Microbes found in these low life sustaining environments could elucidate origins of life on Earth
LA JOLLA, Calif., Sept. 3, 2013 /PRNewswire-USNewswire/ -- Scientists from the J. Craig Venter Institute (JCVI), a not-for-profit genomic research organization, along with collaborators from the University of Southern California (USC) and Delft University in the Netherlands, have published results from a three year study outlining the microbial diversity in The Cedars, a high pH, ultra reducing, low salinity system of springs located in Northern California. The research, led by first author and post doctoral fellow at JCVI, Shino Suzuki Ishii, Ph.D. has been published in the online, early edition of the journal, PNAS.
This unique spring system is an active terrestrial serpentinization site. Serpentinization is a process whereby water reacts with certain types of minerals in the ground to produce other kinds of minerals, as well as hydrogen, methane and highly alkaline fluids. These sites are common in the deep ocean where tectonic plates meet, but are very rare elsewhere.
For three years the JCVI, USC and Delft University team took multiple samples in three springs at The Cedars and isolated the microbes using sequencing technologies as opposed to culturing them. Each spring was fed by unique groundwater, one by deep groundwater only and the other two by a mixture of deep and shallow groundwater. The team found that the microbial communities remained constant in each spring but that each one had unique microbes which were determined by the type of groundwater by which they were fed.
The microbes in the deep groundwater fed spring were distinct from any other microbial communities found in other terrestrial serpentinizing sites. The most abundant of these microbes are members of the Chloroflexi, Clostridia, and candidate division OD1, followed by some Euryarchaeota. The microbes found in the mixture of shallow and deep groundwater fed sites appear to be similar to other microbial communities isolated from other terrestrial sites. The most abundant of these microbes were Betaproteobacteria.
The team concludes that because of the pristine yet harsh nature of The Cedars environment, the microbes found there could be crucial to understanding the origins of life on Earth and in understanding the key survival mechanism used by these hearty microbes.
Kenneth Nealson, Ph.D., senior author, JCVI Distinguished Professor, Department of Microbial and Environmental Genomics; and Wrigley Chair in Environmental Studies and Professor of Earth Sciences and Biological Sciences at USC, stated, "This combination of water chemistries in The Cedars springs is very challenging for life. While there is plenty to 'eat' (i.e., electron donors) in the form of hydrogen and methane produced by serpentinization there, there is nothing obvious to 'breathe' (i.e., electron acceptors). There are also low levels of sodium to be used for establishing a membrane potential. However, the challenge of sustaining life has been met, as evidenced in this study, by the stable microbial populations seen in each spring. We believe these communities have the potential to yield important insights into survival mechanisms in these challenging, early-earth analog environments."
About J. Craig Venter Institute
The JCVI is a not-for-profit research institute in Rockville, MD and San Diego, CA dedicated to the advancement of the science of genomics; the understanding of its implications for society; and communication of those results to the scientific community, the public, and policymakers. Founded by J. Craig Venter, Ph.D., the JCVI is home to approximately 250 scientists and staff with expertise in human and evolutionary biology, genetics, bioinformatics/informatics, information technology, high-throughput DNA sequencing, genomic and environmental policy research, and public education in science and science policy. The legacy organizations of the JCVI are: The Institute for Genomic Research (TIGR), The Center for the Advancement of Genomics (TCAG), the Institute for Biological Energy Alternatives (IBEA), the Joint Technology Center (JTC), and the J. Craig Venter Science Foundation. The JCVI is a 501 (c)(3) organization. For additional information, please visit http://www.JCVI.org.
SOURCE J. Craig Venter Institute