BIELEFELD, (Germany): The green energy of the future: A German-Australian
research team has succeeded in breeding algae, which produce hydrogen in
previously unheard-of quantities.
Amid rising oil prices and dwindling
energy reserves, a genetically altered alga is now nourishing visions of
an environment-friendly supply of energy.
Researchers from the University of
Bielefeld in Germany and the University of Queensland in Brisbane,
Australia, have genetically changed the single-cell green alga
'Chlamydomonas reinhardtii' in such a way that it produces an especially
large amount of hydrogen.
This gas can then be burned to produce
energy. In contrast to the use of fossil-based fuels such as petroleum,
coal or natural gas, no carbon dioxide is produced, but instead only
water.
It has been known for a long time that
certain algae can produce hydrogen during the photosynthetic process,
explains Bielefeld biologist Olaf Kruse. But the catch was efficiency, as
one litre of alga produces only about 100 ml of hydrogen. "Then it's over,
because the cells die off."
But the genetically altered variant
boosts this up to half a litre of hydrogen. By Kruse's estimates, it can,
in the long run, produce five times the volume made by the wild form of
alga.
Economic feasibility with regard to algae
sets in only when the energy efficiency - the conversion of sunlight into
hydrogen - reaches 7-10 percent. But alga in its natural form achieves at
most a meagre 0.1 percent. The new 'turbo-alga' has now come up to 1.6-2.0
percent.
"We have not reached our goal yet," says
Kruse, calmly announcing: "We want to reach it in five years."
At the end of the development process
could be a biological fuel cell in which the alga produces the necessary
hydrogen directly at the site of consumption. A motorist would then,
instead of a stop at the petrol pump, need only to have an alga power
plant on board.
This is naturally a futuristic vision.
Kruse has been working on such a 'turbo-alga' together with Ben Hankamer
of the Institute of Molecular Bioscience at the University of Queensland
since the year 2001. From a pool of 20,000 random mutations, the
scientists have selected 20 algae, ultimately coming up with a genetically
altered mutation called 'Stm6'.
Meanwhile, at the Technical University in
Karlsruhe, a prototype of a bio-reactor containing 500-1,000 litres of
algae cultures is being developed. The reactor is to be used to prove the
economic feasibility of the system in the next five years.
"What is of decisive importance is finding
a way of producing energy for which we won't need to import any
resources," Kruse says. On the basis of calculations, a reactor shaped
like a cube measuring three metres per side and filled with algae could
supply a two-person household with their energy needs. |