A comparative analysis of gaseous phase hydration properties of two lichenized fungi: Niebla tigrina (Follman) Rundel & Bowler from Atacama Desert and Umbilicaria antarctica Frey & I. M. Lamb from Robert Island, Southern Shetlands Archipelago, maritime Antarctica

Abstract

Gaseous phase hydration properties for thalli of Niebla tigrina from Atacama Desert, and for Umbilicaria antarctica from Isla Robert, maritime Antarctica, were analyzed using 1H-NMR relaxometry, spectroscopy, and sorption isotherm analysis. The molecular dynamics of residual water was monitored to distinguish the sequential binding very tightly, tightly, and loosely bound water fractions. These two species differ in hydration kinetics faster for Desert N. tigrina [A1 = 0.51(4); t1 = 0.51(5) h, t2 = 15.0(1.9) h; total 0.7 for p/p0 = 100%], compared to Antarctic U. antarctica [A1 = 0.082(6), t1 = 2.4(2) h, t2 = [26.9(2.7)] h, total 0.6 for p/p0 = 100%] from humid polar area. The 1H-NMR measurements distinguish signal from tightly bound water, and two signals from loosely bound water, with different chemical shifts higher for U. antarctica than for N. tigrina. Both lichen species contain different amounts of water-soluble solid fraction. For U. antarctica, the saturation concentration of water soluble solid fraction, cs = 0.55(9), and the dissolution effect is detected at least up to Δm/m0 = 0.7, whereas for N. tigrina with the similar saturation concentration, cs = 053(4), this fraction is detected up to the threshold hydration level equal to ΔM/m0 = 0.3 only.

Low-temperature investigation of residual water bound in free-living Antarctic Prasiola crispa

“…By contrast, water molecules situated in the proximity of the pore walls of the sample have longer correlation times (shorter ) as their rotation is hindered. This is particularly evident in Antarctic lichens, as well as in lyophilized photosynthetic membranes, where tightly and loosely bound water fractions differing in their relaxation times were found (Harańczyk et al 2012, 2016, 2021, Nowak et al 2018). The decrease in temperature causes the gradual immobilization of water molecules, which form ice crystallites.…”

Roccellinastrum, Cenozosia and Heterodermia: Ecology and phylogeny of fog lichens and their photobionts from the coastal Atacama Desert

“…The Ramalinaceae is the fourth-largest family of lichenized ascomycetes and their fruticose genera were recently updated and now support the four genera Ramalina (sub-cosmopolitan), Namibialina (endemic to South West Africa), Niebla and Vermilacinia (endemic to the New World) ( Spjut et al 2020 ). Most of these genera occur in fog-influenced, arid desert environments and also members of the genus Niebla were frequently reported from the coastal Atacama Desert ( Rundel 1978 ; Harańczyk et al 2021 ). However, already in 1981, Bowler noted that the species Cenozosia inanis - the type of the genus Cenozosia - described as an endemic species from the Atacama Desert resembles Niebla ceruchis (Bowler, 1981), probably caused by a similar macroscopic thallus structure.…”