Wissenschaft
Bacteria as a hope for oil-contaminated waters
If an oil tanker has an accident and spills massive quantities of oil, it’s a major natural catastrophe: Flora, fauna and wildlife will inevitably suffer as no highly efficient means of cleaning spills have yet been found. This could soon change, however, as German researchers from Braunschweig and Bielefeld recently reported in Nature Biotechnology (Online, 30 July). For the first time, together with colleagues from Italy and Spain, they have succeeded in decoding the genome of an important oil-consuming sea bacterium. With the biochemical tricks employed by this bacterium, the scientists hope that new methods for cleaning oil-contaminated water can be developed.
Microorganisms with high-energy fuels on their menu have been well known for some time. For example, small quantities of oil constantly leak into the Gulf of California, and there, bacteria with oil-consuming abilities have utilized the leakages as a niche source of food. According to estimations, several million of tons of the Earth’s precious water are contaminated with oil each year, and there are still no truly efficient cleaning strategies. This is why researchers have set themselves the task of exploring the biochemical activities of these natural oil-eaters a little closer. As German scientists of the University of Bielefeld and the Helmholtz Center for Infection Research (Helmholtzzentrum für Infektionsforschung, HZI) in Braunschweig, together with Italian and Spanish colleagues, have now reported in Nature Biotechnology, they have been the first to decode the genome of Alcanivorax borkumensis - one of the most important oil-consuming bacteria. "It can live exclusively on hydrocarbons, from which oil is made up and, after the genome sequencing, we also know why and how: The bacterium produces a veritable arsenal of extremely effective oil oxidizing enzymes", says Vitor Martins dos Santos of the HZI. What’s more, the bacterium clearly possesses a number of transport systems for nitrogens, phosphates and iron - the very substances needed to diminish carbon compounds in oil. In fact, these mechanisms employed by Alcanivorax borkumensis are apparently so good that the water is filtered for longer than by other organisms.
Bacteria’s biochemical tricks used for environmental protection
The knowledge about natural oil consumers is of special importance for environmental protection: Their biochemical tricks could be used purposefully in the cleaning of oil-contaminated waters. One possibility would consist of isolating the enzymes used by the bacteria to dismantle oil, and distributing them in the oil slick. The direct use of bacteria in an oil slick would also be conceivable, according to the researchers. With the assistance of genome sequencing, the biochemical procedures can now be analyzed in detail, with a mind to constructing and developing efficient cleaning strategies. Furthermore, the decoded genome sequence of Alcanivorax borkumensis could be of medical use. "The bacterium forms a bio film in the boundary layer between oil and water, and these also play an important role in the settlement of pathogens in the human body", explains Kenneth Timmis of the HZI. A deeper understanding of the fundamental operational sequences of such bio films could therefore also be of great interest one day.
The sequencing as part of a German competence network
The sequencing of the bacteria genome took place within the German competence network ‘Genome research into bacteria for environmental protection, agriculture and biotechnology’. Created in 2001, it is one of three networks initiated by the German Federal Ministry for Education and Research (BMBF) which are involved in bacterial genome research. The coordination is led by the University of Bielefeld. The more than 20 research groups of the competence network originate from universities, other academic institutions, research establishments and industrial enterprises, spanning many of the Federal states of Germany. Content wise, the network is divided into three groups: agriculture, environmental protection and biotechnology. Alongside the oil-diminishing bacterium, the genomes of the plant-growth promoting bacterium Azoarcus Sp. and the pest Xanthomona campestris pv. vesicatoira have also been decoded. When founded, the network was equipped with funds totalling 11 million Euros by the BMBF and the government of the Federal state North Rhine-Westphalia. Now, the network has been granted another seven million Euros by the BMBF to be able to continue its work in the coming three years.
You can find more detailed information on the work of the network here.
