The finding, published in Proceedings of the National Academy of Sciences, profiles the SR1 bacteria, a group of microbes present in many environments, ranging from the mouth to deep within the Earth, that have never been cultivated in the laboratory. Human oral SR1 bacteria are elevated in periodontitis, a disease marked by inflammation and infection of the ligaments and bones that support the teeth.
Scientists also found that the SR1 bacteria employ a unique genetic code in which the codon UGA - a sequence of nucleotides guiding protein synthesis -- appears not to serve its normal role as a stop code. In fact, scientists found that UGA serves to introduce a glycine amino acid instead.
"This is like discovering that in a language you know well there is a dialect in which the word stop means go," said co-author Mircea Podar of the Department of Energy lab's Biosciences Division. Podar and Dieter Söll of Yale University led the team that also included scientists from DOE's Joint Genome Institute who contributed to the analysis of the single-cell sequencing data.
The researchers believe the altered genetic code limits the exchange of genes between SR1 and other bacteria because they use a different genetic alphabet.
"In the big pool of bacteria, genes can be exchanged between species and can contribute to increased antibiotic resistance or better adaptation to living in humans," Podar said. "Because SR1 has a change in its genetic alphabet, its genes will not function in other microbes."
Podar and colleagues envision this work providing a path toward a better understanding of microbiological factors of periodontitis as well as to the establishment of a framework to help scientists interpret genomic data from this bacterium and others that have the same altered genetic code.
"So far, no one has been able to isolate and cultivate this type of bacterium," said Podar, who noted that there are bugs in our mouth that we have no clue about and, until now, this was one of them. "The genetic information obtained by sequencing one single cell may offer researchers a key to 'domesticating' these organisms and studying them in the laboratory."
The work at ORNL was funded by a $1.2 million National Institutes of Health grant to study human microbes and develop approaches to sequence the genomes of species that have not been cultivated. Other authors are James and Alisha Campbell of ORNL, Patrick O'Donoghue of Yale University, and Patrick Schwientek, Alexander Sczyrba and Tanja Woyke of DOE's Joint Genome Institute (http://www.jgi.doe.gov) in Walnut Creek, Calif.
UT-Battelle manages ORNL for DOE's Office of Science. The Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time. For more information, please visit http://science.energy.gov/.
Ron Walli | EurekAlert!
Usher syndrome: Gene therapy restores hearing and balance
25.09.2017 | Institut Pasteur
MRI contrast agent locates and distinguishes aggressive from slow-growing breast cancer
25.09.2017 | Case Western Reserve University
Controlling electronic current is essential to modern electronics, as data and signals are transferred by streams of electrons which are controlled at high speed. Demands on transmission speeds are also increasing as technology develops. Scientists from the Chair of Laser Physics and the Chair of Applied Physics at Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) have succeeded in switching on a current with a desired direction in graphene using a single laser pulse within a femtosecond ¬¬ – a femtosecond corresponds to the millionth part of a billionth of a second. This is more than a thousand times faster compared to the most efficient transistors today.
Graphene is up to the job
At the productronica trade fair in Munich this November, the Fraunhofer Institute for Laser Technology ILT will be presenting Laser-Based Tape-Automated Bonding, LaserTAB for short. The experts from Aachen will be demonstrating how new battery cells and power electronics can be micro-welded more efficiently and precisely than ever before thanks to new optics and robot support.
Fraunhofer ILT from Aachen relies on a clever combination of robotics and a laser scanner with new optics as well as process monitoring, which it has developed...
Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.
A warming planet
Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.
The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...
Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...
19.09.2017 | Event News
12.09.2017 | Event News
06.09.2017 | Event News
26.09.2017 | Life Sciences
26.09.2017 | Physics and Astronomy
26.09.2017 | Information Technology