Production and temperature sensitivity of long chain alkenones in the cultured haptophyte Pseudoisochrysis paradoxa

Theroux, S., Toney, J. , Amaral-Zettler, L. and Huang, Y. (2013) Production and temperature sensitivity of long chain alkenones in the cultured haptophyte Pseudoisochrysis paradoxa. Organic Geochemistry, 62, pp. 68-73. (doi: 10.1016/j.orggeochem.2013.07.006)

Abstract

The alkenone unsaturation index (U₃₇^K or U₃₇^K′) serves as a critical tool for reconstructing temperature in marine environments. Lacustrine haptophyte algae are genetically distinct from their ubiquitous and well studied marine counterparts, and the unknown species-specific genetic imprints on long chain alkenone production by lacustrine species have hindered the widespread application of the U37^K temperature proxy to lake sediment records. The haptophyte Pseudoisochrysis paradoxa produces alkenones but its U37^K calibration has never been determined. It has an alkenone fingerprint abundant in tetraunsaturated alkenones, a hallmark of lacustrine environments. We present here the first calibration of the U37^K index to temperature for a culture of P. paradoxa. We found that the U37^K index accurately captured the alkenone response to temperature whereas the U37^K′ index failed to do so, with U37^K′ values below 0.08 projecting to two different temperature values. Our results add a fifth species-specific U37^K calibration and provide another line of evidence that different haptophyte species require different U37^K calibrations. The findings also highlight the necessary inclusion of the C_37:4 alkenone when reconstructing temperatures from P. paradoxa-derived alkenone records.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Toney, Professor Jaime
• Authors: Theroux, S., Toney, J., Amaral-Zettler, L., and Huang, Y.
• Subjects: Q Science > Q Science (General); Q Science > QD Chemistry; Q Science > QE Geology; Q Science > QK Botany
• College/School: College of Science and Engineering > School of Geographical and Earth Sciences
• Research Group: BECS Biomarkers for Environmental and Climate Science
• Journal Name: Organic Geochemistry
• Publisher: Pergamon (Elsevier)
• ISSN: 0146-6380
• ISSN (Online): 1873-5290
• Copyright Holders: Copyright © 2013 The Authors
• First Published: First published online in Organic Chemistry
• Publisher Policy: Reproduced in accordance with the copyright policy of the publisher