Researchers from
the Nara Institute of Science and Technology and the Nara Prefecture Institute
of Industrial Development have revealed that a mutant strain of sake yeast
produces 10 times the amount of the amino acid ornithine compared with the
parent yeast strain.
Ornithine is a
non-protein-making amino acid and a precursor to two amino acids -- arginine
and proline. It has been found to perform several physiological functions, such
as reducing fatigue and improving sleep quality.
To find
ethanol-tolerant yeast strains, the researchers isolated mutants that
accumulated proline, which can alleviate ethanol toxicity, using a conventional
mutagenesis (i.e., one that doesn't involve genetic modification). They also
conducted whole genome sequencing analysis, and performed brewing tests with
sake yeast strains. Then they identified and analyzed a new mutation in a gene
that encodes a variant of N-acetyl glutamate kinase that increases intracellular
ornithine level.
The results of this
study
will contribute to the development of improved yeast strains for production of
high levels of ornithine, and the strain obtained in this study could be
readily applied to sake, wine, and beer brewing. Ornithine-accumulating yeast
strains could also be used in the production of ornithine-rich dietary
supplements made from these yeasts and their products.
See:
Masataka Ohashi, Ryo Nasuno, Shota Isogai, Hiroshi Takagi. High-level production of ornithine by expression of the feedback inhibition-insensitive N-acetyl glutamate kinase in the sake yeast Saccharomyces cerevisiae. Metabolic Engineering, 2020; 62: 1 DOI: 10.1016/j.ymben.2020.08.005
No comments:
Post a Comment
Pharmaceutical Microbiology Resources