Extended abstract
We have decided to tackle a very imposing ecological problem that is becoming more and more
threatening. Fossil fuels, such as oil and gasoline, have gained popularity in the beginning of the 20th
century. It is estimated that we have spent between 100 and 135 billion tons of oil since 1850 and
the demands are still increasing. Fossil fuels are used in cars, airplanes and other vehicles, to power
electricity plants, to heat our homes and to make many everyday products, such as medicines,
cosmetics, plastics and synthetic fabrics. Our society is largely dependent on them, but fossil fuels
take millions of years to form and are therefore a non-renewable resource. According to some
projections, we only have enough oil for the next 40 years, so it is becoming increasingly necessary to
find an alternative method of obtaining fuels.
Our first thought was to make use of butanol. Research has already shown that because of its long
chain and consequent nonpolarity, butanol could, amongst other uses, replace gasoline in internal
combustion engines. In nature, many organisms have been proven to be able to produce butanol by
converting glucose into acids and then converting acids into alcohols. This organisms, mostly bacteria
of the Clostridium genus (Clostridium acetobutylicum, Clostridium beijerinckii and Clostridium
saccharoperbutylacetonicum), however, have complex metabolism, slow conversion rate and are
often hard to grow in laboratories or for industrious use. For these and other reasons, they are
unsuitable for larger butanol production. On the other hand, bacteria E. coli have relatively simple
and strikingly fast metabolism, already researched and utilized mechanisms for genetic manipulation
and are easy to grow and cultivate, making them the perfect laboratory and industrial organisms.
Laboratory for Environmental Sciences and Engineering at the National Institute of Chemistry in
Ljubljana has been engaged in advancing processes that enable conversion of waste and renewable
raw materials into energy for a long time now, but they have recently also developed a mechanism
for direct biological conversion of waste to hydrogen by the means of using microorganisms. A series
of intermediate products is produced, glycerol and high concentrations of butanoic acid amongst
others. Incidentally, these are the two most important substances for our E. coli conversion
mechanism, as we could boost their butanol production and achieve good conversion rates and high
yield of butanol for biofuel, by genetically manipulating the E. coli bacteria into performing only the
second phase of butanol production found in Clostridium bacteria (acids to alcohols conversion).
By using this waste products we could make use of all of the components involved in this processes,
while also producing the much-needed biofuel, thus completing the circle of waste recycling, all
while being eco-friendly. Our aim is to compose an optimized system of bioreactors with which we
will be able to produce pure butanol as well as successfully use all side products formed. In the first
stage the biogas will be isolated out of organic waste and the remaining sediment shall be used as
natural fertilizer. At the same time the butanoic acid formed will be redirected in another bioreactor
where it will be converted into biobutanol.