Open AccessTemperature‐dependent variation in the distribution of tetraether membrane lipids of marine Crenarchaeota: Implications for TEX 86 paleothermometry
Author(s) -
Wuchter Cornelia,
Schouten Stefan,
Coolen Marco J. L.,
Sinninghe Damsté Jaap S.
Publication year - 2004
Publication title -
paleoceanography
Language(s) - English
Resource type - Journals
eISSN - 1944-9186
pISSN - 0883-8305
DOI - 10.1029/2004pa001041
Subject(s) - crenarchaeota , cyclopentane , mesocosm , chemistry , incubation , proxy (statistics) , environmental chemistry , biochemistry , stereochemistry , organic chemistry , mathematics , archaea , statistics , nutrient , gene
Recently, a new geochemical temperature proxy, the TEX 86 , was introduced. This proxy is based on the number of cyclopentane moieties in the glycerol dialkyl glycerol tetraethers (GDGTs) of the membrane lipids of marine Crenarchaeota, which changes as a response to temperature. However, until now, only sediment data have been used to establish this proxy, and experimental work is missing. We performed mesocosm studies with marine Crenarchaeota incubated at temperatures ranging from 5 to 35°C and salinities of 27 and 35‰ to test the validity of the TEX 86 proxy. Growth of marine Crenarchaeota in these mesocosms was evident from the substantial increase in the concentration of marine Crenarchaeotal membrane lipids with amounts up to 3400 ng/L. With increasing temperature, an increase in the number of cyclopentane moieties in the crenarchaeotal membrane lipids was observed. Different salinities did not show any effect on the GDGT distribution. The TEX 86 showed a significant linear correlation to incubation temperature: TEX 86 = 0.015 × T + 0.10 (r 2 = 0.79). This equation has a similar slope to the correlation obtained from core tops but differs in the intersection (TEX 86 = 0.015 × T + 0.28, r 2 = 0.92). This difference is mainly determined by the smaller amount of the regioisomer of crenarchaeol in the incubation series compared to core top samples. These incubation experiments indicates that water temperature is indeed the major controlling factor for the membrane distribution of marine Crenarchaeota and confirms that the TEX 86 proxy depends on a physiological response to regulate membrane fluidity.