Osmotic adaptation of the halophilic fungus Hortaea werneckii: role of osmolytes and melanization.

This study was intended to determine the osmoadaptation strategy of Hortaea werneckii, an extremely salt-tolerant melanized ascomycetous fungus that can grow at 0-5.1 M NaCl. It has been shown previously that glycerol is the major compatible solute in actively growing H.

Structure of euhalothece-362, a novel red-shifted mycosporine-like amino acid, from a halophilic cyanobacterium (Euhalothece sp.).

The unicellular cyanobacterium Euhalothece sp. strain LK-1, isolated from a gypsum crust on the bottom of a hypersaline saltern pond in Eilat, Israel, contains high concentrations of two mycosporine-like amino acids with maximum absorbance at 331 and 362 nm when grown at high light intensities. The 331 nm-absorbing compound has previously been identified as mycosporine-2-glycine.

A broadly applicable method for extraction and characterization of mycosporines and mycosporine-like amino acids of terrestrial, marine and freshwater origin.

A universal method allowing simultaneous extraction and analysis of diverse ultraviolet-B-absorbing compounds belonging to mycosporines and mycosporine-like amino acids (MAAs) is presented. Mycosporines and MAAs are found both in prokaryotes and eukaryotes and possess photoprotective properties. Our method was successfully tested by screening 31 cyanobacterial, 11 actinomycete and 45 fungal strains for their mycosporine and MAA content.

Mycosporine-glutamicol-glucoside: a natural UV-absorbing secondary metabolite of rock-inhabiting microcolonial fungi.

Microcolonial ascomycetes are known to inhabit bare rock surfaces in cold and hot deserts and thus are habitually exposed to high levels of solar radiation. Several of these stress-tolerant fungal isolates, cultivated in the laboratory under daylight illumination, were studied for the presence of effective UV-radiation protection substances. Liquid chromatography/mass spectrometry (LC/MS) and liquid chromatography/tandem mass spectrometry (LC/MS/MS) analyses allowed for efficient separation and structure clarification of two mycosporines.

Rock surfaces as life indicators: new ways to demonstrate life and traces of former life.

Life and its former traces can only be detected from space when they are abundant and exposed to the planetary atmosphere at the moment of investigation by orbiters. Exposed rock surfaces present a multifractal labyrinth of niches for microbial life. Based upon our studies of highly stress-resistant microcolonial fungi of stone monument and desert rock surfaces, we propose that microbial biofilms that develop and become preserved on rock surfaces can be identified remotely by the following characteristics: (1) the existence of spectroscopically identifiable compounds that display unique adsorption, diffraction, and reflection patterns characteristic of biogenerated organic compounds (e.