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Making
food from water
Invisible but invaluable: raised
in steel tanks, a tiny marine creature is capable of producing Omega-3
fat, a product in great demand.
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FAT-RICH
FLOUR: SINTEF scientist Jose Rainuzzo shows off a
powder consisting of dried micro-organisms
that are rich in highly desirable fat.
Contact: Jose Rainuzzo,
SINTEF Fisheries and Aquaculture
Tel: +47 53 59 63 72
email: jose.r.rainuzzo@sintef.no
“To put it very simply, you could say that we are trying
to produce fish feed and dietary supplements from seawater”,
says SINTEF’s Jose Rainuzzo. More precisely, the Peruvian
scientist and his colleagues are exploring the properties
of a micro-organism that lives everywhere in the ocean.
The organism,Thaustrochytrids, has characteristics that place
it on the boundary of the plant and animal kingdoms. SINTEF
scientists believe that it could be a possible source of Omega-3
fat for aquaculture and for the health-food industry. |
| Photo: Rune Petter Ness |
FATTY ACID IN DEMAND
In laboratory tanks in Trondheim, these unicellular creatures are
being cultivated on a diet that consists of mostly sugar and salt.
After five or six days in the culture tank, they are full of the
fatty acid known as DHA (docosahexaenoic acid). DHA fat is important
in the diet of both babies and fish fry. It is incorporated in feed
for young fish and is added to baby food. Many people are also willing
to pay well for DHA in capsules from health-food shops.
ALTERNATIVE
TO FISH OIL?
Much of the demand for DHA fat is currently met by fish oil. But
the world’s fisheries are in crisis, having reached the ecosystem’s
limits, so the level of production of fish oil is unlikely to rise
in the future. According to Rainuzzo, therefore, microorganisms
could be useful supplementary sources of fat. Although it is much
more expensive to extract fat from such sources than from fish,
the tiny organisms in SINTEF’s tanks have a much higher content
of DHA than fish oil.
TEST-TUBES IN HOLIDAY LUGGAGE
Research into raising and exploiting these tiny fat factories has
been carried out with financial support from the Research Council
of Norway. Rainuzzo is a marine biochemist, and is collaborating
with biotechnology groups at NTNU and SINTEF, led by Professor Arne
Strøm and research scientist Inga Marie Aasen.
Thaustrochytrids lives everywhere there is
saltwater, not just in the sea, but even between the grains of sand
on the beach. When the project was started, the $64,000 question
was ‘Where can we find strains that grow rapidly and produce
large amounts of DHA?’ People from Aasen’s group who
vacationed on the coast brought samples of seawater and beach sand
home with them. With this material, SINTEF scientists and research
fellow Anita Nordeng at NTNU were able to home in on two strains
of the organism: one from somewhere in the Atlantic and the other
from the coast of southern Norway. For the last several years, the
team has been developing methods of cultivation that produce high
concentrations of cells in the tanks, high fat content in the cells,
and a high proportion of DHA in the fat.
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Photo: Anita Nordeng,
NTNU
TINY
FAT PRODUCERS: This is what the micro-organisms known
as Thraustochytrids look like. The largest of them are only
0.2-0.3 millimetres in diameter. |
FROM MEAL TO OIL
So far, the Trondheim scientists have made a kind of flour from
the micro-organisms. Rainuzzo has successfully fed the flour to
rotifers, a type of zooplankton used to feed cod and halibut fry.
When the rotifers eat the flour, they absorb the valuable fat and
in turn make it available to the fry. Rainuzzo has also fed the
flour directly to cod fry along with rotifers, and has seen the
fry eat the flour. SINTEF has recently applied to the Research Council
for funding for the next stage: designing a process for extracting
fat from the micro-organisms in the form of oil, leaving the flour
as a by-product. “If we want to build up an industry from
this process, producing oil will be decisive,” according to
Rainuzzo.
HIGH PRICE
Two plants in the USA are currently producing Omega-3 from marine
micro-organisms. One of them produces oil,which it sells to manufacturers
of baby food for $250 per kilo. Rainuzzo envisions a Norwegian plant
that would sell oil to the health food industry and to fish food
manufacturers, along with flour to fish-fry producers in the aquaculture
industry. Currently, large quantities of fish oil are used as an
additive in feeds for adult fish. Rainuzzo thinks there could be
an alternative for this market: a mix of expensive microorganism-
produced oil, rich in DHA, combined with low-DHA oil from vegetable
sources.
“If the aquaculture industry is to
grow, sooner or later there will not be enough fish oil for feedstuffs.
When that happens, alternative oils with DHA fat could become big
business,” he says.
Svein Tønseth
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