Phylogenetic diversity of methanogenic archaea in swine waste storage pits

Total DNA was isolated from swine feces and a swine waste storage pit and used as templates for PCR amplification of archaeal 16 rDNA using specific primers. Only the sample from the center of the waste pit produced a PCR product. DNA sequence analyses of random clones demonstrated a variety of methanogenic archaea. Six groups of sequences were identified, including those similar to Methanobrevibacter sp., Methanocorpusculum sp., and Methanoculleus sp. Three groups of sequences represented unidentified organisms. These data suggest that swine waste storage pits may represent an untapped source of novel methanogenic archaea.