Hydrothermal vents: Hot spots of microbial diversityOctober 05, 2007New analysis aids in discovery of thousands of deep-sea microbes MBL, WOODS HOLE, MA-Thousands of new kinds of marine microbes have been discovered at two deep-sea hydrothermal vents off the Oregon coast by scientists at the MBL (Marine Biological Laboratory) and University of Washington's Joint Institute for the Study of Atmosphere and Ocean. Their findings, published in the October 5 issue of the journal Science, are the result of the most comprehensive, comparative study to date of deep-sea microbial communities that are responsible for cycling carbon, nitrogen, and sulfur to help keep Earth habitable. Using a new analytical technique called "454 tag sequencing," the scientists surveyed one million DNA sequences of bacteria and archaea, two of the three major domains of life. The DNA was taken from samples collected from two hydrothermal vents on the Pacific deep-sea volcano, Axial Seamount.
The researchers discovered that while there may be as few as 3,000 different kinds of archaea at these sites, the bacteria exceed 37,000 different kinds. "Most of these bacteria had never been reported before, and hundreds were so different from known microbes that we could only identify them to the level of phylum," says lead author, Julie Huber of the MBL. "Clearly, additional sampling of these communities will be necessary to determine the true diversity." The research also revealed that the microbial population structures differed between vent sites due to their different geochemical environments. The ability to link environmental characteristics with microbial population structures using 454 tag sequencing allows scientists to assess how natural and manmade environmental changes are affecting diverse habitats on Earth. Until now, microbiologists have had limited tools for assessing microbial populations and diversity. The MBL's 454 tag sequencing strategy is an important contribution to the young science of metagenomics, which seeks to characterize communities of organisms through genomic analysis. While other metagenomic studies look at all the genes in an environmental sample, such as a bucket of seawater or scoop of sediment, 454 tag sequencing examines one tiny, highly variable region of one gene that all microbes have (the 16s rRNA gene). It is much more efficient and cost effective than other environmental microbial survey tools. "The tremendous diversity we found using 454 tag sequencing suggests that even the largest metagenomic surveys--which capture only the most highly abundant taxa-- inadequately represent the full extent of microbial diversity," says MBL scientist David Mark Welch, one of Huber's co-authors. "Even with tag sequencing, statistical tests of our data suggest we still only sampled about half of the total number of species that were actually present." The new findings also underscore just how daunting understanding marine microbial diversity is. "This research demonstrates that surveys of hundreds of thousands of sequences will be necessary to capture the vast diversity of microbial communities, and that different patterns in evenness for both high and low-abundance taxa may be important in defining microbial ecosystem dynamics," says Mitchell Sogin, director of the MBL's Josephine Bay Paul Center for Comparative Molecular Biology and Evolution. This research is part of the ongoing International Census of Marine Microbes, a massive effort to inventory the world's marine microbial diversity. It is also part of a major MBL initiative to study microbial ecology and evolution to understand how microbial communities are evolving in response to natural and human-induced environmental changes. Marine Biological Laboratory Science News and Science Current Events Tag Cloud This tag cloud is a visual representation of term frequencies of random science news topics with common terms grouped together and emphasized by their display size. Abdominal Fat Pulmonary Embolism Hubble Space Telescope Viral Infection Maize Pulsar Angiography Tumor cell Microscopy Ear Infections Narcolepsy Video Games Blood Vessel Digital Camera Anthrax Cancer Patient Preterm Birth Copd Cancer Therapy Nanoparticle Rice Birth Weight Chromatin Concussion Stem Cell Transplant
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Related Hydrothermal Vents Current Events and Hydrothermal Vents News Articles Asteroid attack 3.9 billion years ago may have enhanced early life on Earth, says CU-Boulder study The bombardment of Earth nearly 4 billion years ago by asteroids as large as Kansas would not have had the firepower to extinguish potential early life on the planet and may even have given it a boost, says a new University of Colorado at Boulder study. Marine scientists return from expedition to erupting undersea volcano Scientists who have just returned from an expedition to an erupting undersea volcano near the Island of Guam report that the volcano appears to be continuously active, has grown considerably in size during the past three years, and its activity supports a unique biological community thriving despite the eruptions. Deep-sea rocks point to early oxygen on Earth Red jasper cored from layers 3.46 billion years old suggests that not only did the oceans contain abundant oxygen then, but that the atmosphere was as oxygen rich as it is today, according to geologists. Earth's highest known microbial systems fueled by volcanic gases Gases rising from deep within the Earth are fueling the world's highest-known microbial ecosystems, which have been detected near the rim of the 19,850-foot-high Socompa volcano in the Andes by a University of Colorado at Boulder research team. Great Lake's sinkholes host exotic ecosystems Researchers are exploring extreme conditions for life in a place not known for extremes. As little as 20 meters (66 feet) below the surface of Lake Huron, the third largest of North America's Great Lakes, peculiar geological formations-sinkholes made by water dissolving parts of an ancient underlying seabed-harbor bizarre ecosystems where the fish typical of the huge freshwater lake are rarely to be seen. Genetic adaptations key to microbe's survival in challenging environment The genome of a marine bacterium living 2,500 meters below the ocean's surface is providing clues to how life adapts in extreme thermal and chemical gradients, according to an article published Feb. 6 in the journal PLoS Genetics, an open-access publication published by the Public Library of Science. No joy in discoveries of new mammal species -- only a warning for humanity, Paul Ehrlich says In the era of global warming, when many scientists say we are experiencing a human-caused mass extinction to rival the one that killed off the dinosaurs, one might think that the discovery of a host of new species would be cause for joy. News Release : Carbon Acts Like Rustoleum Around Hydrothermal Vents The cycling of iron throughout the oceans has been an area of intense research for the last two decades. Oceanographers have spent a lot of time studying what has been affectionately labeled the Geritol effect ever since discovering that the lack of iron is a reason why phytoplankton grow lackadaisically in some of the most nutrient-rich surface waters. A Zen discovery: Unrusted iron in ocean Iron dust, the gold of the oceans and rarest nutrient for most marine life, can be washed down by rivers or blown out to sea or - a surprising new study finds - float up from the sea floor. U of Minnesota-led study reveals mysteries of deep-sea nutrients Iron dust, the rare but necessary nutrient for most life, can not only be washed into the ocean from rivers or blown out to sea, but it can bubble up from the depths of the ocean floor, a new study led by a University of Minnesota scientist shows. More Hydrothermal Vents Current Events and Hydrothermal Vents News Articles |
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