Prokaryotic communities from a lava tube cave in La Palma Island (Spain) are involved in the biogeochemical cycle of major elements

Lava caves differ from karstic in their genesis and mineral composition. Subsurface microbiology of lava tube Canary Islands, a volcanic archipelago the Atlantic Ocean, is largely unknown. We have focused investigation representative cave, Fuente de la Canaria Cave, La Palma Island, Spain, which presents different types speleothems colored microbial mats. Four samples collected this cave were studied using DNA next-generation sequencing field emission scanning electron microscopy for bacterial identification, functional profiling, morphological characterization. The data showed an almost exclusive dominance Bacteria over Archaea . distribution phyla revealed majority abundance Proteobacteria (37–89%), followed by Actinobacteria , Acidobacteria Candidatus Rokubacteria. These four comprised total relative 72–96%. main ecological functions communities chemoheterotrophy, methanotrophy, sulfur nitrogen metabolisms, CO 2 fixation; although other outlined. Genome annotations especially taxon Ga0077536 (about 71% moonmilk) predicted presence genes involved fixation, formaldehyde consumption, microbially-induced carbonate precipitation. detection several putative lineages associated with C, N, S, Fe Mn indicates that Cave basalts are colonized metabolically diverse prokaryotic biogeochemical cycling major elements.