The Largest Bacteria-Eating Virus!

Feb 18, 2020 By Ritali J, Writer
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Virus that attack bacteriaIn the natural world, there are plants and animals that live off of other plants and animals. 

But viruses are a different story. Did you know that viruses are non-living biological molecules?

The viruses that attack bacteria are known as bacteriophages (phages in short). They can be found in various environments including human saliva, animal feces, freshwater, hospitals, soils, and hot springs.

A team led by researchers at UC Berkeley has recently uncovered new collections of gigantic phages, nearly ten times larger than the phages we know today! Let’s examine the findings of the study.

How Do Phages Survive?

Bacteriophage structureWhen phages attack bacteria, they insert their genetic code into the host’s DNA. This allows them to use the resources inside the cell to clone themselves, and in some cases, even kill the host cell.

Viruses are categorized as nonliving because they need help from host cells to reproduce, and they do not have ribosomal structures. Ribosomes are tiny molecular machines that manufacture proteins through a process known as translation. These proteins and enzymes are important for the cell's functionality. 

However, researchers were surprised to find that some of the gigantic phages had genes that could create simple ribosome structures. This has led scientists to question whether viruses are living or nonliving compounds!

Virus Warfare!

Cutting DNA strandWe know that bacteria have developed a mechanism to fight invading viruses, known as CRISPR. 

When bacteria are attacked by viruses, they capture the genes from invading viruses into CRISPR memory. This information is used by bacteria to cut out unwanted phage DNA from their own DNA -- think of it like molecular scissors! In fact, scientists have been exploring this technology for gene editing in humans.

Researchers were surprised to find that the giant phages were carrying CRISPR genes! Why do viruses need CRISPR? They believe viruses use this mechanism to destroy rival phages -- other viruses that attack the same host cell. They may even be using it to disable the bacteria's defense mechanism! 

Scientists plan to cultivate these giant phages in labs to further explore CRISPR systems and gene editing. 

Sources: Innovative Genomics, Science Alert, Live Science, Nature