This has been demonstrated by research carried out at TU Delft's Kavli Institute of Nanoscience. The results will be appearing this week in the online edition of the prestigious scientific journal Proceedings of the National Academy of Sciences (PNAS) and as the cover article in the September 1 print issue of PNAS.
Using nanofabrication, Delft scientists made minuscule channels, measuring a micrometer or less in width and 50 micrometer in length, on a silicon chip between tiny chambers containing bacteria. Subsequently they studied the behaviour of Escherichia. coli and Bacillus. subtilis bacteria in this artificial environment. The bacteria were genetically modified so that they were fluorescent and could easily be followed using a special microscope.
Under normal circumstances these bacteria swim and this research showed that they retain this motility in surprisingly narrow channels. They swam just as actively as usual even in channels that were only 30 percent wider than their own diameter (of about 1 micrometer). In even narrower submicron channels the bacteria stopped swimming, and an unexpected effect took place: The bacteria were able to make their way through ultra-narrow passageways in another manner, that is by growing and dividing. The researchers found that this way, E. coli bacteria could squeeze through narrow slits that were only half their own diameter in width. Post-doctoral researcher, Jaan Männik: "This took us totally by surprise. The bacteria become completely flattened. They have all sorts of peculiar shapes both in the channels and when they finally come out at the other side. What is really remarkable, however, is that in the channels, and therefore under extreme confinement, they continue to grow and divide at normal speeds. Apparently their shape is not a determining factor for these activities."
Subterranean bacteria, membrane filters and pacemakers
The flat bacteria form a new phenotype,. According to the researchers, this form may be more common than one might think. The bulk of the biomass on Earth is to be found under the ground. Here, bacteria often live in spaces that measure around a micrometer. The study suggests that many more bacteria may be present in small spaces than was always thought. This may have direct consequences, for example for membrane filters (with tiny pores) for water treatment and for medical applications, such as pacemakers or other implants, where bacteria must be excluded as much as possible. The results of the study also provide more fundamental understanding of the behaviour of bacteria that are 'locked up' in nanosized environments.
Little is known about the effect of this sort of confinement on the behaviour of bacteria as yet. According to Prof. Cees Dekker, this has to do with the required combination of very different disciplines: "Microbiologists do not generally engage in nanofabrication, which enables us to examine this area under controlled conditions, and nanoscientists usually know little about the behaviour of bacteria. My colleague, Juan Keymer, an evolutionary biologist, and I are now trying to combine these disciplines in our new Department of Bionanoscience. And this is leading to all sorts of new discoveries."
The research results will be appearing in the week beginning 17 August in the online edition of the scientific journal, Proceedings of the National Academy of Sciences (USA). The article will also be featured as the cover article in the print version of PNAS to be published on 1 September 2009.
Prof. Cees Dekker | EurekAlert!
Unique genome architectures after fertilisation in single-cell embryos
30.03.2017 | IMBA - Institut für Molekulare Biotechnologie der Österreichischen Akademie der Wissenschaften GmbH
Transport of molecular motors into cilia
28.03.2017 | Aarhus University
The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.
To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
30.03.2017 | Health and Medicine
30.03.2017 | Health and Medicine
30.03.2017 | Medical Engineering