Recombinant bacterium boosts production of compound that can relieve menopause symptoms

January 26, 2016

A soy isoflavone derivative that goes by the scientific moniker, (S)-equol, has proven potent for mitigating menopausal symptoms. However, it has been impossible to produce in quantities sufficient for widespread commercial nutraceutical production. But now, a team of Korean researchers reports having constructed a recombinant bacterium which they say can boost production. The research is published January 22nd in Applied and Environmental Microbiology, a journal of the American Society for Microbiology.

Equol is produced naturally in small quantities by the human intestine-abiding bacterium, Slackia isoflavoniconvertens. Clinical studies have shown that this compound reduces hot flashes, night sweats, bone loss, and other , with no harmful side effects, and studies in several human cell lines suggest that it might eventually prove to prevent prostate cancer. But the anaerobic S. isoflavoniconvertens' productivity was too low for large-scale production, and that bacterium doesn't work well with industrial fermenters, said lead investigator Byung-Gee Kim, PhD, a professor in the Department of Chemical and Biological Engineering, Seoul National University, Seoul, Korea.

To increase production of (S)-equol, the investigators cloned the enzymes of the compound's into a strain of the laboratory bacterium, Escherichia coli, which is commonly used, among other things, for industrial purposes. But although this bacterium enabled easier control of production, and although the investigators assembled optimum environmental conditions for the , including its preferred acidity level and temperature, the yield still remained too low for commercial production, said Kim.

The researchers then tried another way to raise production. They identified the rate-determining enzyme in the biosynthetic pathway. "We replaced the slower, naturally-occurring enzyme with a mutant version of that enzyme, which is faster," said Kim.

The mutant enzyme has substantially increased production of (S)-equol. However, the process has yet to achieve sufficient productivity for industrial production, said Kim. "We showed a partial success, and we are working to improve it."

Explore further: Soy spells fewer hot flashes for certain women

More information: Pyung-Gang Lee et al. P212A mutant of dihydrodaidzein reductase enhances ( )-equol productivity and enantioselectivity in recombinant whole cell reaction system , Applied and Environmental Microbiology (2016). DOI: 10.1128/AEM.03584-15

Related Stories

Soy spells fewer hot flashes for certain women

November 18, 2014

Does soy in the diet help with hot flashes? It does, but only for women whose bodies can produce the soy metabolite equol, reports a study of American women just published online in Menopause, the journal of The North American ...

Recommended for you

The astonishing efficiency of life

November 17, 2017

All life on earth performs computations – and all computations require energy. From single-celled amoeba to multicellular organisms like humans, one of the most basic biological computations common across life is translation: ...

Unexpected finding solves 40-year old cytoskeleton mystery

November 17, 2017

Scientists have been searching for it for decades: the enzyme that cuts the amino acid tyrosine off an important part of the cell's skeleton. Researchers of the Netherlands Cancer Institute have now identified this mystery ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.