Four complete new kingdoms of life have been discovered by American researchers in the high alpine environment of Colorado, rewriting the textbooks on microbes.

The new microbe kingdoms were found in barren, boulder-filled tundra slopes west of Boulder, Colorado, delegates of the a meeting of the American Society for Microbiology in Washington DC heard this week.

Dr Allen Meyer, a medical practioner working with Professor Steven Schmidt in the environmental, population and organismic biology department of the University of Colorado in Boulder, made the discovery as part of the U.S. National Science Foundation's 'Microbial Observatories' program.

"It is very interesting and kind of surprising to discover four kingdoms in the same locality," Dr Don Colgan, an evolutionary biologist at the Australian Museum in Sydney, commented to ABC Science Online.

Until relatively recently, 'kingdom' was the highest level of classification in the scientific taxonomic system that places all forms of life into hierarchical categories. Kingdoms are made up of divisions (or phyla), which themselves break down again into classes, then orders, families, genus and finally, species.

Scientists in the 18th century originally classified the kingdoms of life into two basic groups: plants and animals. In 1977, Dr Carl Woese turned biology on its head when he discovered the 'third kingdom of life': archaea micro-organisms that live near volcanic vents on the seafloor without oxygen and in conditions thought to be reminiscent of Earth's earliest environment. He has since proposed that these three kingdoms be placed in a higher classification, called domains.

Two advances in science have helped uncover even more new kingdoms of life, Colgan said: the increase in the analytical power of computers and the discovery of the polymerase chain reaction (PCR) process, which has allowed scientists to look at DNA sequences in intricate detail. A debt must also be paid to adventurers who go to extreme places and collect samples, he added.

Scientists now believe there are many more kingdoms, including fungi and a number of types of single-celled organisms. The number of kingdoms was estimated to be about 30 before the University of Colorado discovery.

The region sits at altitudes of 3,355 to 3,956 metres in elevation, and is subject to nine months of snow and three months of intense sunlight and wind. "It is a relatively plain location compared to core drilling of the mantle or Antarctic environments," Colgan commented. Most of the newer kingdoms have been found in extreme environments.

Meyer and Schmidt used a novel molecular technique that extracts DNA from the soil to identify the organisms living there. "The discovery of new kingdoms means more undiscovered species exist," said Meyer. The researchers concentrated their research on eukaryotic microbes – microscopic organisms that have a membrane around their DNA. The number of microbe species has been growing as scientists use new DNA techniques to uncover the family of eukaryotes.

Instead of culturing organisms, Meyer and Schmidt extracted DNA directly from the soil, obtaining DNA from all the soil organisms at once. Comparing their gene sequencing results with those of known eukaryote organisms allowed them to discover the sequences from the four new kingdoms.

Although they have the sequences of four previously unknown kingdoms, they have not yet identified the specific organisms themselves. They intend to attempt to isolate the microbes in the alpine soil so they can study them.

Unearthing new organisms might help in solving practical problems in agriculture and ecology, Meyer said in a statement. "Newly discovered microbial eukaryotes could be of benefit in understanding soil diversity that may be important in predicting impacts of global change, for example."

"Another important issue is that our alpine regions are changing rapidly," Schmidt added. "Depending on the pattern of decreasing snow cover over the past several years, we are racing to identify the species before bigger changes occur and some of the species disappear before they can be identified."

Source of the given news and the copyrights belong to a ABC Online News

Back