Swiss chemists emulate cheese rind to create self-cleaning surface material

January 9, 2012 by Bob Yirka, report
Camembert cheese. Image: wikipedia

( -- Cheese lovers know that the milky white outer coating of Camembert cheese not only serves to offer a tart offset to the pungent inner cheese, but also protects it until ready to be eaten, much like plastic wrap does for other foods. Now, a group of Swiss researchers have taken this idea heart, and have created a sort of artificial rind. As they describe in their paper published in the Proceedings of the National Academy of Sciences, they have created a bio-sandwich of sorts using a type of cheese fungus to create a material that eats organic material that comes into contact with it.

The idea was to create a material that mimics what the rind does for Camembert cheese, i.e. protect it from other , while at the same time allowing the cheese inside to mature. To construct such a material, they started with a sheet of thin plastic which they covered with Penicillium roqueforti, a mixture known more familiarly as the stuff that makes blue. They then covered that with a type of that was just porous enough to keep the fungus in while still allowing liquids to pass through. And that was all it took. To test their new material, they dropped a little bit of a sugar solution onto the material, then sat back to watch what happened. Though it took two weeks, the sugar was completely eaten by the fungus, leaving the newly created material, sparkling clean.

Perhaps what was even more compelling was that the fungus went back to being dormant after it had eaten the sugar, meaning it could conceivably sit there indefinitely, only coming alive, so to speak, when once again food is dropped onto it. All that is necessary to keep it from dying, is to ensure that it doesn’t ever dry out completely. Thus, all that’s needed is a small amount of moisture in the air around it.

The whole concept seems so basic, it’s hard to understand why no one has thought of creating such materials before. What if self-cleaning countertops were made of such material for example, keeping them forever free of dangerous bacteria, or thinking bigger, as the team suggests, what if the surface of skyscrapers were covered in such a sandwich but instead of blue cheese fungus, algae could be used to convert carbon dioxide to oxygen. Clearly, this simple idea could lead to truly revolutionary new types of material coverings.

Explore further: Heart-healthy yak cheese

More information: Incorporating microorganisms into polymer layers provides bioinspired functional living materials, PNAS January 3, 2012 vol. 109 no. 1 90-94. doi: 10.1073/pnas.1115381109

Artificial two-dimensional biological habitats were prepared from porous polymer layers and inoculated with the fungus Penicillium roqueforti to provide a living material. Such composites of classical industrial ingredients and living microorganisms can provide a novel form of functional or smart materials with capability for evolutionary adaptation. This allows realization of most complex responses to environmental stimuli. As a conceptual design, we prepared a material surface with self-cleaning capability when subjected to standardized food spill. Fungal growth and reproduction were observed in between two specifically adapted polymer layers. Gas exchange for breathing and transport of nutrient through a nano-porous top layer allowed selective intake of food whilst limiting the microorganism to dwell exclusively in between a confined, well-enclosed area of the material. We demonstrated a design of such living materials and showed both active (eating) and waiting (dormant, hibernation) states with additional recovery for reinitiation of a new active state by observing the metabolic activity over two full nutrition cycles of the living material (active, hibernation, reactivation). This novel class of living materials can be expected to provide nonclassical solutions in consumer goods such as packaging, indoor surfaces, and in biotechnology.

Related Stories

Heart-healthy yak cheese

March 17, 2008

In a finding likely to get cheese lovers talking, researchers in Nepal and Canada report that yak cheese contains higher levels of heart-healthy fats than cheese from dairy cattle, and may be healthier. Their study is scheduled ...

Cheese curd recalled in New York State

December 5, 2007

The U.S. Food and Drug Administration announced the recall Wednesday of Heritage Cheese Ranch Peppercorn Cheese Curd because of a labeling error.

Wonderful cheese is all in the culture

January 6, 2009

It's an age-old tradition that dates back at least 8,000 years but it seems we still have much to learn about the bacteria responsible for turning milk into cheese.

Searching for the ultimate blue cheese

February 3, 2011

It’s the champagne of the cheese world and the gastronomic pride of the East Midlands but now blue cheeses like Stilton are literally under the microscope in a quest for the best possible quality.

Caesar salad dressing is recalled

April 1, 2008

The U.S. Food and Drug Administration announced the recall of America's Choice-brand classic Caesar salad dressing because of a labeling error.

Recommended for you

Bio-renewable process could help 'green' plastic

January 19, 2018

When John Wesley Hyatt patented the first industrial plastic in 1869, his intention was to create an alternative to the elephant tusk ivory used to make piano keys. But this early plastic also sparked a revolution in the ...

Simulations show how atoms behave inside self-healing cement

January 19, 2018

Researchers at Pacific Northwest National Laboratory (PNNL) have developed a self-healing cement that could repair itself in as little as a few hours. Wellbore cement for geothermal applications has a life-span of only 30 ...

Looking to the sun to create hydrogen fuel

January 18, 2018

When Lawrence Livermore scientist Tadashi Ogitsu leased a hydrogen fuel-cell car in 2017, he knew that his daily commute would change forever. There are no greenhouse gases that come out of the tailpipe, just a bit of water ...

A new polymer raises the bar for lithium-sulfur batteries

January 18, 2018

Lithium-sulfur batteries are promising candidates for replacing common lithium-ion batteries in electric vehicles since they are cheaper, weigh less, and can store nearly double the energy for the same mass. However, lithium-sulfur ...

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

not rated yet Jan 09, 2012
What a twist on eating.

Cheese that eats you instead.


Seriously though, self-cleaning solar panels that eat the dust and debris to stay clean.

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.