If size doesn't matter, a husband-and-wife research team's microscopic study of bacteria-like objects at Mississippi State may shed new light on age-old questions about life on Earth and other planets.
Microbe-hunting university geologists Leo Lynch and Brenda Kirkland are using high-powered electron microscopes to scan miniscule features on a variety of rocks, clay, limestone, and other natural substances in hot pursuit of nanobacteria.
Their separate research projects also may reveal how oil recovery is enhanced and human arterial blockage created by the infinitesimal matter.
The incredibly small spheroidal and ovoid objects are found in rocks and minerals that some scientists believe are tiny fossil evidence of the most primitive and earliest life on Earth and in outer space. Other scientists, however, dispute their link to life.
"Nanobacteria are strange things," said Lynch, a clay mineralogist who studies how the objects grow in oil reservoirs. "We don't really know what they are, but the observation is that there are lots of suspicious-looking features on a whole variety of rocks, minerals, human body parts and meteors that look a lot like very small bacteria."
When he says very small, he means very small. MSU's Electron Microbeam Laboratory, however, houses a $500,000 scanning electron microscope that provides a magnification of 70,000 to 100,000 times the size of the tiny objects. A new kind of SEM being installed can magnify objects up to 300,000 times.
Called nanobes, nanobacteria or nano-organisms, the minute particles borrow their name from a unit of measurement called the nanometer, which is one-billionth of a meter. While the tiniest bacteria measure 200 nanometers in diameter, nanobacteria can range from 20 to 150 nanometers.
The period at the end of a sentence is about one million nanometers in diameter.
"Nanobacteria is a controversial term because these things are too small to be bacteria as we know them," said Kirkland, a carbonate sedimentologist from Dallas,Texas, who studies the formation of microbes in limestone. "But it sure looks like bacteria."
"My wife (Kirkland) and I have been trying to discover what these features really are," added Lynch, a Passaic, N.J., native who joined the MSU faculty in 1999. "Just because something looks like a bacterium doesn't mean it is a bacterium."
The couple's scientific mentor at the University of Texas at Austin, where they first met as research colleagues, was Professor Emeritus Robert L. Folk, dubbed by some as "The Father of Nanobacteria." It was Folk who first discovered the bacteria-like structures in Italian hot-springs deposits in 1987. Nano-sized shapes were linked to outer space when they were found in the Martian meterorite ALH84001 in 1996, and also in the Allende and Murchison meteorites.
"It was actually Folk's early work that inspired NASA scientists to look at the Martian meteorite at super-high magnification, and that led to the whole 'Life on Mars' thing a few years back," said Lynch.
He said a "public whoopdedoo factor" at the time, however, sparked scientific debate on whether shapes measuring 20-200 nanometers in diameter on the 4.5-billion-year-old meteorite should be considered fossils of Martian microbes; or are too small to be considered life, as contended by many leading biologists.
A panel of 18 experts convened by the National Research Council of the National Academy of Sciences determined in 1998 that 200 nanometers probably represents the lowest size unit that should be considered "life" as we know it. The panel also said, however, that primitive microbes once could have been as small as 50 nanometers.
While scholars debate nanobacteria's significance to the origin of life, Lynch and Kirkland are proceeding with their own respective, illuminating research projects--his exploring bacteria growth in oil reservoirs; hers examining nanobacteria as a factor in human arterial blockage and other diseases. Lynch is an assistant professor and Kirkland an adjunct professor in the department of geosciences.
Lynch, a softrock geologist who received his doctorate from U.T.-Austin in 1994, has been working with another MSU faculty member, microbiologist Lewis Brown, on a nearly completed project. They are working to determine how regular bacteria might help extract more oil from oil reservoirs by affecting the flow of water.
"A side thing is looking at all the little nanobacteria that are down there too," Lynch said, noting the U.S. Department of Energy and oil companies are supporting the project. "How can we use the bugs down there to get more oil out?"
While Lynch delves beneath the surface of the earth, Kirkland, who earned a doctorate in geology from Louisiana State University in 1992, probes the human body.
"I think we're just opening doors," said Kirkland. "My hope is that my research will give people something else to look for when they work on arterial calcification. A recent study showed a relationship between infection and heart disease. Maybe this (the nanobacteria) is the infection. I don't know, I'm not a medical researcher, but it gives them something else to look for at a higher magnification."
According to scientific journals, nanobacterium sanguineum has been implicated by many nanobacterial researchers to be the cause of calcification in various human pathological states--including cardiovascular disease, coronary artery calcification, cataracts, calcification of cancer tissue, arthritic spurring and polycystic kidney disease. The Mayo Clinic and University of Texas published an abstract less than two years ago describing their successful repetition of a European experiment that found nanobacteria in blood. Scientists still are discussing the DNA characteristics of the bacteria-like entities, along with cause and effect.
"You're not supposed to have bacteria in your blood, but some people do," explained Kirkland, the mother of two small daughters. "We managed to look at the calcified portions of arteries and found the calcification was composed of these same little balls or nanospheres.
"I wanted to see what was in the arteries," she continued. "I wanted to see if we could find something that no one had seen before. Indeed, we did find a lot of things that people hadn't seen before. We found elongated bacteria that had not been seen before in a heart valve. The doctors were surprised. They knew the valve was diseased, but they hadn't actually seen the pathogen."
For more information on nanobacteria or to link to a photo gallery, visit http://www.msstate.edu/dept/geosciences/4site/nannobacteria.htm.