Carotenoids dispersed in gypsum rock as a result of algae adaptation to the extreme conditions of the Atacama Desert.

The high-altitude pre-Andean region of the Atacama Desert is characterized by its stark volcanic rock formations and unique hydrothermal gypsum outcrops (gypcrete) that it hosts. This study delves into the biomolecular composition of the endolithic phototrophic microbes that thrive within these gypcretes. Using advanced Raman spectroscopy techniques, including Raman imaging (complemented by microscopic and 3D microscopic observations), herein we unveil new insights into the adaptive strategies of these gypsum-inhabiting algae.

Microbial colonization of gypsum: from the fossil record to the present day.

Microorganisms inhabiting gypsum have been observed in environments that differ greatly in water availability. Gypsum colonized by microorganisms, including cyanobacteria, eukaryotic algae, and diverse heterotrophic communities, occurs in hot, arid or even hyperarid environments, in cold environments of the Antarctic and Arctic zones, and in saline and hypersaline lakes and ponds where gypsum precipitates. Fossilized microbial remnants preserved in gypsum were also reported.

Sea spray allows for the growth of subaerial microbialites at the driest desert on Earth.

Due to its extreme conditions, microbial life in the Atacama Desert is known to survive in well-protected micro-habitats (hypolithic, endolithic, etc.), but rarely directly exposed to the environment, that is, epilithic habitats. Here we report a unique site, La Portada, a cliff confronting the Pacific Ocean in the Coastal Range of this desert, in which the constant input of water provided by the sea spray allows for the growth of a black-colored epilithic subaerial microbial ecosystem.

Innovative approaches to accurately assess the effectiveness of biocide-based treatments to fight biodeterioration of Cultural Heritage monuments.

The development of diagnostic methods to accurately assess the effects of treatments on lithobiont colonization remains a challenge for the conservation of Cultural Heritage monuments. In this study, we tested the efficacy of biocide-based treatments on microbial colonization of a dolostone quarry, in the short and long-term, using a dual analytical strategy. We applied a metabarcoding approach to characterize fungal and bacterial communities over time, integrated with microscopy techniques to analyze the interactions of microorganisms with the substrate and evaluate the effectiveness.