‘New’ bacteria discovery could yield clues to controlling pig manure stink


PEORIA, Ill. – Scientists here and in Britain have identified and named a newly discovered genus of bacteria that could provide clues to reducing the distinctive aroma of pig manure.

“Hespellia” is the name of a new genus of bacteria discovered by USDA’s Agricultural Research Service and cooperating scientists and posthumously named in honor of ARS microbiologist Robert B. Hespell.

Biochemical fingerprint. A genus is a specific taxonomic group of closely related species.

Scientists from the ARS National Center for Agricultural Utilization Research in Peoria, Ill., and the University of Reading in the United Kingdom concluded the genus was previously unidentified after comparing the bacteria’s ribosomal gene to other species and analyzing the microbes’ biochemical features.

The team discovered the Hespellia bacteria while cataloging microbial species that inhabit swine manure and produce its offending odor.

Collecting such information can yield important clues for figuring out new ways of diminishing the odors, according to ARS microbiologist Terence R. Whitehead, a member of USDA’s Fermentation Biotechnology Research Unit.

Control possibilities. New pig feed formulations with improved digestibility and novel waste-handling systems are two possibilities.

Besides sulfides that contribute to swine manure’s stink, the waste also emits gases like ammonia and methane that can be environmentally harmful, notes Whitehead.

Pioneering studies. He credits Hespell, who worked at the Peoria lab until his death in August 1998, with pioneering studies on the scientific description of anaerobic bacteria and their use in improving digestion in the rumen of cows and sheep.

Anaerobes are organisms that thrive in oxygen-free environments – including those outside of animal hosts, such as manure storage pits and lagoons where manure is treated for use as fertilizer.


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