Ulrike Kappler

Biography

After the completion of my PhD at the University of Bonn (Germany) in 1999 I took up a postdoctoral position at UQ and subsequently, in 2003, I was offered a three year UQ Postdoctoral Fellowship which enabled me to develop my own research interests. In 2006 I was appointed to a lectureship for Biochemistry and Molecular Biology at UQ and from 2008-2012 I held an ARC Australian Research Fellowship. Brief Research Description: Microbial physiology and biochemistry of metalloenzymes

Research Interest

Energy generation from inorganic compounds, including inorganic forms of sulfur, is one of the special properties of many bacteria. This process contributes significantly to the biogeochemical sulfur cycle, to the bioavailability of sulfur for plant growth in soils and to the detoxification of various volatile sulfur compounds, some of which are known to be climate active. In addition there is evidence that enzymes turning over sulfur compounds can contribute to bacterial virulence. We are interested in investigating the metabolic pathways and enzymes involved in these processes, as well as their role in these very different types of microorganisms. Sulfite oxidizing enzymes - what makes them indispensable for living cells? Sulfite oxidizing enzymes are found in almost all types of living cells, and especially bacteria are known to harbour a great variety of these enzymes. However, it is unknown what the metabolic role of sulfite oxidation is. We are investigating the diversity of these enzymes, the reactions catalyzed by the three structurally distinct known types of these enzymes with a view to uncovering the role of these evolutionarily old enzymes for cellular function. Sulfur oxidizing extremophiles and biotechnological applications Alkaliphilic sulfur oxidizing bacteria have only been discovered in the last decade, and they have a unique potential for use in biotechnological applications designed to remediate sulfur pollution in waste streams and biogas. Many of the volatile sulfur compounds that are common pollutants in industrial and municipal waste as well as by-products of biogas manufacturing processes show increased solubility at the high pH values at which these bacteria thrive. Following chemical stripping of the volatile compounds from e.g. gases, the bacteria can be used to transform them into insoluble, biogenic sulfur, which can then be removed from the process. Metalloenzymes and bacterial pathogenesis Metalloenzymes are involved in key energy-generating processes in living cells, and they contribute significantly to the adaptation of microorganisms to different environmental conditions. This project investigates how respiratory enzymes can aid pathogens in colonizing specific niches in the host and how these enzymes might be exploited as future drug targets. Collaborators My group has extensive collaborations with research groups overseas and at UQ and other Australian Universities. Secondary Research Areas: Science Education Structural Biology and Biochemistry