The York Research Database

Abstract The lipid cores from Ignisphaera aggregans, a
hyperthermophilic Crenarchaeon recently isolated from
New Zealand hot springs, have been profiled by liquid chromatography–
tandem mass spectrometry. The distribution
revealed includes relatively high proportions of monoalkyl
(also known as H-shaped) tetraether cores which have previously
been implicated as kingdom-specific biomarkers for the
Euryarchaeota. Such high expression ofmonoalkyl tetraether
lipids is unusual in the archaeal domain and may indicate that
formation of these components is an adaptive mechanism
that allows I. aggregans to regulate membrane behaviour at
high temperatures. The observed dialkyl tetraether and
monoalkyl tetraether lipid distributions are similar but not
fully concordant, showing differences in the average number
of incorporated rings. The similarity supports a biosynthetic
route to the ring-containing dialkyl and monoalkyl tetraether
lipids via a dialkyl tetraether core containing zero rings, or a
closely related structural relative, as an intermediate. Currently,
however, the precise nature of the biosynthetic route to
these lipids cannot be deduced.