Academic Staff - Dr Osu Lilje

Areas of Interest

Chytrid morphology and function

Figure 3: Light microscope image of a chytrid colony with various stages of the life cycle represented.	Figure 4: Light microscope image of a mature chytrid sporangium releasing zoospores.	Figure 5: Fluorescent staining of a cell wall component of the sporangium and the rhizoids.

The phylum Chytridiomycota is an ancient group of zoosporic fungi. The fungi disperse via characteristic unwalled, zoospores in water which on settling form simple sporangia, with or without rhizoids, with or without connecting 'hyphae'. The term ‘chytrid’ is used to describe these zoosporic fungi.  Only minor economic benefit has been associated with chytrids in the past, which may have contributed to relatively little research on this diverse group of fungi.

More attention is now focused on chytrids because of their association with disease in amphibians resulting in the world decline of amphibian species; presence in the gut of a number of economically important herbivores where they digest complex substrates: parasitic association with algae and phytoplankton which would have an impact on freshwater ecology and food web relationships; and their role as parasites in the coevolution of host and parasite species. The nutrition of chytrids is important in each of these roles. Information from ultrastructural and molecular studies is needed, to indicate how energy is gained from the environment and used within the microbe.

The specific questions I address are: What are the ultrastructural and molecular changes associated with different stages in the life cycle of this diverse phylum? How is energy obtained from the environment and utilized in the organism? What structures are associated with energy absorption?

Understanding how different types of chytrids use energy will indicate how they interact with their environment.

Soil chytrid growth responses to environmental changes in vitro

Figure 1: SEM micrograph of chytrid colony on a substrate.	Figure 2: Computer-aided tomography 3D images, a) chytrid (yellow) distribution in air-spaces (blue) in an artificial substrate, b) 3D modeling of chytrids alone.

Soil is an important global store of carbon. In addition, organic carbon is crucial to the sustainable management and productivity of soil. However, we are profoundly ignorant of the mechanisms and processes of storage and protection of organic carbon in soil. Fungi assist in the process of generating and storing carbon by aggregating soil particles in which the organic carbon is stored and protected. My research looks at the mechanisms underpinning the development of 3 dimensional aggregates in soil by soil chytrids.

Characteristics of chytrid biofilms

Figure 6: Light microscope and fluorescent image of a chytrid colony with red fluorescent labelling of a biofilm component.	Figure 7: Transmission electron micrograph of rhizoids connected by biofilm.

Biofilms produced by organisms play an extraordinarily important role in the functioning of organisms. While we now have a clear understanding of the role of bacterial biofilms produced by pathogenic bacteria in human artificial joints and tooth decay, for instance, the ecological role they play in fungi, and especially chytrid fungi, is less well understood.

Soil chytrids make up a portion of the microbial community involved with biodegradation of plant and animal polymers. Under laboratory conditions thalli of many species of chytrids aggregate and form colonies. Colonies result from the zoospores becoming entangled in the rhizoid branches of thalli. The presence of a biofilm on the surface of rhizoids and sporangial cell walls appears to facilitate attachment to surfaces, and may be important in the formation of colonies and attachment of colonies to their substrate. My research looks at the properties of the biofilm, its role in chytrid aggregation and carbon sequestration in soil.

Opportunities

Postdoctoral

If you are interested in postdoctoral research, please contact Osu. The University offers a number of attractive postdoctoral fellowships - please consult the Research Office for more information.

Honours

People interested in completing an honours project are also welcome. The honours degree at The School of Biological Sciences consists of a research thesis written as a scientific paper (80%) and coursework (20%) comprising an experimental design course, writing a formal research proposal for your project, and a written paper criticism. Students are encouraged to develop their own ideas, but if you would like some suggestions in your broad interest area, send Osu an email. A prerequisite to enrol in hounours is a WAM or equivalent undergraduate average of >70%.

Postgraduate (PhD, MSc)

If you are interested in postgraduate study in a research area related to Eco-mycology send Osu an email to discuss possible projects.

A prerequisite for a postgraduate candidature is a scholarship that covers living allowance in the case of Australian students, but also tuition fees for international students.

For Australian students, there are the Australian Postgraduate Awards (APA), as well as University of Sydney Postgraduate Awards (UPA), and Faculty of Science Postgraduate Awards - the Research Office has more information about these scholarships.

If you are an International student, it will be worthwhile to check whether your government provides scholarships for postgraduate study abroad. The Australian government offers the Endeavour International Postgraduate Research Scholarships (EIPRS) for research based postgraduate study at an Australian university for students from overseas; more information on EIPRS is provided by the International Office.

Discipline Research

• Neuhauser, Sigrid, Sally L. Glockling, Eduardo M. Leaño, Osu Lilje, Agostima V. Marano and Frank H. Gleason. (2012). Chapter 9 - An introduction to fungus-like microorganisms, In Marine Mycology- Marine fungi and fungal-like organisms, labyrinthulomycetes and oomycetes, Jones, E. B. Gareth and Pang, Kai-Lai, Eds., De Gruyter, Germany, pp. 127-141.(In Press)
• Gleason, Frank H., Laura T Carney, Osu Lilje and Sally L. Glockling, (2012). Ecological potentials of species of Rozella (Cryptomycota). Fungal Ecology (In press).
• Gleason, F.H., Crawford, J.W., Neuhauser, S. Henderson, L. and Lilje, O. (2012). ‘Resource seeking strategies of zoosporic true fungi in heterogeneous soils habitats at the microscale level.’ Soil biology and Biochemistry, 45: 79-88.
• Gleason, F. H., A. V. Marano, A. L. Digby, N. Al Shugairan, O. Lilje, M. M. Steciow, M. D. Barrera, S. Inaba, A. Nakagiri and P. A. McGee. (2011). Patterns of utilization of different carbon sources by some Chytridiomycota. Hydrobiologia. 659:55-64.
• Gleason, F.H., Küpper, F.C., Amon, J.P., Picard, K., Gachon, C.M.M. , Marano, A.V., Sime-Ngando, T. and Lilje, O. (2011) ‘Zoosporic true fungi in marine environments: a review’. Marine and Freshwater Research 62: 383-393.
• Gleason, F. and Lilje, O. (2009) ‘Ecology of fungal zoospores: structure and function in aquatic habitats’ Fungal Ecology 21:53-59.
• Lilje, O. and Lilje, E. (2008) ‘Fluctuations in Rhizophydium sp. (AUS6) zoospore production and biomass during colony formation’ Australasian Mycologist 27(1):20-32.
• Lilje, O. and Lilje, E. (2007)‘Ratiometric pH measurements in living nephrocytes using confocal scanning microscopy’ Progress in biomedical optics and imaging’in Imaging, Manipulation, and Analysis of Biomolecules, Cells, and Tissues V, edited by Daniel L. Farkas, Robert C. Leif, Dan V. Nicolau, Proceedings of SPIE Vol. 6441 (SPIE, Bellingham, WA, 2007) 64411Q
• Lilje, O. and Lilje, E. (2006) ‘The response of the vacuolar reticulum of Saprolegnia ferax to the presence of GTPase modulator, GTP-S’ Australasian Mycologist 24(3):69-80.
• Lilje, O. and Lilje, E. (2006) ‘Comparative imaging of the vacuolar reticulum of Saprolegnia ferax’ in Imaging, Manipulation, and Analysis of Biomolecules, Cells, and Tissues IV, edited by Daniel L. Farkas, Dan V.Nicolau, Robert C.Leif, Proceedings of SPIE Vol. 6088 (SPIE, Bellingham, WA, 2006):60881F1-11.
• Lilje, O. (2004) ‘Quantitation of cytoplasmic calcium in growing Saprolegnia ferax hyphae using Indo-1 and two-photon confocal microscopy’ Australasian Mycologist 22:3.
• Lilje, O. (2003) ‘Measuring calcium levels in Saprolegnia ferax using the two-photon laser scanning microscope’, in Proceedings of SPIE Vol. 4963Multiphoton Microscopy in the Biomedical Sciences III, edited by Ammasi Periasamy, Peter T.C.So, (SPIE, Bellingham, WA,2003) :1605-7422.
• Lilje, O. (2002) ‘The processing and presentation of endogenous and exogenous antigen by Schwann cells in vitro’ Cell.Mol.Life Sci. 59:2191-2198
• Lilje, O. and Armati, P.J. (1999) ‘Restimulation of resting autoreactive T cells by Schwann cells in vitro’ Experimental Molecular Pathology 67:164-174.
• Lilje, O. and Armati, P.J. (1997) `Observing the temporal and spatial distribution of MHC class I, II and ICAM-1 on Schwann cells in vitro' Journal of Neuroimmunology 77:75-84.
• Lilje, O. and Armati, P.J. (1995) `An improved protocol for immunogold staining for scanning electron microscopy (SEM) of cultured cells' Journal of Neuroscience Methods 58:1-2.

Teaching Development and Educational Research

• Lilje, O. And Peat, M. (2010) ‘Teaching Human Biology to Large First Year Classes: an eLearning Journey for Students and Staff’ International Journal of Innovation in Science and Mathematics Education, 18 (2): 21-31
• Lilje, O., Breen, V., Lewis, A. and Yalcin, A. (2008) A pilot study on the impact of an online writing tool used by first year science students. In: Proceedings of the Symposium Visualisation and Concept Development, October 2-3, UniServe Science, Sydney p 54-59.
• Lilje, O., Breen, V., Lewis, A. and Yalcin, A. (2008) The structure, use and impact of the staff version of ORWET. In: Proceedings of the Symposium Visualisation and Concept Development, October 2-3, UniServe Science, Sydney p 188-192
• Lilje, O., Krishnan, S. and Peat, M. (2007), ‘Use and perceptions of a blended learning resource: Are student perceptions reflected in their performance?’ 10th Pacific Rim First Year in Higher Education (FYHE) Conference 4-6 July 2007: ‘Regenerate, engage and experiment’, Queensland University of Technology, Brisbane, Australia. http://www.fyhe.qut.edu.au
• Lilje, O. and Peat, M. (2007) ‘Use of traditional and elearning components in a blended learning environment’, UniServe Science Teaching and Learning Research Proceedings, 177-180.
• Lilje, O. and Peat, M. (2006) ‘Use and perceptions of use of a blended learning resource: are students engaging with the materials?’ 9th Pacific Rim First Year in Higher Education (FYHE) Conference 12-14 July 2006: 'Engaging Students'. Griffith University in conjunction with Queensland University of Technology, Gold Coast, Brisbane, Australia. http://www.fyhe.qut.edu.au