Conan The Bacterium – The World’s Most Toughest Bacterium

By Anupum Pant

I have been a big fan of Tardigrades and the Radiotrophic fungi since the day I found out about them. I’m a fan mostly because these are the kind of creatures that can survive in very different (extreme) kind of settings. For instance, Tardigrades can waddle through the vacuüm of space without getting harmed! (more in the links above).

These are Extremophiles – creatures that can survive extreme heat, cold, dehydration, acidity, or radiation. But Extremophiles have their own abilities and specialties. That means, if they are able to survive one kind of harsh condition, say extreme heat, there is a fat chance that the same organism will have the ability to survive other harsh conditions too. That is not the case with the bacteria we see today…

The badass bacteria beats Tardigrades.

A bacteria that goes by the name Deinococcus Radiodurans enters. It is the king of Extremophiles. Or, you can call it a Polyextremophile (reason below). So, to my list of the most badass creatures, I’m happy to announce that I’m adding a new creature – Conan the Bacterium or Deinococcus Radiodurans (DR).
(If you don’t get it, it is a bacteria nicknamed after the badass barbarian warrior movie – Conan the Barbarian – not after the funny guy on TV – Conan.)

This bacterium is so tough that it is listed in the Guinness Book of World Records as “the world’s toughest bacterium”.

What can it survive? Now what makes it better than Tardigrades or any other known creatures out there, is its ability to withstand all of the extreme conditions at the same time – Polyextremophile. So, if you decide to put it through all of these conditions at the same time –

Vacuum + Zero humidity + 85 degrees C temperature + 500,000 rads of radiation

– it will survive. The most amazing part – it will survive all of it easily. To give you an idea how much 500,000 rads of radiation is, human beings would get cooked (or charred) to death within seconds if they get exposed to that amount of radiation! Yet Conan the bacterium takes it all as if it was nothing, and can still go up to 1,500,000 rads. At those levels, even the molecular structure of glass begins to break down!

Habitat: No one knows where this bacterium belongs naturally. It is found anywhere and everywhere. You might find it in elephant’s dung or in the polar areas of the earth where the environment of earth closely resemble that of Mars.

DNA repair with a twist: Like most other bacteria, DR can repair its own DNA after damage due to extreme amounts of radiation. But, even here, it manages to stand out from the masses (other bacteria). Other bacteria like E.Coli can’t survive, more than two or three major DNA breaks. However, DR can keep on bringing its broken DNA to the original state over and over. And every time, it can stitch back its completely blown DNA bits, in a matter of few hours. There is still a lot to learn about how it manages to do this.

However, the mechanism it uses is certainly different and better from the way other bacteria do it. It doesn’t seem to have any DNA repair genes like other bacteria. And yet it is able to make complete repairs in the DNA with the help of a certain protein.

Data storage: In the future, if we ever wish to make extremely robust storage devices, we could probably learn to store data in this bacteria’s DNA. And then we might never lose data even in the case of a nuclear apocalypse.

[Source 1] [Source 2] [Source 3]

Radiotrophic Fungi Feeds on Gamma Radiation

By Anupum Pant

Background

On April 26th 1986 a catastrophic nuclear accident that occurred at the Chernobyl Nuclear Power Plant in Ukraine and is still considered the worst nuclear power plant accident ever (another one happened in Japan recently). The massive explosion spewed out huge amounts of radioactive particles into the air which spread till Europe.

As a result of this tragedy, it was reported that 31 people died within a few months due to acute radiation sickness. In total, more than 200 people were affected. It is estimated that deaths caused due to cancer by Chernobyl may be around 4,000 among the 5 million persons living in the surrounding area.

The disaster was responsible for turning green trees, in the 10 square kilometers of pine forest around the reactor, into red trees. Eventually the trees died and the forest has been called the “Red Forest” ever since.

Today, an area covering 30 km in all directions from the power plant has been labeled as the “zone of alienation“. Mostly it is uninhabited by humans (excluding those 300 odd residents who have decided that they won’t leave). Till date, the radiation levels remain extremely high. Workers who are responsible for rebuilding the place are only allowed to work for a maximum of five hours a day for one month and are asked to take a 15 day rest after that.

With an environment where the radiation level even today is about 500 times higher than the normal environment, it is estimated that the area will remain uninhabitable for humans for the next 20,000 years.

But something lives inside the still-highly-radioactive ruins

Few years back when a robot was sent into the devastated reactor, it returned with samples from the walls of the ruined power plant. These samples contained a black colored substance which piqued the researchers’ interests.

After performing several tests on these samples they concluded that the black samples comprised of two kinds of fungi. Both of them contained a pigment called melanin (the pigment that colors our skins). The fungi had been using melanin to convert radiation into chemical energy. It was mind-boggling for everyone to learn that amidst the toxic sarcophagus a creature was living and was feeding on gamma radiation for making food and to grow. Scientists decided to call it, the “radiotrophic fungi” – the fungi which feeds on gamma radiation.

It is like plants using solar radiation for making food, just that, in this case, the frequency of the electromagnetic radiation being used, is different.

Feeding the spacemen

Scientists say, since the pigment is also present in our skins, and as ionizing radiation is prevalent in outer space, in the future, astronauts could probably rely on melanin as a source of food during long missions or for living on other planets; Just like the radiotrophic fungi does.

According to Dr Casadevall:

While it wouldn’t be enough energy to fuel a run on the beach, maybe it could help you to open an eyelid.

Nuclear Powered Pacemakers for the Heart

By Anupum Pant

Heart and Pacemakers

Your heart is a complex device. It comes with its own sophisticated electrical system that controls the rate and rhythm of your heartbeats. The electrical system is responsible to make the heart contract and as a result pump blood into your body. It is required to keep a proper rate and rhythm. There is a whole lot to learn about how the human heart works. But that is for some other day. Or, you can read it here – [Link]

As years pass, like any other electrical system, even the heart is prone to electrical faults. Faulty signals can make the rhythmic beating, non-rhythmic. This can make life difficult for a person. Enter pacemaker…

Pacemakers are small devices that are placed in the chest. They use low energy pulses to maintain the rate and rhythm of your heartbeats by overcoming the faulty electrical signals. Sometimes Permanent pacemakers have to be used to control long-term heart problems. For this, they are required to run for a long time without replacement. Who’d want their chest dug every two months to replace the pacemaker battery?!

Nuclear powered

Nuclear batteries work due to a nonstop radioactive decay of certain elements. They can last for incredibly long times. Due to their extremely long lives and high densities they are used in space devices and other underwater systems; basically, in systems where replacement of batteries is not an option. So, scientists from the past thought – why not use them to power pacemakers too!

In the 1960s, scientists at the Los Alamos Scientific Laboratory in New Mexico began exploring the feasibility of being able to use nuclear power for pacemakers. The idea was to develop a penny sized battery that could be used with a pacemaker and could be implanted in a human body. It was made. And they decided to call it an atomic battery or Radioisotope battery or simply a nuclear battery.

Despite bearing the name “nuclear” battery, they were not really little nuclear reactors as they didn’t use chain reactions to produce energy. So, there was no danger of a meltdown. They were safe devices. No radiation related issues were ever reported.

The Problem

Agreed these batteries were costly and weighed a lot, but that was not the problem. The big problem was that they contained hazardous material which had to be recovered once a patient died. There were several instances when a person had died; the living relative had returned the nuclear battery, but the Nuclear Regulatory Commission never received it.

However, later in the year 1988 last of the nuclear batteries were used. Now they were being replaced with long lasting (~10 years) lithium batteries.

Even today Los Alamos National Laboratory has a fact sheet on their website that mentions what to do in case you find a nuclear battery.