Ancient bacteria grow giant magnets

Scientists have found that ancient microbes grew huge (by the standards of microworld) magnet, reports Nature News. The work of scientists published in the journal Proceedings of the National Academy of Sciences.

Many bacteria (modern and extinct) contain the particles of magnetite - a mineral composed of iron oxide and are magnetic. According to modern view, organisms use these particles as an internal compass. The maximum size of these crystals does not exceed 0.5 micrometers.

Exploring the samples collected from wells in New Jersey, the scientists found magnetite crystals "huge amount" - some of them reached four micrometers in length (millions of shares meters). Age discovered magnets was 55 million years. Spectral analysis of the different isotopes of oxygen allowed the researchers to conclude that the magnetite crystals have a marine origin.

In addition to an unusual size and shape of crystals - it reminds spearhead. According to scientists, the ancient microorganisms can use these crystals, not only for guidance, but it may take to protect. Similar protection mechanism is present in some modern organisms: a form of snails, inhabiting the vicinity of smokers in the bottom of the Indian Ocean, grow their stem thorns of iron sulfide.

Scientists argue that none of the currently known microorganisms do not grow the size of such magnets. Researchers believe that "love" bacteria to magnetite could be the result of high temperatures on the planet at the time. In the climatic history of Earth time period of about 55 million years ago known as Pozdnepaleotsenovy thermal maximum. In the short term ( "only" 100 thousand years) during the sharp global warming, the average temperature on Earth has risen by more than six degrees. More mechanism to explain the relationship between temperature and "love" to magnetite, scientists are hampered.