TU Freiberg: First Double Doctorate with University in Chile
Mr. Gerardo Retamal-Morales had done most of his work at the Universidad de Santiago de Chile, but significant research was also carried out at the Institute of Biosciences at TU Bergakademie Freiberg.
Mr. Retamal-Morales succeeded in isolating bacteria that can tolerate high concentrations of arsenic from waters at the Wismut mine – a remediated uranium mine in the Eastern part of Germany. While studying these bacteria, he also investigated a strain of bacteria that had previously been isolated from the arsenic-contaminated “Rauchbloesse” at Muldenhuetten near Freiberg, a waste heap where hundreds of years of smelting activity had deposited toxic ash and flue-gas particles. Mr. Retamal-Morales showed that these bacteria were able to excrete chemical compounds that could bind arsenic outside their cell walls. In order to verify the presence of these compounds, he developed a test that exhibits a color change when arsenic-binding compounds are present in a liquid. Gerardo Retamal-Morales isolated the compound and was able to show that it was "heterobactin B", a so-called siderophore, which is a compound that is actually present to enable the bacteria to absorb iron. Apparently, this compound can also be ‘misused’ to keep arsenic away from the cell and, thus, to prevent it from harming the bacteria. He analyzed the genome of a strain of bacteria that excreted a particularly high amount of an arsenic-binding compound, and investigated the conditions under which its genes are formed. As well as protecting bacteria from arsenic, such compounds may also influence the mobility of arsenic in the environment, such as its solubility in water or its uptake in plants.
From the beginning, Gerardo Retamal-Morales’s dissertation had focused on German-Chilean cooperation, especially since arsenic contamination is a problem in both countries and, in a Germany context, in Freiberg and the Erzgebirge in particular. His supervisor in Chile, Prof. Gloria Levicán, was happy to receive samples and strains from Germany. “The work of Mr. Retamal-Morales shows that the laboratory in Santiago and our laboratory complement each other very well in terms of experience and equipment,” said Prof. Michael Schlömann. “In addition, all of our guests from Chile have worked both hard and well to date, and have integrated themselves very well into the working group.”
The double doctorate offers PhD students the opportunity to get to know the scientific system of the other country, as well as the language and culture of the host country over a longer period of time. “For TU Freiberg, Chile plays a special role in the internationalization of doctoral funding, partly because intensive cooperation already exists with several institutes here,” said Dr. Kristina Wopat, Director of the Centre of Advanced Study and Research (GraFA) at TU Freiberg. Chile’s special role is a natural result of its geology and associated activities in mining and metallurgy, which offer starting points for cooperation with TU Freiberg across many fields. It also results from the high and improving academic standard of a number of Chilean universities as well as from the standard of infrastructure and security in the country, which together make it possible to exchange students in both directions. After a memorandum of understanding for general cooperation with the Universidad de Santiago de Chile had been renewed in November 2016 during a visit to Chile by Rector Prof. Klaus-Dieter Barbknecht, the double-doctorate contract was signed on the occasion of the opening of the ‘Chile Haus’ in Freiberg in October, 2017. The Chile Haus was made possible by a generous donation to the Bergakademie by Dr. h.c. Erika Krüger, and was made available specifically for the promotion of exchange with Chilean institutions. Gerardo Retamal-Morales was one of its first residents.
Contact person: Prof. Michael Schlömann, Tel +49(0)3731 / 39-3739