Submitted to: Microbial Ecology International Symposium
Publication Type: Abstract Only
Publication Acceptance Date: August 27, 2004
Publication Date: N/A
Technical Abstract: Storage of swine manure from large-scale swine facilities results in the microbiological production of a variety of odorous compounds, including ammonia, organic acids and alcohols, sulfides, and phenolics. Such odors can create a nuisance to local populace and may contribute to health problems for swine facility workers and animals. Production of skatole (3-methylindole) from tryptophan by swine intestinal bacteria can adversely affect the taste and aroma of the meat and skatole production during long-term storage of swine manure can add to the malodors from large-scale swine facilities. No skatole-producing bacteria have been identified from the swine gastrointestinal tract or stored manure. Therefore, potential skatole-producing bacteria were isolated from stored swine manure by enrichment using medium containing tryptone and tryptophan (TT medium) as energy sources. Serial dilutions from stored swine manure were performed with TT medium and incubated under anaerobic conditions. Pure cultures from the enrichments were isolated by streaking onto TT-agar medium and screened for production of skatole by gas chromatography analysis. Thirteen strains were identified that produced skatole. All were Gram-positive, anaerobic bacteria. 16S rDNA sequence analyses indicated a number were closely related to Clostridium botulinum/C. sporagenes, while others were less closely associated with Peptostreptococcus/Peptoniphilus species. Several of the isolates may represent unidentified genera. Skatole production by all isolates was dramatically reduced when tryptophan was removed from the medium. This is the first report of isolation and identification of skatole-producing bacteria from swine.