Science & Technology
; Life Sciences & Biomedicine
Environmental Sciences & Ecology
Denitrification is of great concern as part of the global nitrogen cycle leading to nitrogen loss from lake. However key factors controlling this process still remain unclear. A shallow Chinese lake (Lake QingLing) is divided into aquaculture zone (QLN) and natural zone covered by macrophytes (QLS), providing an ideal model to identify environment factors, rather than geographical and hydrological ones, affecting community structure of denitrifiers. Targeting the nirS gene and using the terminal restriction fragment length polymorphism (T-RFLP) analysis and cloning composition structure of denitrifiers were studied in sediment of Lake QingLing. Trophic states were largely different between the two basins. In parallel, a few unique T-RFs appeared in QLN. Furthermore, most sequences were grouped into Proteobacteria, majority genes from QLN were found to be prevalent in Alphaproteobacteria and Gammaproteobacteria while most sequences from QLS were in Betaproteobacteria and Gammaproteobacteria. Canonical correspondence analysis (CCA) indicated that organic matter (OM) in sediment, NH4+ and pH value in pore water were important environmental factors shaping these communities.