Stimulation of different functional groups of bacteria by various plant residues as a             driver of soil priming effect
The decomposition of two 13C labeled crop residues (wheat and                 alfalfa) and the dynamics of the genetic structure and taxonomic composition of the                 soil bacterial communities decomposing 13C labeled FOM and native unlabeled Soil                 Organic Matter(SOM)have been investigated.
Primers 530F (xxxxGTGCCAGCMGCNGCGG) and 803R                     (xxxxCTACCNGGGTATCTAAT) were used to amplify a 16S rRNA gene fragment of the                     appropriate size and sequence variability for 454 pyrosequencing, and xxxx was                     designed for the sample identification barcoding key recommended by the                     manufacturer (Beckman Coulter Genomics). For each treatment and sampling date                     analyzed, DNA extracted from the three replicates was pooled to perform the PCR.                     2 ng aliquots of DNA from each pool were used for a 50 ֬ PCR reaction under the                     following conditions: 95у for 3 min, 30 cycles of 1 min at 95у (denaturation),                     55у for 30 s (annealing) and 72у for 30 s (extension), followed by 5 min at 72у.                     For each sample, amplicons of five replicated PCRs were purified using a                     MinElute gel extraction kit (Qiagen, Courtaboeuf, France) following the                     manufacturer's protocol. On 300 ng per sample, adapter sequences were added by                     the manufacturer and pyrosequencing was carried out on a Genome Sequencer Flx                     454 (Beckman Coulter Genomics). The 16S rRNA fragments provided were mainly                     between 250 and 300 bp.