the regulation of denitrification, quantified the functional genes nosZ (encoding for nitrous oxide reductase) and nirS (encoding for nitrite oxide reductase) and their transcripts during transition from oxic to anoxic conditions.

Soil samples from field experiments from treated Norwegian soil (pH 7.5) were compared, adapted in to two different pH levels (pH 6 and pH 7).

The kinetic of gas transformations (O2, NO, N2O and N2) were monitored using a robotic incubation system.

The results were interpreted in relation to the kinetics of NO, N2O and N2 production and compared with previousl data, obtained from similar experiment.

The number of bacteria that were recovered on the Nycodenz cushion was estimated and compared with the total number of bacteria / g soil (using SYBR-green I).

RNA was reverse transcribed to cDNA and quantified using real time PCR and quantified to indicate the transcriptional activity of the functional genes at the time of sampling.

PCR-DGGE used to study the complex bacterial community of the denitrification genes and the composition of their transcripts.

The experimental results showed that denitrification is affected by acidic pH environments.

The transcription levels of the nirS and nosZ genes, were notably lower at pH 6 than at pH 7The study showed that NO produced during low transcription of nirS but no N2 produced when transcription of nosZ.