Characterization and spatial distribution of bacterial communities within passively aerated cattle manure composting piles.

The bacterial communities in the core, bottom, top, middle-surface, and lower-surface full-scale passively aerated cattle manure compost was investigated using DGGE of PCR-amplified 16S rRNA sequences. Some Bacillus species and strictly anaerobic thermophilic Clostridium species were dominant only in the core and bottom zones. In contrast, bands belonging to mesophilic bacteria such as Bacteroidetes, Clostoridia,alpha and gamma-proteobacteria were detected in surface zones, even in the initial thermophilic stage of the process. Our results clearly show the spatial distribution of the microbial community within full-scale composting piles, which indicates N or C conversion by zone-specific bacterial communities were occurring in each zone of the pile.