Microbiological mechanism of swine excreta odor production and control

The generation of swine excreta odors is a complex microbiological process of incomplete anaerobic degradation of carbohydrates, proteins, and lipid components in wastes. Understanding bacterial genera indigenous to swine excreta and their potential for odorous compound production is essential for developing effective odor control techniques. This review covers available information in recent decades that is related to main bacterial genera indigenous to swine excreta, role of different bacterial genera in odorous compound production, origin of excreta odor, odor indicator and related bacterial genera, and microbiological mechanisms and control techniques. However, due to the makeup and complexity of odorous compounds and the subjectivity of odor evaluation, further research is required on related studies of swine excreta odor indicators. Furthermore, several bacteria genera are anaerobic or facultative anaerobic, and therefore cannot form pure cultures by ordinary streak plate method. Combination of well developed classical anaerobic microbiological techniques with modern molecular techniques, along with dynamic understanding of growth status and mode of odor production by different bacteria genera is critical for successful future studies.