Community Structure of Subsurface Biofilms in the Thermal Sulfidic Caves of Acquasanta Terme, Italy


Material Information

Community Structure of Subsurface Biofilms in the Thermal Sulfidic Caves of Acquasanta Terme, Italy
Series Title:
Applied and Environmental Microbiology
Jones, D. S.
Tobler, D. J.
Schaperdoth, I.
Mainiero, M.
Macalady, J. L.
Publication Date:


Subjects / Keywords:
Community Structure ( local )
Subsurface Biofilms ( local )
Sulfidic Caves ( local )
Acquasanta Terma, Italy ( local )
serial ( sobekcm )


We performed a microbial community analysis of biofilms inhabiting thermal (35 to 50°C) waters more than 60 m below the ground surface near Acquasanta Terme, Italy. The groundwater hosting the biofilms has 400 to 830 μM sulfide, <10 μM O2, pH of 6.3 to 6.7, and specific conductivity of 8,500 to 10,500 μS/cm. Based on the results of 16S rRNA gene cloning and fluorescent in situ hybridization (FISH), the biofilms have low species richness, and lithoautotrophic (or possibly mixotrophic) Gamma- and Epsilonproteobacteria are the principle biofilm architects. Deltaproteobacteria sequences retrieved from the biofilms have <90% 16S rRNA similarity to their closest relatives in public databases and may represent novel sulfate-reducing bacteria. The Acquasanta biofilms share few species in common with Frasassi cave biofilms (13°C, 80 km distant) but have a similar community structure, with representatives in the same major clades. The ecological success of Sulfurovumales-group Epsilonproteobacteria in the Acquasanta biofilms is consistent with previous observations of their dominance in sulfidic cave waters with turbulent water flow and high dissolved sulfide/oxygen ratios. Despite rapid progress in the past decade, the deep subsurface remains one of the least explored microbial habitats on earth. Recent studies illustrate the presence of significant spatial heterogeneity (13, 53) and the strong influence of mineralogy and fluid flow on subsurface microbial biodiversity (9, 16, 31, 61). Data obtained by drilling are complemented by an increasing number of studies that exploit subsurface passages navigable by humans (17). These subsurface passages include caves (14, 46) and mines (22, 32, 47, 52, 57). Approximately 10% of known caves (49) and perhaps more (33) are formed where reduced, sulfidic groundwaters interact with oxidized water descending from surface environments. Limestone dissolution in these groundwater mixing zones results in deep caves that receive few organic inputs from the surface. Due to the presence of b
Original Version:
Applied and Environmental Microbiology, Vol. 76, no. 17 (2010-08-24).

Record Information

Source Institution:
University of South Florida Library
Holding Location:
University of South Florida
Rights Management:
This object is protected by copyright, and is made available here for research and educational purposes. Permission to reuse, publish, or reproduce the object beyond the bounds of Fair Use or other exemptions to copyright law must be obtained from the copyright holder.

USFLDC Membership

University of South Florida
Karst Information Portal

Postcard Information



Download Options


No images or PDF downloads are available for this resource.

Cite this item close


Cras ut cursus ante, a fringilla nunc. Mauris lorem nunc, cursus sit amet enim ac, vehicula vestibulum mi. Mauris viverra nisl vel enim faucibus porta. Praesent sit amet ornare diam, non finibus nulla.


Cras efficitur magna et sapien varius, luctus ullamcorper dolor convallis. Orci varius natoque penatibus et magnis dis parturient montes, nascetur ridiculus mus. Fusce sit amet justo ut erat laoreet congue sed a ante.


Phasellus ornare in augue eu imperdiet. Donec malesuada sapien ante, at vehicula orci tempor molestie. Proin vitae urna elit. Pellentesque vitae nisi et diam euismod malesuada aliquet non erat.


Nunc fringilla dolor ut dictum placerat. Proin ac neque rutrum, consectetur ligula id, laoreet ligula. Nulla lorem massa, consectetur vitae consequat in, lobortis at dolor. Nunc sed leo odio.