Mark-van-Loosdrecht-EN

‘As an engineer, you have to
interpret your observations and
convert them into knowledge’
field of extracting raw materials.
This, too, includes new fundamental
insights that lie at the basis of possible
applications. “Until now, there was
a different explanation for the role of
storage polymers. It was thought that
fat reserves were the result of limiting
conditions, such as the availability of
nutrients. However, it is actually an
intrinsic mechanism for adapting to
dynamic conditions, such as day and
night rhythms and the effects of the
tides. This means that bacteria do not
have to grow as quickly as possible
in order to win the competition in an
ecosystem. They have developed all
kinds of mechanisms for making the
most of those variable conditions.”
These are the mechanisms of
which he wishes to gain a greater
understanding, and which he wishes
to apply. “We are now looking at
whether we can make processes
based around that kind of specialised
bacteria. It concerns not just waste
water, but also other waste flows. The
quantities of organic material that are
lost, in the cultivation of tomatoes,
for example, are enormous. You can
remove the fibres from the stems,
but that still leaves a type of pea
soup containing a complex mass of
all kinds of organic compounds. We
are looking for ways of making one
or two usable compounds from that
body of organic material that have
multiple applications.” Alginates,
for example, can serve as a raw
material in the production of paper,
textiles, foodstuffs, cosmetics, and
medications.
Much is happening in this field as
well. TU Delft recently concluded a
so-called Green Deal with Attero, the
Venlo city council, and bioplastics
company Novamont, among others,
for making biodegradable plastic
bags from biodegradable waste that
are actually used for collecting the
biodegradable waste, thereby creating
a closed loop. Part of that process
involves another special bacterium
discovered in Van Loosdrecht’s
laboratory, the plasticicumulans, which
has the unique ability to convert the
fatty acids that are released during
the fermentation of biodegradable
waste into the bioplastic PHA. Another
example is a new method for enabling
algae to produce lipids in a highly
efficient manner. This could represent
a breakthrough for the large-scale
production of dietary fats or biodiesel.
“Anyone wishing to produce biodiesel
usually looks for an organism that
is well able to do so and applies it in
axenic cultures. We take a slightly
different approach. We do not simply
conduct a search and then work in a
sterile manner. We are investigating
the role of lipids in microbial ecology
and then set up an ecosystem in which
the organism that makes more lipids
than another is more successful. We
call it ‘survival of the fattest’.” This
ecology-based approach is, believes
Van Loosdrecht, the reason that so
many processes emerge from TU
Delft. “The industrial microbiology
sector works with known organisms
and modifies them. But of all the
microbial life on earth, the proportion
with which we are familiar amounts
to just a few per cent. We use the full
100%, and from that selection there is
inevitably an organism that produces
to an optimum level, and usually it
was not previously known. Most
researchers think at the metabolic and
genome level. We look at the ecology,
and that is unique.”
Trophy cabinet
The Simon Stevin Meester prize 2013 is by no means the first award that
Mark van Loosdrecht has won. In 2012, he was awarded the prestigious Lee
Kuan Yew Water Prize in Singapore, and in 2011 he became a Knight in the
Order of the Netherlands Lion. In 2010, he received an honorary doctorate
from the Swiss university of technology, ETH Zurich, and before that, in
2007, the Dow Energy Prize. These are just a few examples. Van Loosdrecht
hastens to add that the honour is not just his, and neither are the prizes.
“Fortunately, Nereda wins many prizes, so everyone at least has a turn.”
Also of note is that this year the American Association of Environmental
Engineering and Science Professors (AEESP) named Van Loosdrecht
Distinguished Lecturer of the Year. “I will be visiting the twenty leading
environmental study programmes to give lectures and to talk with the
students and staff.”
Highlights TU Delft 2013
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