Deleting a Gene Quells a Pesky Cheese-destroying Fungus

In naturally aged cheeses like brie and some varieties of cheddar, the production of the rind is interfered with by an antibiotic produced by a mold gene, according to research. Using antimicrobial compounds, the mold, a wild Penicillium species, outcompetes the bacterial colonies on the cheese rind. This finding sheds light on how fungi might influence the microbiome of cheese and raises the possibility that using scientific knowledge could aid cheese-making artists in preserving their goods by reducing unwelcome mold disturbances. The study emphasizes the complex interactions between microorganisms during cheese production and how they affect the flavor of the finished product.

The creation of secondary metabolites is regulated by a gene known as laeA, which was found by researchers. They were able to restore normal bacterial development on the cheese rind by developing a mutant fungus deficient in laeA, demonstrating that the disruptive effects of the mold were reduced. According to further research, laeA is required for the production of the psoA gene, which produces the antibiotic-like secondary metabolite known as pseurotin. The scientists showed that the germs continued to grow unhindered after pseurotin was removed. This research sheds light on how mold affects the microbiome of cheese and makes suggestions for potential strategies to prevent mold growth and aid cheese producers in maintaining the quality of their products.

The mold is thought to penetrate the microbial population on the cheese rind through the production of a secondary metabolite called pseurotin. With this discovery, the makeup of a microbiome has for the first time been demonstrated to be mediated by a fungal natural product, highlighting the potent impact of fungal chemicals on the development of diverse species. The work provides insight into a topic that has only recently received a limited amount of attention: how fungus interact with bacterial ecosystems. New avenues for preventing undesired mold infestations in the cheese-making process have been made possible by this research. Cheese manufacturers may be able to stop fungus from taking over and protect the caliber of their goods by detecting those with possible negative impacts on bacterial populations. The relevance of comprehending these fungal-bacterial interactions and their prospective uses in the cheese-making industry are emphasized by the study.

That Stinky Cheese is a Result of Evolutionary Overdrive

Did you know that cheese makers use a particular species of mold to come up with the many cheese flavors we eat today? Have you also thought about the genetic histories of mold and how it adapts to life on cheese curds?

Dr. Robert Rodriquez de la Vega and his scientists reported to the journal Current Biology, that cheese makers have thrown their mold into evolutionary drive. Roquefort was one of the first cheeses made in France in a traditional way. The cheese makers used to take loaves of bread and leave in caves. Inside of them Penicillium roquefort would grow on the walls and eventually attack the bread. Then they would take of pieces of the bread and put them on the curds, so the mold would grow on them. In the early 1900s scientists identified what these species were and made it possible for scientists in the laboratories to select certain strains of mold to produce cheese. Could this mean that mold is a genetically modified organism?

Over centuries, mold has picked up large chunks of DNA from other species in order to adapt on cheese curds. Dr. Rodriquez de la Vega and his colleagues were curious about how mold changed once people started using them to make cheese. They were able to see the similarities of these genes, but also noticed chunks of DNA that did not look similar. The genes that looked different were actually genes that were an identical form of distantly relative species. This kind of swapping is called horizontal gene transfer. Horizontal gene transfer is when one organism takes a piece of DNA from another species and creates it own genome. Dr. Rodriquez de la Vega found out that up to 5 percent of the entire genome of each mold was made up of DNA from another species. So this means that new flavors are able to be made, but also gives mold that contaminate cheese a chance to spread and pick up modified genes.

In opinion, I always wanted to know how the different cheese flavors came about. I am only familiar with the common cheeses like cheddar, provolone, american, and pepper jack. I have never seen cheese that was blue, but had an acquired taste like roqueforti. It is interesting how mold can alter genes and change the either the texture of cheese or even its appearance. I also wonder in what ways can cheesemakers protect their cheese from contamination. Can the modified genes be reversed, so the cheese is no longer contaminated?

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Evolutionary Smile!

While the whole world seek the mysterious life forms in outer space, people failed to realized one of the most intriguing species can be found in our own backyard--slime molds! Yes indeed, these creatures are the linage of amoebas that lived in the soil of Earth for billions of years. Even though their name have the word "mold" in it, they are from the mold that grows in damp areas; they're from a soil amoeba family. While they have been on Earth for quite sometime, they spent their lifetime growing into different forms.

In order to survive, the organism gathered together in groups of thousands to form a single blob. The blob can stretch itself into a form a a slug, allowing it to travel like a worm towards light. When it reach to the surface the cells turn into stiff stalks while others crawl to the top and form a sticky ball of spores. This ball usually get stuck under the foot of animals and travel to different places.

Inside the slug, 1% of the amoebas search for any infectious bacteria. When they find a pathogen, they eat it then detach themselves from the slug, and die from infection to ensure the slug will be in good health. When the slug is ready to make a stalk, more amoebas die to allow others live. They climb onto of one another; transforming their insides into cellulose. 20% of Dictyostelium cells die this way so they the remaining 80% can climb on their corpse and become spores.

Scientists sequence the DNA of these smile mold to figure out how they evolved and found out the two main groups pf smile mold are each other's closest relatives. Dr. Baldulf, a Swedish biologist who is analyzing the DNA of species in the Eumycetozoan Project suggested that these slime molds may be the link to knowing how soil was first developed on land. Traits such as making spores may have first evolved when they came ashore; the ability to form into a slug was later evolved to travel and spread more spores.

I think it's very fascinating something so minuscule can have a connection to the world itself. Comparing to the lifespan of dinosaurs or humans, these slime molds could be as old as the Earth itself. I think it's interesting how the past and the present is connected in ways that people normally overlook. These tiny single-celled organisms work together to ensure the survival of others, I feel we can learn a lot from them, scientifically and about life in general. After all, it's the little things that matter and you'll be surprise what huge surprises they can achieve!  

Article: http://www.nytimes.com/2011/10/04/science/04slime.html?pagewanted=all&_r=1&

Related article: http://www.sciencedaily.com/releases/2014/02/140218143318.htm