[ad_1]
Alcohol was celebrated for all the history. The ancient Greeks venerated Dionysus for their spirits, while the Chinese recognized Yidi as the creator of the libertine drink. Of course, without knowing it, both were actually servants of the real master alcohol, yeast. In Japan, some of the best sakes are the result of a single yeast mutation. Researchers at the Nara Institute of Science and Technology (NAIST) report a new study published in Applied and environmental microbiology the key molecule released by this mutation, PP2AB55δ, allows the yeast to ferment alcohol.
Assistant Professor Daisuke Watanabe and Professor Hiroshi Takagi have devoted their careers to studying yeast mutations to determine why some are better at fermentation than others. An example of this is the RIM15 gene in Kyokai sake yeast number 7.
"RIM15 codes for RIM15p and RIM15p inhibits alcoholic fermentation. However, even after correcting the mutation, Kyokai number 7 can still ferment, "says Watanabe.
This fact suggested that other molecules working with RIM15p are also involved in fermentation. Further badysis revealed that Kyokai's number 7 has two unusual molecular characteristics, in addition to the RIM15 mutation.
"We have seen high TORC1 activity," says Watanabe. TORC1 is known to inhibit RIM15p.
Ironically, fermentation causes stress on the yeast, which can cause cell death. To conserve energy, the yeasts stop growing, which implies reduced fermentation activity. "This high activity of TORC1 seems new to sake yeast cells," says Watanabe.
Where TORC1 is a molecule that removes RIM15p, the second factor is a molecule released by RIM15p inhibition.
"CDC55 encodes B55δ, a sub-unit of regulation, on PP2A[PP2A[PP2A[PP2A[PP2AB55δ]. The mutation of this gene resulted in a yeast that could no longer ferment alcohol, "notes Watanabe. RIM15p was inhibited, suggesting that PP2AB55δ is an important regulator of the fermentation of alcohol by yeast.
By understanding all the molecules involved in the fermentation of alcohol and their interactions, Watanabe is optimistic that it will be possible to improve fermentation by targeting individual steps of the process.
"We hypothesize that the high activity of TORC1 and the loss of RIM15p contribute to the activation of PP2AB55δ. This discovery suggests a critical molecular pathway for fermentation of alcohol by yeast. By studying the different steps, we can identify ways to chemically improve the production, "he said.
Source of the story:
Material provided by Nara Institute of Science and Technology. Note: Content can be changed for style and length.
Source link
