Mineral coatings on sand particles actually encourage microbial activity in the rapid sand filters that are used to treat groundwater for drinking, according to a paper published ahead of print in Applied and Environmental Microbiology. These findings resoundingly refute, for the first time, the conventional wisdom that the mineral deposits interfere with microbial colonization of the sand particles.
"We find an overwhelmingly positive effect of mineral deposits on microbial activity and density," says corresponding author Barth F. Smets, of the Technical University of Denmark, Lyngby.
Mineral coating develops on the filter grain surface when groundwater is treated via rapid sand filtration in drinking water production. Coating certainly changes the physical and chemical properties of the filter material, but little is known about its effect on the activity, colonization, diversity and abundance of microbiota
Until now, rapid sand filters have been a bit of a black box, says first author Arda Gülay,one of Smets' graduate students.
"In rapid sand filters, a combination of chemical, biological, and physical reactions help in the removal and precipitation of the impurities—iron, manganese, ammonia, and methane, for example," says first author Arda Gülay,one of Smets' graduate students. In time, the sand filter grains become coated with minerals, much of which the system managers remove, periodically, via backwashing.
It turns out that the minerals form an abundant matrix around the sand particles, sort of honeycomb-like. "Bacterial cell density in these structures can be very high, and can be boosted further when extra ammonium is provided," says Smets. The bacteria are normally engaged in removal of ammonium, manganese, and other impurities from the groundwater.
In fact, during the investigation, the ammonium-removal activity increased as the mineral deposits grew. "These positive mineral-microbe interactions suggest protective and supportive roles of the deposits," says Smets. The investigators also measured a high diversity of ammonium and nitrite-oxidizing species.
The researchers' direction involved a serendipitous twist. Early on, they discovered an unexpected positive correlation between the number of bacteria, and the degree of mineral coating of the sand particles, says Smets. "This was deemed worthy of further investigation, but we thought it would be a high risk effort. It was not until we saw actual cross sections of the mineral phases, which clearly reveal microbial cell like structures inside the deposits that we became aware of the unique discoveries we were making."
A major question the research raises is whether the microbes influence the development of the microporosity, or simply take advantage of it, says Gülay. Either way, it could lead ultimately to steering the mineralization to create micro-structures designed to house microbial cells to perform specific functions.
The manuscript can be found online at http://bit.ly/asmtip1014a. The final version of the article is scheduled for the November 2014 issue of Applied and Environmental Microbiology.
Applied and Environmental Microbiology is a publication of the American Society for Microbiology (ASM). The ASM is the largest single life science society, composed of over 39,000 scientists and health professionals. Its mission is to advance the microbiological sciences as a vehicle for understanding life processes and to apply and communicate this knowledge for the improvement of health and environmental and economic well-being worldwide.
Garth Hogan | Eurek Alert!
Litter is present throughout the world’s oceans: 1,220 species affected
27.03.2017 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung
International network connects experimental research in European waters
21.03.2017 | Leibniz-Institut für Gewässerökologie und Binnenfischerei (IGB)
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
28.03.2017 | Life Sciences
28.03.2017 | Information Technology
28.03.2017 | Physics and Astronomy