Tag Archives: yeast

Use kombucha to produce bacterial cellulose

The combination of the US Army, bacterial cellulose, and kombucha seems a little unusual. However, this January 26, 2021 U.S. Army Research Laboratory news release (also on EurekAlert) provides some clues as to how this combination makes sense,

Kombucha tea, a trendy fermented beverage, inspired researchers to develop a new way to generate tough, functional materials using a mixture of bacteria and yeast similar to the kombucha mother used to ferment tea.

With Army funding, using this mixture, also called a SCOBY, or symbiotic culture of bacteria and yeast, engineers at MIT [Massachusetts Institute of Technology] and Imperial College London produced cellulose embedded with enzymes that can perform a variety of functions, such as sensing environmental pollutants and self-healing materials.

The team also showed that they could incorporate yeast directly into the cellulose, creating living materials that could be used to purify water for Soldiers in the field or make smart packaging materials that can detect damage.

“This work provides insights into how synthetic biology approaches can harness the design of biotic-abiotic interfaces with biological organization over multiple length scales,” said Dr. Dawanne Poree, program manager, Army Research Office, an element of the U.S. Army Combat Capabilities Development Command, now known as DEVCOM, Army Research Laboratory. “This is important to the Army as this can lead to new materials with potential applications in microbial fuel cells, sense and respond systems, and self-reporting and self-repairing materials.”

The research, published in Nature Materials was funded by ARO [Army Research Office] and the Army’s Institute for Soldier Nanotechnologies [ISN] at the Massachusetts Institute of Technology. The U.S. Army established the ISN in 2002 as an interdisciplinary research center devoted to dramatically improving the protection, survivability, and mission capabilities of the Soldier and Soldier-supporting platforms and systems.

“We foresee a future where diverse materials could be grown at home or in local production facilities, using biology rather than resource-intensive centralized manufacturing,” said Timothy Lu, an MIT associate professor of electrical engineering and computer science and of biological engineering.

Researchers produced cellulose embedded with enzymes, creating living materials that could be used to purify water for Soldiers in the field or make smart packaging materials that can detect damage. These fermentation factories, which usually contain one species of bacteria and one or more yeast species, produce ethanol, cellulose, and acetic acid that gives kombucha tea its distinctive flavor.

Most of the wild yeast strains used for fermentation are difficult to genetically modify, so the researchers replaced them with a strain of laboratory yeast called Saccharomyces cerevisiae. They combined the yeast with a type of bacteria called Komagataeibacter rhaeticus that their collaborators at Imperial College London had previously isolated from a kombucha mother. This species can produce large quantities of cellulose.

Because the researchers used a laboratory strain of yeast, they could engineer the cells to do any of the things that lab yeast can do, such as producing enzymes that glow in the dark, or sensing pollutants or pathogens in the environment. The yeast can also be programmed so that they can break down pollutants/pathogens after detecting them, which is highly relevant to Army for chem/bio defense applications.

“Our community believes that living materials could provide the most effective sensing of chem/bio warfare agents, especially those of unknown genetics and chemistry,” said Dr. Jim Burgess ISN program manager for ARO.

The bacteria in the culture produced large-scale quantities of tough cellulose that served as a scaffold. The researchers designed their system so that they can control whether the yeast themselves, or just the enzymes that they produce, are incorporated into the cellulose structure. It takes only a few days to grow the material, and if left long enough, it can thicken to occupy a space as large as a bathtub.

“We think this is a good system that is very cheap and very easy to make in very large quantities,” said MIT graduate student and the paper’s lead author, Tzu-Chieh Tang. To demonstrate the potential of their microbe culture, which they call Syn-SCOBY, the researchers created a material incorporating yeast that senses estradiol, which is sometimes found as an environmental pollutant. In another version, they used a strain of yeast that produces a glowing protein called luciferase when exposed to blue light. These yeasts could be swapped out for other strains that detect other pollutants, metals, or pathogens.

The researchers are now looking into using the Syn-SCOBY system for biomedical or food applications. For example, engineering the yeast cells to produce antimicrobials or proteins that could benefit human health.

Here’s a link to and a citation for the paper,

Living materials with programmable functionalities grown from engineered microbial co-cultures by Charlie Gilbert, Tzu-Chieh Tang, Wolfgang Ott, Brandon A. Dorr, William M. Shaw, George L. Sun, Timothy K. Lu & Tom Ellis. Nature Materials (2021) DOI: https://doi.org/10.1038/s41563-020-00857-5 Published: 11 January 2021

This paper is behind a paywall.

Chemicals that slow biological aging in yeast might help humans too

A March 15, 2016 Concordia University (Montréal, Canada) news release (also on EurekAlert) describes research that may slow the aging process (Note: Links have been removed),

Even though the search for the Fountain of Youth dates back to the ancient Greeks, the quest to live forever continues today. Indeed, it has been said that the ability to slow the aging process would be the most important medical discovery in the modern era.

A new study published in the journal Oncotarget by researchers from Concordia and the Quebec-based biotech company Idunn Technologies may have uncovered an important factor: plant extracts containing the six best groups of anti-aging molecules ever seen.

For the study, the research team combed through Idunn Technologies’ extensive biological library, conducting more than 10,000 trials to screen for plant extracts that would increase the chronological lifespan of yeast.

Why yeast? Cellularly speaking, aging progresses similarly in both yeast and humans. It’s the best cellular model to understand how the anti-aging process takes place.

“In total, we found six new groups of molecules that decelerate the chronological aging of yeast,” says Vladimir Titorenko, the study’s senior author and a professor in the Department of Biology at Concordia. He carried out the study with a group of Concordia students and Éric Simard, the founder of Idunn Technologies, which is named for the goddess of rejuvenation in Norse mythology.

This has important implications not only for slowing the aging process, but also for preventing certain diseases associated with aging, including cancer.

“Rather than focus on curing the individual disease, interventions on the molecular processes of aging can simultaneously delay the onset and progression of most age-related disorders. This kind of intervention is predicted to have a much larger effect on healthy aging and life expectancy than can be attained by treating individual diseases,” says Simard, who notes that these new molecules will soon be available in commercial products.

“These results also provide new insights into mechanisms through which chemicals extracted from certain plants can slow biological aging,” says Titorenko.

One of these groups of molecules is the most potent longevity-extending pharmacological intervention yet described in scientific literature: a specific extract of willow bark.

Willow bark was commonly used during the time of Hippocrates, when people were advised to chew on it to relieve pain and fever. The study showed that it increases the average and maximum chronological lifespan of yeast by 475 per cent and 369 per cent, respectively. This represents a much greater effect than rapamycin and metformin, the two best drugs known for their anti-aging effects.

“These six extracts have been recognized as non-toxic by Health Canada, and already exhibit recognized health benefits in humans,” says Simard.

“But first, more research must be done. That’s why Idunn Technologies is collaborating with four other universities for six research programs, to go beyond yeast, and work with an animal model of aging, as well as two cancer models.”

A rather interesting image was included with the news release,

The Fountain of Youth, a 1546 painting by Lucas Cranach the Elder. Courtesy: Concordia University

The Fountain of Youth, a 1546 painting by Lucas Cranach the Elder. Courtesy: Concordia University

There’s also this,

An extract of willow bark has shown to be one of the most potent longevity-extending pharmacological interventions yet described in scientific literature. Courtesy: Concordia University

An extract of willow bark has shown to be one of the most potent longevity-extending pharmacological interventions yet described in scientific literature. Courtesy: Concordia University

Here’s a link to and a citation for the paper,

Discovery of plant extracts that greatly delay yeast chronological aging and have different effects on longevity-defining cellular processes by Vicky Lutchman, Younes Medkour, Eugenie Samson, Anthony Arlia-Ciommo, Pamela Dakik, Berly Cortes, Rachel Feldman, Sadaf Mohtashami, Mélissa McAuley, Marisa Chancharoen, Belise Rukundo, Éric Simard, Vladimir I. Titorenko. DOI: 10.18632/oncotarget.7665 Published: February 24, 2016

This appears to be an open access paper.

You can find out more about Idunn Technologies here but you will need French language reading skills as the English language version of the site is not yet available.