Team:Slovenia HS/Extended abstract

Team Slovenia_HS: Extended abstract

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.