Open AccessThe biogeochemical role of A ctinobacteria in A ltamira C ave, S pain
Author(s) -
Cuezva Soledad,
FernandezCortes Angel,
Porca Estefania,
Pašić Lejla,
Jurado Valme,
HernandezMarine Mariona,
SerranoOrtiz Penelope,
Hermosin Bernardo,
Cañaveras Juan Carlos,
SanchezMoral Sergio,
SaizJimenez Cesareo
Publication year - 2012
Publication title -
fems microbiology ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.377
H-Index - 155
eISSN - 1574-6941
pISSN - 0168-6496
DOI - 10.1111/j.1574-6941.2012.01391.x
Subject(s) - spots , cave , biology , actinobacteria , black spot , bacteria , scanning electron microscope , transmission electron microscopy , paleontology , botany , ecology , materials science , 16s ribosomal rna , nanotechnology , horticulture , composite material
The walls and ceiling of A ltamira C ave, northern S pain, are coated with different coloured spots (yellow, white and grey). Electron microscopy revealed that the grey spots are composed of bacteria and bioinduced CaCO 3 crystals. The morphology of the spots revealed a dense network of microorganisms organized in well‐defined radial and dendritic divergent branches from the central area towards the exterior of the spot, which is coated with overlying spheroidal elements of CaCO 3 and CaCO 3 nest‐like aggregates. Molecular analysis indicated that the grey spots were mainly formed by an unrecognized species of the genus A ctinobacteria . CO 2 efflux measurements in rocks heavily covered by grey spots confirmed that bacteria‐forming spots promoted uptake of the gas, which is abundant in the cave. The bacteria can use the captured CO 2 to dissolve the rock and subsequently generate crystals of CaCO 3 in periods of lower humidity and/or CO 2 . A tentative model for the formation of these grey spots, supported by scanning electron microscopy and transmission electron microscopy data, is proposed.