Biography
Msci Physics, Queen Mary College, University of London (2000)
PhD Theoretical Soft Matter Physics, University of Edinburgh (2004)
Visiting Scholar, Physics, Heriot-Watt University (2006)
Post-doctoral Research Associate, Biological Physics, University of Edinburgh (2006-2008)
Post-doctoral Research Associate, Mathematical Biology, University of Glasgow (2008-2012)
EPSRC mobility researcher co-investigator, Plant Metabolism, University of Cambridge (2012-2013)
Research
I am interested in microbes, in particular microscopic bacteria (e.g. soil rhizobia) and algae (e.g. ocean phytoplankton). My research focuses on the new physics required to understand swimmming microorganisms, from single cells to populations. Unlike passive microscopic particles (e.g. colloids), swimmers self-propel and actively respond to environmental bias (gravity, flow, light, chemicals...). Thus, swimmers suspensions often behave in a markedly distinct way from ordinary colloidal suspensions. A classical example is bioconvection, spontaneous large scale convection in shallow layers of swimmer supsensions (without a vertical temperature gradient, as in classical Rayleigh–Bénard convection). Typical environments for my swimmers are tubes, channels and porous media, as inspired by current problems in sustainable bioengineering and environmental microbiology.
The new physics of swimmers, and the application of physics to microbial biology and ecology in general, has the potential to improve promising bioengineering applications. My research centers around three such appplications: (1) removing pollutants from soil using bacteria (bioremediation) (2) growing algae in ponds and tubes for their products (photobioreactors). I use a combination of mathematical modelling and experiments to solve problems inspired by these applications, such as the growth dynamics of gyrotactic swimming algae in air-lift photobioreactors. (3) understanding interactions between species in synthetic microbial communities to improve their productivity in terms of chemical synthesis of useul products or energy.
I am affiliated with the Biological and Soft Systems Sector (BSS) in the Cavendish Laboratory (Department of Physics). Within Cambridge University I also collaborate closely with the Deparments of Plant Sciences (Prof Alison Smith's group) and Department for Applied Mathematics and Theoretical Physics (Prof Ray Goldstein's group).
Publications
A. Hope, O. A. Croze, W. C. K. Poon, M. A. Bees & M. D. Haw
Resonant alignment of microswimmer trajectories in oscillatory shear flows
Phys. Rev. Fluids 1, 051201(R) (2016) DOI:10.1103/PhysRevFluids.1.051201
M. A. Bees & O. A. Croze, Mathematics for streamlined biofuel production from unicellular algae. Biofuels 5, 53 (2014) DOI:10.4155/bfs.13.66
O. A. Croze, G. Sardina, M. Ahmed, M. A. Bees & L. Brandt Dispersion of swimming algae in laminar and turbulent channel flows: consequences for photobioreactors J. R. Soc. Interface 10 20121041 (2013) DOI:10.1098/rsif.2012.1041
V. Martinez, R. Besseling, O. A. Croze, … , M. A. Bees, L. G. Wilson & W. C. K. Poon, Differential Dynamic Microscopy: a high-throughput method for the characterisation of microorganisms, Biophys. J. 103 525-534 (2012)
DOI:10.1016/j.bpj.2012.08.045 Nature Methods Research Highlight
O. A. Croze, G. P. Ferguson, M. E. Cates & W. C. K. Poon, Migration of chemotactic bacteria in soft agar: role of gel concentration, Biophys. J. 101 525-534 (2011) DOI:10.1016/j.bpj.2011.06.023
My full publication list can be found on my research group website and on my Research Gate page. Please also refer to my arXiv prerpints.