In today's fast-moving world, many forms of human activity require ever more
precise and sophisticated technology – either to perform a particular, specialised
function, or to provide reliable means of micro-screening and analysis.
© Fotolia, 2012
The rapidly evolving spheres of biotechnology and nanotechnology provide many of the required solutions. Frequently the two are combined - in the form of nanobiotechnology.
One area where demand for this technology is
strong is that of membranes for microsieves –
nanoscale filtration methods, which play a key
role in the analytical systems, used in areas
such as food processing, drug discovery or
medical diagnostics. anoporous membranes
and microsieves can be used to eliminate, or
to detect the presence of microbes in drinking
water, such as Legionella or E.coli. In the
biomedical field, they can be used to detect
tiny differences or abnormalities among cells.
They are even used as a way of ascertaining
An unlikely but extremely fertile source of
new discoveries and materials to assist with
this technology is the seabed - in the cold
zones where no light penetrates.
Life originated in the sea. The oldest animals
still in existence are the sea sponges. And,
incredibly, it is these animals, the most ancient
form of life on earth, that are now making a
vital contribution to the world's most modern
science. This phenomenon is at the heart of
Mem-S, a research project funded under
the EU's 7th Framework Programme with
the aim of using cutting-edge molecular
biology techniques to design and fabricate
nanoporous membranes and microsieves
with new and innovative capabilities for use in
Begun in 2010, the three-year project, leaded
by the University Medical Centre of the
University of Mainz, involves three researchbased
SMEs and four universities and research
institutes from Germany, the Netherlands,
Austria and France.
Sea sponges contain a number of enzymes
and proteins. One of these is silicatein, the only
known enzyme in existence with the capability
of synthesising an inorganic polymer, silica,
from an inorganic precursor molecule.
This silica (or biosilica) is what forms the
sponge's skeleton. However, its key property
combinations, including light transmission
and extreme stability – unlike technical glass,
which breaks easily – make it valuable for a
range of advanced technological applications.
Just as importantly, the silicatein needed to
form the silica can be produced in a sustainable
way by a process of genetic engineering,
inserting the sponge gene into bacteria.
In the Mem-S project, this breakthrough technology
is linked with another cutting-edge
development – so-called 'S-layer' (crystalline
bacterial cell surface layer) technology. The
beauty of S-layer proteins is that they assemble
themselves in highly ordered structures
of defined pore size and shape – a feature
that makes them ideal for use as nanoporous
membranes in microsieves.
By binding to the silica, enzymatically produced
by the silicatein, the membrane gains
reinforcement and support, while the silica
can also be utilised to encase any specific biomolecules
needed for the individual filtration
or sensory function required.
The new technique will be exploited by the three
SME's involved in the project – the German
NanotecMARIN GmbH, and the Netherlands'
Lionix BV and Aquamarijn Micro Filtration BV, in
sensors in drinking water systems, in industrial
nanosieves and in microfluidics-based sample
processing and micro-array development.
The astounding properties of biosilica, meanwhile,
make it a promising material for use
in other areas such as microelectronics and
medical implant materials.
From sponge skeleton to microchips. It is an
incredible journey through space and time.
From the prehistoric depths of the sea, a
brave new world is indeed arising.