The good kind of viruses: When foes become friends

Roughly a year ago, COVID hit us and changed our lives – for the better or worse – but in most cases definitely for the latter. The Corona virus is unarguably one of the viruses we do not want anywhere near us. So we all agree that viruses are a bad, scary thing that we neither want, nor need in our lives, right? But wait! Don’t be so quick to judge, there’s more to it you might not know about viruses.

A short excursion into the world of viruses

Actually, there’s a wide variety of viruses on our planet, and not all of them are bad. Some of them might even be very useful for us humans.

But what exactly are viruses? Oftentimes people mistake viruses for bacteria but amongst many differences there is one very important one telling them apart: bacteria are living organisms, viruses are not. They do not grow, cannot produce energy, and do not consist of cells. A virus can be seen as an infectious android, if you will. Viruses are much smaller than bacteria and – one of the things that make them so scary – they are also immune to antibiotics.

Viruses are not able to reproduce on their own and therefore need a host to replicate by infecting a host cell and inserting their genome (which can be DNA or RNA, depending on the specific virus).

The host cell will be re-programmed to produce copies of the virus instead of performing its initial task. Once the cell is filled with virus copies it will burst and release the clones which then again will infect more cells.

Okay, now that you know a few things about viruses we all can agree: viruses sound scary.

But wait! As we just explained, viruses infect organisms. Bacteria are also organisms. Now let’s put two and two together: viruses can destroy bacteria. Imagine the following scenario: You have bacteria that can hurt the human organism and you have viruses that cannot use human cells as hosts but instead will infect bacterial cells.

This may sound made up but it is actually possible. We can use certain viruses in the fight against bacteria without the risk of getting harmed ourselves.

Bye bye, juice spoilage!

Juices are made out of fruit, as we all know. Depending on the sort of fruit and the part of the world you are located at, you probably noticed that fruit can be very expensive. We all know the reasons for this but let’s just look at them again real quick: not every fruit does grow everywhere so we often need to import it. Also fruit does not grow all year round and therefore is not available all the time, if not bought frozen at the supermarket. This results in the need of importing the food, which is cost-intensive, and bad for our environment since transportation causes a lot of emissions. And there’s even more factors determining the pricing of fruit. Plants sometimes need years to be able to grow a decent amount of fruit. An apple tree for example can take up to 5 years before it can grow any apples. Then, of course, there is also always the risk of bad harvest.

Now let’s get back to the juices. It’s not rare that juice goes bad. Juice spoilage actually causes revenue losses of at least $ 100 Million per year! Therefore the company PepsiCo decided to set up a challenge within the ‘MicroBiome-Push’-project, which is part of the Food Solution program run by the European Institute of Innovation and Technology (EIT), to solve this problem once and for all.

And in fact this story has a happy ending: a group of students from the Israel Institute of Technology (Technion) came up with a solution and won the contest being awarded

100,000 € for their achievement. 
How did they do it? You guessed it: with viruses!

With a little help from my ...viruses

Juice spoilage is caused by a certain kind of bacteria, Alicyclobacillus acidoterrestris (ACB), that can be found in the soil near fruit trees. The tricky thing about those bacteria: they are immune to heat, or cleaning processes and therefore hard to get rid of.

That is when it’s the time to shine for viruses, our little heroes in this scenario. The bright minds of Technion used special viruses, so-called ‘bacteriophages’ that will only use bacteria as hosts.

Now let’s think about the explanation about how viruses reproduce we gave you in the beginning of this article. The viruses will infect the ACB bacteria to replicate and destroy those organisms by doing so. While killing the bacteria the viruses won’t be harmful to organisms drinking the juice since they are bacteriophage and therefore – let’s call a spade a spade – are just not interested in us humans.

As you see, not only are not all viruses bad for us but some of them can even be considered our friends rather than foes.

Isn’t our world full of wonders? Stories like this one truly remind us why we are passionate for science.