Plate or tank? This competition question was raised in view of limited agricultural land and of the simultaneous trends on biofuels and more clearly.
Researchers at the Technical University of Munich (TUM) will help to equalize the issue of priority: they are working on being poorly recyclable waste materials of crops effectively put to use for industrial production of bioethanol. But they take a close look at bacteria that convert cellulose into sugars and thus increase the yield of the energy used by plants. If that works, could get bread and biofuels in the future from the same field.
The age of diesel and petrol is inevitable to an end. But the alternative - bioethanol, which is produced by microorganisms from plant material - is the target of criticism. Because of this biofuel is currently produced from crops such as wheat, sugar cane or corn, more precisely, from the sugar that lies as a strength in them. But when using crops for the production of bioethanol, they fall away at the same time as food. Researchers at the TUM Department of Microbiology working on a solution to the dilemma. The idea: to make sugar for ethanol production available, which is stored in the form of cellulose in the stalks and leaves of plants. "Our goal is to get out of the previously little utilized industrial scale cellulose to make sugar, which can then be processed into ethanol," said microbiologist Dr. Wolfgang Schwarz.
But this is not so simple: The main component of plant cell walls, cellulose for the stability of the plant grow is responsible - and therefore made extremely stable: sugar molecules form cellulose molecules that form a chain-like and very robust connected tear-resistant fibers. It is therefore difficult to break down the cellulose into sugar stable. Fortunately, there are in real nature, enzymes that can do. They are, for example, bacteria are present, living in bovine stomachs. In this natural "bioreactors" they help to digest the grass and to release the sugar. However, the degradation of cellulose by the bacteria will take very long. Before cellulose on an industrial scale, efficient and profitable can be converted into biofuel, the process must be improved.
TUM-Chair of Microbiology faces this problem: on one hand researchers are looking for in the vast microbial diversity in nature, yet unknown cellulose-degrading enzymes to isolate the other hand it new cellulose-eating "microbes from nature in order to investigate further this. The research group of Dr. Black now takes the most promising of these bacteria under the microscope, Clostridium thermocellum . This soil bacterium has a total of 70 enzymes that allow the plant cell wall components, it can degrade the various. Thanks to this "tool box" bacterium adapts perfectly to its environment to: Depending on whether it in straw, leaves or wood waste lives around, produces C. thermocellum on its surface to another, effective enzyme complex for cellulose degradation.
This principle test the TUM researchers now in the lab: you want to use the tool kit of the bacteria to find optimum enzyme combinations for industrial cellulose degradation. To this end they have identified the most powerful and enzymes produced in vitro. These components were assembled into different combinations, the variations have selected the best microbiologists from the many possibilities. Jan Krauss was employed as a graduate student for three years thus: "Now we optimize the most effective combos for industrial application. Ultimately, we want to develop for any cellulosic plant residue decomposition an individual tool. With luck, we find the perfect enzyme mixtures, which can then be established in bio-ethanol plants. "
With its research program, the TUM researchers see the trend of industrial efforts: So constructed, Süd-Chemie AG Straubing in a pilot plant that converts straw as biogenic residues to bioethanol.
