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United States Department of Agriculture

Agricultural Research Service

Research Project: UNDERSTANDING THE ROLE OF COMMENSAL ANAEROBIC BACTERIA IN ODOR, EMISSIONS, AND ANTIBIOTIC RESISTANCE FROM STORED LIVESTOCK MANURE

Location: Bioenergy Research Unit

Title: Inhibition of hydrogen sulfide, methane, and total gas production and sulfate-reducing bacteria in in vitro swine manure by tannins, with focus on condensed quebracho tannins

Authors
item Whitehead, Terence
item Spence, Cheryl -
item Cotta, Michael

Submitted to: Applied Microbiology and Biotechnology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 31, 2012
Publication Date: November 13, 2012
Citation: Whitehead, T.R., Spence, C., Cotta, M.A. 2013. Inhibition of hydrogen sulfide, methane, and total gas production and sulfate-reducing bacteria in in vitro swine manure by tannins, with focus on condensed quebracho tannins. Applied Microbiology and Biotechnology. 97:8403-8409.

Interpretive Summary: The present research determined that the addition of condensed tannins from the quebracho tree to swine manure slurries in the laboratory significantly reduces the production of greenhouse gases and odorous compounds and the bacteria that can produce the emissions. Management practices from large-scale swine production facilities have resulted in the increased collection and storage of manure for off-season fertilization use. Odor and emissions produced during storage have increased the tension among rural neighbors and among urban and rural residents. Production of these compounds from stored manure is the result of microbial activity of the anaerobic bacteria populations during storage. The inhibitory effects of condensed quebracho tannins on in vitro swine manure for reduction of microbial activity and reduced production of gaseous emissions, including the toxic odorant hydrogen sulfide produced by sulfate-reducing bacteria was determined. Significant reductions in each of these parameters were observed during the 28-day study. The addition of condensed tannins to stored swine manure should benefit the swine producer and surrounding residents by reducing production of odorous compounds and also benefit the environment by reducing greenhouse gas production from swine facilities.

Technical Abstract: Management practices from large-scale swine production facilities have resulted in the increased collection and storage of manure for off-season fertilization use. Odor and emissions produced during storage have increased the tension among rural neighbors and among urban and rural residents. Production of these compounds from stored manure is the result of microbial activity of the anaerobic bacteria populations during storage. In the current study the inhibitory effects of condensed quebracho tannins on in vitro swine manure for reduction of microbial activity and reduced production of gaseous emissions, including the toxic odorant hydrogen sulfide produced by sulfate-reducing bacteria (SRB) was examined. Swine manure was collected from a local swine facility, diluted in anaerobic buffer and mixed with 1% w/v fresh feces. This slurry was combined with quebracho tannins and total gas and hydrogen sulfide production was monitored over time. Aliquots were removed periodically for isolation of DNA to measure the SRB populations using quantitative PCR. Addition of tannins reduced overall gas, hydrogen sulfide and methane production by greater than 90% after seven days of treatment, and continued to at least 28 days. SRB population was also significantly decreased by tannin addition. qRT-PCR of 16S rDNA bacteria genes showed that the total bacterial population was also decreased in these incubations. These results indicate that the tannins elicited a collective effect on the bacterial population, and also suggest a reduction in the population of methanogenic microorganisms as demonstrated by reduced methane production in these experiments. Such a generalized effect could be extrapolated to a reduction in other odor-associated emissions during manure storage.

Last Modified: 9/21/2014
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