Prokaryotic successions and diversity in composts as revealed by 454-pyrosequencing.

In this study, 454-pyrosequencing was applied to analyze prokaryotic patterns in three lignocellulosic composting systems across the three main phases. In all composts, diversity expanded as composting progressed. Communities in the mesophilic- and mature-phases of all composts were distinct, which did not support the concept that organisms present in the mesophilic phase enter dormancy during thermophilic period, and re-colonize the compost at the mature phase. Analysis of similarity revealed compost phase was a significant source of dissimilarity (p=0.011), compost type was not (p=0.401). Analysis of variance also showed significant phase effects on the abundance of (p-value): Archaea (0.001), Planctomycetes (0.002), Chloroflexi (0.016), Deltaproteobacteria (0.027), Bacteria (0.046) and Gammaproteobacteria (0.056). Mature-phase compost was a preferred niche for the Archaea, Planctomycetes, Chloroflexi and Deltaproteobacteria, while Gammaproteobacteria were predominant in earlier phases. Thus, the mature phase pattern could have implications in the development of biomarker assays for compost maturity.