AUSTIN, Texas — Scientists studying how microbes evolve have long assumed that nearly all new genetic mutations get passed down at a predictable pace and usually without either helping or hurting the microbe in adapting to its environment. In a new study published in the journal Nature, an international team of researchers studying tens of thousands of generations of E. coli bacteria report that most new genetic mutations that were passed down were actually beneficial and occurred at much more variable rates than previously thought. The finding could have implications for treating bacterial infections. (more…)
Tag Archives: e coli
Joint BioEnergy Institute Researchers Combine Systems Biology with Genetic Engineering to Improve Production of Isopentenol in E.Coli
In the on-going effort to develop advanced biofuels as a clean, green and sustainable source of liquid transportation fuels, researchers at the U.S. Department of Energy (DOE)’s Joint BioEnergy Institute (JBEI) have identified microbial genes that can improve both the tolerance and the production of biogasoline in engineered strains of Escherichia coli. (more…)
Biologists have worked with the lambda virus as a model system for more than 50 years but they’ve never had an overarching picture of the molecular machines that allow it to insert or remove DNA from the cells that it infects. Now they can, thanks to an advance that highlights the intriguingly intricate way the virus accomplishes its genetic manipulations.
PROVIDENCE, R.I. [Brown University] — For half a century biologists have studied the way that the lambda virus parks DNA in the chromosome of a host E. coli bacterium and later extracts it as a model reaction of genetic recombination. But for all that time, they could never produce an overall depiction of the protein-DNA machines that carry out the work. In a pair of back-to-back papers in the Proceedings of the National Academy of Sciences, scientists produce those long-sought renderings and describe how they figured out what they should look like. (more…)
How’s this for innovative: A Berkeley Lab-led team hopes to engineer a new enzyme that efficiently converts methane to liquid transportation fuel.
“There’s a lot of methane available, and we want to develop a new way to harness it as an energy source for vehicles,” says Christer Jansson, a biochemist in Berkeley Lab’s Earth Sciences Division who heads the effort. (more…)
The first dynamic regulatory system that prevents the build-up of toxic metabolites in engineered microbes has been reported by a team of researchers with the U.S. Department of Energy (DOE)’s Joint BioEnergy Institute (JBEI). The JBEI researchers used their system to double the production in Escherichia coli (E. coli) of amorphadiene, a precursor to the premier antimalarial drug artemisinin.
Using genome-wide transcriptional analysis, the JBEI researchers identified native regions of DNA – called “promoters” – in E. coli that respond to toxic metabolites by promoting the expression of protective genes. They then developed a system based on these promoters for regulating artificial metabolic pathways engineered into the E.coli to enable the bacterium to produce amorphadiene. (more…)
Berkeley Lab scientists image cell-to-cell connections between soil microbes
The next time your Facebook stream is filled with cat videos, think about Myxococcus xanthus.The single-cell soil bacterium also uses a social network. But forget silly distractions. M. xanthus relies on its connections to avoid getting eaten and to score its next meal.
That’s the latest insight from a team of Berkeley Lab scientists. Using several imaging techniques, they saw for the first time that M. xanthus cells are connected by a network of chain-like membranes. (more…)
Berkeley Lab scientists discover the balance that allows electricity to flow between cells and electronics
Just like electronics, living cells use electrons for energy and information transfer. Despite electrons being a common “language” of the living and electronic worlds, living cells cannot speak to our largely technological realm. Cell membranes are largely to blame for this inability to plug cells into our computers: they form a greasy barrier that tightly controls charge balance in a cell. Thus, giving a cell the ability to communicate directly with an electrode would lead to enormous opportunities in the development of new energy conversion techniques, fuel production, biological reporters, or new forms of bioelectronic systems. (more…)
Species facing widespread and rapid environmental changes can sometimes evolve quickly enough to dodge the extinction bullet. Populations of disease-causing bacteria evolve, for example, as doctors flood their “environment,” the human body, with antibiotics. Insects, animals and plants can make evolutionary adaptations in response to pesticides, heavy metals and overfishing.
Previous studies have shown that the more gradual the change, the better the chances for “evolutionary rescue” – the process of mutations occurring fast enough to allow a population to avoid extinction in changing environments. One obvious reason is that more individuals remain alive when change is gradual or moderate, meaning there are more opportunities for a winning mutation to emerge. (more…)