Anusuya Willis BSc (Hons), PhD


Research Fellow, Australian Rivers Institute, Griffith University, Nathan
Ph.D - Science (University of Melbourne and Université de Paris Sud)

Contact details:
Phone: +61 (0)7 3735 5359

Email: anusuya.willis@griffith.edu.au

Research Interests

Cyanobacteria cell biology

Cyanobacteria are photosynthetic prokaryotes that are particularly important in freshwater lentic ecosystems, where they can become dominant organisms causing harmful ‘blue-green algae blooms’. My research focuses on developing a deeper understanding of the cell biology of these organisms, with three main areas of research:

           From genes to population dynamics

I am interested in how cells respond to environmental changes. Particularly in understanding how the available gene sets for nutrient uptake and metabolism pathways translate into physiological traits that then lead to changes in population dynamics.

          Nutrient Uptake and Metabolism

Nutrients are an important aspect of cyanobacterial growth, especially nitrogen and phosphorus, which are essential for growth. Cyanobacteria are able to use a range of inorganic and organic nutrients. How the balance between growth and available nutrients in juggled in the face of a constantly changing environment remains one of big unanswered questions in freshwater ecology.

          Cyanobacterial Toxins

Many cyanobacteria produce secondary metabolites that are harmful to humans and other mammals. There is uncertainty around the environmental drivers of populations that lead to greater toxin production. Furthermore, the role of these metabolites for the cyanobacteria cell is largely unknown, making predictions of their production uncertain.

          Current Research Projects

Living in a high CO2 world: Impacts on freshwater phytoplankton populations from elevated atmospheric CO2.

Adaptive ecotyping of the toxic cyanobacterium Cylindrospermopsis raciborskii to predict its invasive capacity

The morphology and phylogeny of benthic cyanobacteria from Moreton Bay

  Previous Research

          Biofouling – diatom adhesion

I began my scientific research investigating the adhesion of fouling diatoms in the group of A. Prof. Rick Wetherbee at the University of Melbourne. During my honours project I created substrata with different surface-chemistries, to investigate how the adhesion of key fouling diatoms is affected by surface chemistry (Willis et al. 2007). For my PhD I took this work further, working under the supervision of A. Prof. Rick Wetherbee and Dr. Chris Bowler, I used bioinformatics to identify potential genes for diatom adhesion molecules, reverse genetics for endogenous over-expression and examined their function in-vivo with a range of adhesion tests (Willis et al. 2013, 2014). 

         Biofuels – diatoms as feedstock for biodiesel

I spent a year at the Georgia Institute of Technology, Atlanta GA USA, in the group of Dr. Nils Kroger, investigating the potential to use diatoms as a feed-stock for biofuels. This work involved identifying key metabolic pathways for genetic engineering to increase the production of chrysolaminarin for subsequent ethanol production and triacylglycerol for biodiesel.

          Potential PhD topics 

  • Understanding nutrient use by cyanobacteria with a molecular ecology approach
  • Ecology of the harmful algae benthic cyanobacteria majuscula in Moreton Bay
  • Population dynamics of cyanobacterium strains

          Publications

  • Willis A., Adams M.P., Chuang A.W., Orr P.T., O'Brien K.R., Burford M.A. 2015. Constitutive toxin production under various nitrogen and phosphorus regimes of three ecotypes of Cylindrospermopsis raciborskii (Woloszynska) Seenayya et Subba Raju). Harmful Algae 47:27-34
  • Willis A., Parks M, Burford M.A. 2015. Draft Genome Assembly of Filamentous Brackish Cyanobacterium Limnoraphis robusta strain CS-951. Genome Announcement 3(5):e00846-15
  • Pierangelini M., Sinha R., Willis A., Burford M.A., Orr P.T., Beardall J., Neilan B.A. 2015. Constitutive cylindrospermopsin cellular pool size in Cylindrospermopsis raciborskii under different light and pCO 2 conditions. Applied Ecology Microbiology accepted.
  • Burford, M.A., Davis, T.W., Orr, P.T., Sinha, R., Willis, A., Neilan, B.A. 2014.  Nutrient-related changes in the toxicity of field blooms of the cyanobacterium Cylindrospermopsis raciborskii. 2014. FEMS Microbiology and Ecology 89, 135-148.
  • Willis A., Eason-Hubbard M., Hodson O., Maheswari U., Bowler C., Wetherbee R. 2014. Adhesion molecules from the diatom Phaeodactylum tricornutum (Bacillariophyceae): genomic identification by amino-acid profiling and in vivo analysis. Journal of Phycology 50, 837-849
  • Willis A, Chiovitti A, Dugdale T.M and Wetherbee R. 2013. Characterization of the extracellular matrix of Phaeodactylum tricornutum (Bacillariophyceae): structure, composition, and adhesive characteristics. Journal of Phycology 49(5), 937-949
  • De Martino A, Bartual A, Willis A, Meichenin A, Villazan B, Maheswari U, and Bowler C. 2011. Physiological and molecular evidence that environmental changes elicit morphological interconversion in the model diatom Phaeodactylum tricornutum.Protist  162 (3), 462-481
  • Bowler C. et al. 2008. The Phaeodactylum genome reveals the dynamic nature and multi-lineage evolutionary history of diatom genomes. Nature 456(7219), 239-244
  • Willis A, Dugdale T.M, Pacifico J, and Wetherbee R. 2007. Characterization of the adhesion of fouling diatoms onto test surfaces. J. Diatom Research 22(2), 457-471
  • Dugdale T.M, Willis A, and Wetherbee R. 2006. Adhesive modular proteins occur in the extracellular mucilage of the motile, pennate diatom Phaeodactylum tricornutum. Biophysical journal 90(8), L58-L60
  • Chiovitti A, Harper R.E, Willis A, Bacic A, Mulvaney P, and Wetherbee R. 2005. Variation in the substituted 3-linked mannans closely associated with the silicifed walls of diatoms. Journal of Phycology 41(6), 1154-1161