Olivia Sackett, PhD candidate
Topic: Species-specific macromolecular composition and carbon productivity of Southern Ocean microalgae
Supervisors: Associate Professor Peter Ralph (UTS), Professor John Beardall (Monash University), Dr Phil Heraud (Monash University), Dr Martina Doblin (UTS) and Dr Ross Hill (UNSW)
Photosynthesis by marine microalgae constitutes approximately half the earth's primary production, thereby supporting both marine and terrestrial ecosystems. The nutritional value of microalgal communities is determined by the macromolecular composition of the individual species which contribute to the assemblage. Recent research suggests that the assemblage composition may change in response to changes in the global climate, which may therefore alter the average nutritional value of the microalgal community. Currently, knowledge of cellular composition of individual species is scarce, largely due to technical challenges associated with measuring the macromolecular composition of individual species from mixed natural assemblages. This project takes advantage of recent developments in Synchrotron-based Fourier Transform Infrared (FTIR) Microspectroscopy, which has the spatial resolution and sensitivity to measure changes in the macromolecular composition of individual cells. The spectroscopic data is complemented by multivariate statistical analysis techniques which enable modelling of changes in macromolecular composition and classification of cells by their taxon and physiology. The project encompasses both laboratory cultures and samples of natural phytoplankton from the Southern Ocean which have been collected from near the Kerguelen archipelago during the recent KEOPS2 expedition.
Olivia's project is a collaboration between UTS and Monash University, with contributions from Dr Leanne Armand at Macquarie University. The project is due for completion mid-2013.
(1) Investigate mechanisms by which climate change may affect microalgal nutritional value (lipid, protein and carbohydrate ratios) and their carbon productivity.
(2) Examine factors controlling microalgal assemblage composition and which species becomes dominant in the meltwater bloom
(3) Develop tools for taxonomic classification of cells by their infrared spectra and physiology
Olivia in the News