How to thrive in battery acid and among toxic metals

How to thrive in battery acid and among toxic metals
This is a rock in an Icelandic hot spring near Reykjavik with sulfur and Galdieria sulphuraria. Credit: Christine Oesterhelt

In the movie Alien, the title character is an extraterrestrial creature that can survive brutal heat and resist the effects of toxins.

In real life, organisms with similar traits exist, such as the "extremophile" red alga Galdieria sulphuraria.

In hot springs in Yellowstone National Park, Galdieria uses energy from the sun to produce sugars through photosynthesis.

In the darkness of old mineshafts in drainage as caustic as battery acid, it feeds on bacteria and survives high concentrations of arsenic and .

How has a one-celled alga acquired such flexibility and resilience?

To answer this question, an international research team led by Gerald Schoenknecht of Oklahoma State University and Andreas Weber and Martin Lercher of Heinrich-Heine-Universitat (Heinrich-Heine University) in Dusseldorf, Germany, decoded genetic information in Galdieria.

They are three of 18 co-authors of a paper on the findings published in this week's issue of the journal Science.

The scientists made an unexpected discovery: Galdieria's genome shows clear signs of borrowing genes from its neighbors.

Many genes that contribute to Galdieria's adaptations were not inherited from its ancestor , but were acquired from bacteria or archaebacteria.

How to thrive in battery acid and among toxic metals
This is a volcanic area near Reykjavik, Iceland, where Galdieria sulphuraria has been found. Credit: Christine Oesterhelt

This "" is typical for the evolution of bacteria, researchers say.

However, Galdieria is the first known organism with a nucleus (called a eukaryote) that has adapted to based on horizontal gene transfer.

"The age of comparative began only slightly more than a decade ago, and revealed a new mechanism of evolution—horizontal gene transfer—that would not have been discovered any other way," says Matt Kane, program director in the National Science Foundation's (NSF) Division of , which funded the research.

Galdieria's seems to come from genes that exist in hundreds of copies in its genome, all descending from a single gene the alga copied millions of years ago from an archaebacterium.

How to thrive in battery acid and among toxic metals
These are yellow sulfur deposits and Galdieria on a rock near Reykjavik. Credit: Christine Oesterhelt

"The results give us new insights into evolution," Schoenknecht says. "Before this, there was not much indication that eukaryotes acquire genes from bacteria."

The alga owes its ability to survive the toxic effects of such elements as mercury and arsenic to transport proteins and enzymes that originated in genes it swiped from bacteria.

It also copied genes offering tolerance to high salt concentrations, and an ability to make use of a wide variety of food sources. The genes were copied from bacteria that live in the same extreme environment as Galdieria.

"Why reinvent the wheel if you can copy it from your neighbor?" asks Lercher.

"It's usually assumed that organisms with a nucleus cannot copy genes from different species—that's why eukaryotes depend on sex to recombine their genomes.

"How has Galdieria managed to overcome this limitation? It's an exciting question."

What Galdieria did is "a dream come true for biotechnology," says Weber.

"Galdieria has acquired with interesting properties from different organisms, integrated them into a functional network and developed unique properties and adaptations."

In the future, genetic engineering may allow other algae to make use of the proteins that offer stress tolerance to Galdieria.

Such a development would be relevant to biofuel production, says Schoenknecht, as oil-producing algae don't yet have the ability to withstand the same extreme conditions as Galdieria.

Explore further

New study sheds light on reasons behind genomes differences between species

More information: "Gene Transfer from Bacteria and Archaea Facilitated Evolution of an Extremophilic Eukaryote," by G. Schönknecht, Science, 2013.
Journal information: Science

Citation: How to thrive in battery acid and among toxic metals (2013, March 7) retrieved 21 August 2019 from
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Mar 07, 2013
That's so not true about the creature from the Alien movie, nowhere is that implied.

Harumph harumph

Mar 08, 2013
That's so not true about the creature from the Alien movie, nowhere is that implied.

Harumph harumph

Well, the creature in the alien movie had acid blood that was like 1000 times more acidic than anything realistically could be, and it could survive in vacuum and in the ion thrust of a ship's main engines, and it could survive several seconds in molten metal. In fact, the cooling of the metal causing shattering is what killed the one in the third movie, not the heat.

Anyway, the organism this article is talking about actually has far more in common with StarCraft's "Zerg" than the Ridley Scott Alien, as the Zerg directly absorb the DNA of other life forms, although they also consciously evolve themselves in several ways.

Anyway, it's more like the Zerg.

Keep it AWAY from contact with MRSA or any STDs, PLEASE...

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