Macquarie University
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Effects of temperature on macromolecular composition of the Antarctic diatom, Corethron pennatum

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posted on 2022-03-28, 16:00 authored by Peta L. Vine
Southern Ocean temperatures are rising due to climate change. Increasing temperature can alter diatom physiology and survival, subsequently affecting primary productivity and distributions. Diatoms are important primary producers and their composition mediates energy and nutrient transfer to higher trophic levels. Diatom physiology and macromolecular composition are useful indicators for demonstrating and modelling microalgal response to climate change. Using pulse amplitude modulated fluorometry and Attenuated Total Reflectance - Fourier Transform Infrared (ATR-FTIR) spectroscopy, I characterised the physiological response and macromolecular composition of the Antarctic diatom, Corethron pennatum cultured at 0 °C to 5°C. The ATR-FTIR generated data were used to create spectroscopy-based predictive models. The photosynthetic capacity of C. pennatum decreased as temperatures increased, while all cultures eventually failed at 5 °C. As growth temperature increased, unsaturated fatty acid concentrations generally increased, and protein levels decreased slightly. Lipid levels were lowest at the coldest growth temperatures. These findings, particularly the unusual lipid unsaturation at the highest temperatures, show that C. pennatum physiology may differ from many diatoms. Additionally, the model demonstrated a high predictive power (R2 = 0.98), showing that macromolecular composition of C. pennatum is a useful intracellular marker that could be used to model microalgal response to climate change.



Bibliography: pages 45-53 Thesis by publication.

Awarding Institution

Macquarie University

Degree Type

Thesis MRes


MRes, Macquarie University, Faculty of Science and Engineering, Department of Biological Sciences

Department, Centre or School

Department of Biological Sciences

Year of Award


Principal Supervisor

Grant Hose

Additional Supervisor 1

Philip Heraud

Additional Supervisor 2

John Beardall


Copyright Peta L. Vine 2018. Copyright disclaimer:




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