Interactions between yeast and bacteria lead to prion induction and stuck fermentations

Really glad we were finally able to get this paper out. Keep any eye out for a follow up paper about the fermentation performance of [GAR+] cells.

Cross-Kingdom Chemical Communication Drives a Heritable, Mutually Beneficial Prion-Based Transformation of Metabolism

Daniel F. Jarosz11, Jessica C.S. Brown1112, Gordon A. Walker, Manoshi S. Datta, W. Lloyd Ung, Alex K. Lancaster, Assaf Rotem, Amelia Chang13, Gregory A. Newby, David A. Weitz, Linda F. Bisson, Susan Lindquist

In experimental science, organisms are usually studied in isolation, but in the wild, they compete and cooperate in complex communities. We report a system for cross-kingdom communication by which bacteria heritably transform yeast metabolism. An ancient biological circuit blocks yeast from using other carbon sources in the presence of glucose. [GAR+], a protein-based epigenetic element, allows yeast to circumvent this “glucose repression” and use multiple carbon sources in the presence of glucose. Some bacteria secrete a chemical factor that induces [GAR+]. [GAR+] is advantageous to bacteria because yeast cells make less ethanol and is advantageous to yeast because their growth and long-term viability is improved in complex carbon sources. This cross-kingdom communication is broadly conserved, providing a compelling argument for its adaptive value. By heritably transforming growth and survival strategies in response to the selective pressures of life in a biological community, [GAR+] presents a unique example of Lamarckian inheritance.

Ever wonder what the difference is between Ale vs. Lager yeast?

Biochemistry, Molecular, Cellular & Developmental Biology

Despite being a yeast researcher, and supposedly having a pretty good handle on yeast genetics, I have always struggled to fully understand what the underlying genetic differences are between ale and lager yeasts. Thanks to a great article by Martha Harbison from Popsci, and research done by Libkind et al, I have finally figured it out!

Generally ales are fermented warmer with”top fermenting” yeast, and produce more fruity esters as a result. Lagers tend to be fermented cooler with “bottom fermenting” yeast, and produce more “reductive” or sulfur characters.

Ale vs. Larger

This description, while great for brewers was always unsatisfactory to me as someone with an interest in genetics and taxonomy. This was further complicated by the interchangeable use of S. calsbergensis and S. pastorianus. Top fermenting yeast are generally just plain old Saccharomyces cerevisiae. Bottom fermenting yeasts are generally more variable and have allotetraploid chromosomes, i.e. 4 chromosomes made up of mixed…

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Bisson Lab in the news for non-GMO sulfurless yeast

Bisson Lab in the news for non-GMO sulfurless yeast

Wine1W

Dr. Bisson using that expert nose

 

A winemaking yeast strain invented by a UC Davis researcher that removes the sulfur odor in wines has been patented and is undergoing development and marketing around the world and locally.

 

The non-genetically modified yeast was developed by Linda Bisson of the UCD department of viticulture and enology and is being marketed in partnership with Vancouver-based Renaissance BioScience Corp.

Local winemakers have heard of the new yeast and could be using the strain to make wine as early as this summer’s harvest, and some larger winemakers already have begun to use the new yeast in blends.

 

The yeast strain, used in fermentation to make wine, was bred through traditional methods to select for a new yeast that produces less hydrogen sulfide, which has an undesirable rotten egg smell, Bisson said. Even at low levels, hydrogen sulfide can mute the desired fruit characteristics of wines.

 

 

Biochemistry, Molecular, Cellular & Developmental Biology

Thanks to the BBC for bringing this to my attention. Using photo-activatable chromatophores and some clever fusions combined with computational control algorithms this group was able to partially control gene expression in S.cerevisiae yeast. Could be the start of something big.

http://www.bbc.co.uk/news/science-environment-15598887

Link to the paper:
In silico feedback for in vivo regulation of a gene expression circuit

Andreas Milias-Argeitis1, 4 Sean Summers1, 4 Jacob Stewart-Ornstein2, 4 Ignacio Zuleta2 David Pincus2 Hana El-Samad2 Mustafa Khammash3 John Lygeros1

 

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Biochemistry, Molecular, Cellular & Developmental Biology

Excerpt from Yeast Experiment Hints at a Faster Evolution From Single Cells

By Carl Zimmer

“The transition to multicellular life has long intrigued evolutionary biologists. The cells in our bodies have evolved to cooperate with exquisite precision. The human body has more than 200 types of cells, each dedicated to a different job. And a vast majority of the 100 trillion cells in our bodies sacrifice their own long-term legacy: Only eggs and sperm have a chance to survive our own death.

These demands for cooperation and sacrifice ought to make it hard for single-celled life to become multicellular. Yet animals, plants and other life forms have evolved bodies. “We know that multicellularity has evolved in different lineages at least 25 times in the history of life,” said William Ratcliff, a postdoctoral researcher at the University of Minnesota.

Dr. Ratcliff and his adviser, Michael Travisano, are experts in experimental evolution…

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Biochemistry, Molecular, Cellular & Developmental Biology

Here is a great resource for you! A massive glossary of viticulture and enology terms hosted by eViticulture.

Whether you are an enophile, a plant nerd, or just a casual wine drinker there are definitions on here that will increase your depth of understanding, and maybe even lead to some better questions next time you go wine tasting!

Here are some examples from the glossary:

Bilateral cordon: Extensions of the trunk in the form of two permanent horizontal branches each supported by a wire, extending in opposite directions and from which fruiting positions originate. Examples are high cordon, with downward shoot orientation, and low cordon, with vertical shoot positioning.

Botrytis: Botrytis bunch rot or gray mold is a fungal disease that infects fruits and occasionally shoots and leaves; caused by Botrytis cinerea. The benevolent form is known as “noble rot” and is responsible for some of the…

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