Journal article

Diatoms response to salinity changes: investigations using single pulse and cross polarisation magic angle spinning Si-29 NMR spectra

MR Johnston, JR Gascooke, AV Ellis, SC Leterme



Diatoms Thalassiosira pseudonana and Chaetoceros muelleri (Bacillariophyceae) were cultured at three different salinities (26, 36 and 46 practical salinity units (PSU)) and their silica content examined using natural abundance 29Si magic angle spinning (MAS) nuclear magnetic resonance (NMR) spectroscopy. The samples were investigated using both single pulse (SP) and cross-polarisation (CP) MAS experiments. In addition, samples of T. pseudonana were examined using variable contact time CP MAS experiments allowing the dynamics (TSiH and T1rρH) of CP to be determined. Comparison of SP and CP results revealed a change to a less condensed silica state when diatoms were cultured at salinities away..

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University of Melbourne Researchers


Awarded by ARC Discovery Project

Awarded by ARC

Funding Acknowledgements

The authors would like to thank Satish Dogra, John Hayles and Sian La Vars for culturing the diatoms used in this study. JRG acknowledges financial support from the Australian National Fabrication Facility (ANFF). The work was supported by an ARC Discovery Project DP110101679. Thanks also to the ARC for a LIEF grant (LE0668489) to purchase 400 NMR spectrometer allowing solid state NMR work and also an upgrade to a 7 mm probe, amplifier and high power preamplifier (LE130100168).