Primary research interest

Microbial physiology and biochemistry of metalloenzymes

About me

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. I am a Fellow of the Australian Society of Microbiology (since 2011).

Research focus and collaborations

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.


My group has extensive collaborations with research groups overseas and at UQ and other Australian universities.

Funded projects

  • NHMRC Project Grant 2015-2019
    Immune recognition of upper airway microbiota in early life as a determinant of respiratory health in children
  • NHMRC Project Grant 2013-2015
    Metabolism-driven interactions of non-typeable Haemophilus influenzae and its host: a critical factor in infection?

Teaching interests

Microbiology, molecular biology and protein chemistry, general biochemistry:

  • BIOL1020, Genesm Cells & Evolution
  • MICR3003, Molecular Microbiology
  • MICR3004 Microbial Genomics
  • BIOC3005 Systems Biology.
  • BIOC3005 (Coordinator)

Achievements and awards 

  • Fellow of the Australian Society of Microbiology
  • ARC Research Fellowship
  • UQ Postdoctoral Fellowship
  • Chair of the ASM Qld branch committee
  • Member of the ASM National Council
  • Grant panel member NHMRC (2016 & 2017)
  • Review Editor for Frontiers in Microbiology

Featured publications

Publications by Ulrike Kappler

Researcher biography

Associate Professor Kappler (ORCiD: 0000-0002-2642-1319) is Group Leader in the School of Chemistry and Molecular Biosciences at UQ, and Chair of the Metals in Biology group. She held an ARC Australian Fellowship (2008-12) and has proven expertise in managing research projects funded by ARC & NHMRC project grants (>$2.5 million) as well as funding from other agencies. A/Prof. Kappler has > 20 years experience in bacterial physiology and the investigation of enzyme function and metabolic pathways in a wide variety of bacteria, with a particular focus on bacterial sulfur metabolism. Over the past ~10 years she has developed an extensive program of research on the physiology and pathogenesis of the human respiratory pathogen Haemophilus influenzae. Her laboratory is investigating the role of H. influenzae metabolism for host-pathogen interactions, as well as molecular defences against antimicrobials produced by the human immune system (publications: Front. Microbiol., 2015, 2016, 2021, Res. Microbiol. 2018, Adv. Microb. Physiol. 2019, 2xACS Infect. Dis. 2020) Her research has contributed to the development of a novel model of H. influenzae infection that is based on primary human nasal cells differentiated at Air-Liquid Interface.

A/ Prof. Kappler is regularly invited to present her work at international conferences (GRCs, MoTec, EMBO Microbial Sulfur Metabolism, Biometals), and has extensive expertise in the successful supervision of research students and has graduated 10 PhD, 24 Masters and 28 Honors students. She has been the Chair of the UQ Institutional Biosafety Subcommittee (2018-2021), and is the current Chair of the Australian Society for Microbiology (ASM) Queensland branch committee and a member of the ASM national council.