The scientists found they had to apply a force of about 1 micronewton to remove a single Caulobacter crescentus from a glass pipette. Because C. crescentus is so small, the pulling force of 1 micronewton generates a huge stress of 70 newtons per square millimeter. That stress, which the bacterial adhesions could sometimes withstand, is equivalent to five tons per square inch -- three or four cars balanced atop a quarter. By contrast, commercial "super" glue breaks when a shear force of 18 to 28 newtons per square millimeter is applied.
Caulobacter crescentus affixes itself to solid objects with its stalk and holdfast. Here, two sessile "stalk" cells (bottom) spawn mobile "swarmer" clones of themselves (top).
Hypothetically, C. crescentus’s glue could be mass produced and used to coat surfaces for medical and engineering purposes.
"There are obvious applications since this adhesive works on wet surfaces," said IU Bloomington bacteriologist Yves Brun, who co-led the study with Brown University physicist Jay Tang. "One possibility would be as a biodegradable surgical adhesive."
C. crescentus affixes itself to rocks and the insides of water pipes via a long, slender stalk. At the end of the stalk is a holdfast dotted with polysaccharides (chains of sugar molecules). The scientists show in the PNAS paper that these sugars are the source of C. crescentus’s tenacity. It is presumed these sugars are attached to holdfast proteins, but this has not yet been confirmed. One thing is certain -- the polysaccharides are sticky.
"The challenge will be to produce large quantities of this glue without it sticking to everything that is used to produce it," Brun said. "Using special mutants, we can isolate the glue on glass surfaces. We tried washing the glue off. It didn’t work."
The scientists allowed C. crescentus to attach itself to the side of a thin, flexible glass pipette. They used a micromanipulator to trap the cell portion of the bacterium and pull it directly away from the pipette, measuring the force of strain. In 14 trials, the scientists found they had to apply a force of 0.11 to 2.26 micronewtons per cell before the bacterium detached.
C. crescentus has evolved an ability to live in extremely nutrient-poor conditions, which explains its existence as a common fixture in tap water. Because it exists in tap water at low concentrations and produces no human toxins, C. crescentus poses no threat to human health.
Engineer L. Ben Freund wrote the model used to perform complex mathematical analyses of experimental forces. Peter Tsang and Guanglai Li of Brown University performed experiments and analyzed data. The research was funded by grants from the National Science Foundation and the National Institute of General Medical Sciences (National Institutes of Health).
David Bricker | EurekAlert!
Scientists uncover the role of a protein in production & survival of myelin-forming cells
19.07.2018 | Advanced Science Research Center, GC/CUNY
NYSCF researchers develop novel bioengineering technique for personalized bone grafts
18.07.2018 | New York Stem Cell Foundation
A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.
The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
20.07.2018 | Materials Sciences
20.07.2018 | Physics and Astronomy
20.07.2018 | Materials Sciences