Academic Profile : Faculty

Oliver Martin Mueller-Cajar_cropped_318_425.jpg picture
Assoc Prof Oliver Martin Mueller-Cajar
Associate Professor, School of Biological Sciences
Assistant Chair (Research), School of Biological Sciences (SBS)
External Links
I undertook my PhD studies under the supervision of Dr. Spencer Whitney at the Australian National University in Canberra, studying the artificial evolution of the photosynthetic CO2-fixing enzyme Rubisco. Subsequently I joined the laboratory of Dr. Manajit Hayer-Hartl at the Max-Planck Institute of Biochemistry near Munich, Germany, where I discovered a novel molecular motor that activates Rubisco. My group at NTU started in August 2012.
Photosynthetic organisms provide us with food and other materials by using light energy from the sun to capture carbon dioxide from the atmosphere to make usable sugars. Almost all CO2 enters the biosphere via the enzyme ribulose-1,5-bisphosphate carboxylase oxygenase (Rubisco). In spite of the crucial importance of this process Rubisco is non-specific and slow, which has forced nature to hugely overexpress the protein, or to use tricks such as biochemical or biophysical carbon concentrating mechanisms to saturate the enzyme with substrate.

The recent explosion of available sequence data has uncovered that Nature possesses a great diversity of Rubiscos and associated protein machinery to perform the task of CO2 capture, much of it poorly characterized. Research in my laboratory aims to mechanistically describe the biochemistry of CO2-fixation related machinery. By increasing our understanding of the sophisticated mechanisms that have evolved in remote branches of the tree of life, we hope to provide knowledge that can later be applied to improving the photosynthetic efficiency of crop species.

The journey has led from experiments exploring the artificial or directed evolution of Rubisco in E. coli to detailed structural and mechanistic investigations into molecular chaperones, so called Rubisco activases, that repair inactivated Rubiscos. Recently we have entered the realm of soft matter physics (liquid liquid phase separation) by exploring the manner by which microalgae compartmentalize the enzyme in a small volume to enable an increase of local carbon dioxide concentrations to be achieved.

Towards translating our interests we have also turned our attention towards the potential use of eukaryotic microalgae as a synthetic biology platform. This involves both the utilization and implementation of heterologous CO2 fixation machinery, as well as the potential to channel the photosynthate towards compounds of scientific and commercial interest.

We are always interested in hosting promising young scientists that have a clear idea in how their future plans intersect with the group's interests. For more information please also check our laboratory homepage:
  • Expanding the carbon fixation machinery of microalgae to enhance photosynthesis and biomass production
  • From protein droplets to oil droplets: understanding the role of WRINKLED1 phase separation in the biosynthesis of vegetable oils
  • Understanding the Birth, Life and Death of the highly specific red CO2-fixing Rubiscos to unlock enhanced photosynthetic efficiencies