Submitted to: American Society for Microbiology
Publication Type: Abstract Only
Publication Acceptance Date: August 9, 1999
Publication Date: N/A
Technical Abstract: Storage of swine waste is associated with the production of a variety of odorous compounds, including ammonia, organic acids and alcohols, and sulfides. Although generation of these chemicals is the result of microbiological activity, little is known about the types of microorganisms responsible for their production. Microbial populations of pig feces and waste storage pits were analyzed by conventional microbiological methods and 16S rDNA sequence analyses. Fecal and waste storage pit samples were collected from a local swine production facility. Samples were plated onto complex media containing either rumen fluid or swine waste slurry. Samples were also plated onto media containing tetracycline, erythromycin, or tylosin and antibiotic resistant bacteria enumerated. Antibiotic resistant organisms were found in all samples. These data suggest that stored swine waste may serve as a reservoir of antibiotic resistance genes. Randomly selected colonies from the highest dilutions were isolated. Similarity analyses of 16S rDNA sequences derived from the bacteria indicated the presence of primarily low G+C Gram-positive bacteria, as well as a variety of unidentified bacteria. Total DNA was also isolated from the fecal and pit samples. DNA sequence analyses of PCR amplified 16S rDNA genes from the DNA samples were carried out. Similarity analyses of the 16S sequences again indicated the presence of primarily low G+C Gram-positive bacteria. However, differences in the sequences suggest an ecological shift between the feces and the stored waste. The finding of a number of unidentified eubacteria and archaebacteria suggests that stored animal waste may be a new source of microbial biodiversity and novel microorganisms, as well as a potential reservoir of antibiotic resistance genes.