TY - JOUR
T1 - Biosignatures and bacterial diversity in hydrothermal deposits of Solfatara Crater, Italy
AU - Glamoclija, Mihaela
AU - Garrel, Laurence
AU - Berthon, Jonathan
AU - López-García, Purificación
N1 - Funding Information:
We thank A. Baliva for XRD analysis, A. Traini for the possibility of using SEM, and L. Tonucci for NMR analysis. The FT-IR analysis was done by G. de Matia, “Parco Scientifico e Tecnologico d’Abruzzo,” Chieti. Special thanks are given to Prof. R. Barbieri, University of Bologna, for his hospitality and useful advisory to M. Glamoclija during two months. We want to thank A. P. Rossi, IRSPS, for help during fieldwork, as well as D. Moreira for assistance during purification of samples for biological purposes. A special thanks to Vulcano Solfatara s.r.l. for the hospitality and interest in this research. This work was funded by the Agenzia Spaziale Italiana (ASI), the exobiology program, and the French CNRS-INSUE program Géomicrobiologie des environnements extrêmes (GEOMEX).
PY - 2004/12
Y1 - 2004/12
N2 - We have combined mineralogy, organic geochemistry and molecular microbiology to study hydrothermal deposits from Solfatara Crater, a geologically young volcanic formation (∼4,000 years old) displaying hot (45-95°C) and acidic (pH 1.7) mud pools and fumaroles. The search for inorganic (mineral) biosignatures revealed the presence of delicate structures, most likely mineralized extracellular polymers (EPSs), and the presence of potential biologically induced minerals: sulfides, sulfates (barite and alunite), elemental sulfur, and iron oxides. Geochemical analyses revealed a low total organic carbon content, 0.13 to 0.53%, displaying δ13C values from -17.09 to -27.39‰, and total nitrogen contents from 0.03 to 0.12%, which are characteristic of hydrothermal systems and suggest the presence of autotrophic carbon fixation. Lipid biomarker analysis showed the presence of hopanoids and linear alkanes, and the absence of detectable steroids, implying the occurrence of bacteria in our samples. We constructed 16S rRNA gene libraries from the environmental samples. Most environmental sequences obtained were affiliated to the Alpha-and Betaproteobacteria (Hydrogenophilus-like), the Acidobacteria, and to a lesser extent, the Gammaproteobacteria and Actinobacteria. When known, the closest cultivated relatives were often thermophilic or thermotolerant bacteria oxidizing iron, hydrogen, or methane/methanol, suggesting an important microbial contribution to the formation of biominerals.
AB - We have combined mineralogy, organic geochemistry and molecular microbiology to study hydrothermal deposits from Solfatara Crater, a geologically young volcanic formation (∼4,000 years old) displaying hot (45-95°C) and acidic (pH 1.7) mud pools and fumaroles. The search for inorganic (mineral) biosignatures revealed the presence of delicate structures, most likely mineralized extracellular polymers (EPSs), and the presence of potential biologically induced minerals: sulfides, sulfates (barite and alunite), elemental sulfur, and iron oxides. Geochemical analyses revealed a low total organic carbon content, 0.13 to 0.53%, displaying δ13C values from -17.09 to -27.39‰, and total nitrogen contents from 0.03 to 0.12%, which are characteristic of hydrothermal systems and suggest the presence of autotrophic carbon fixation. Lipid biomarker analysis showed the presence of hopanoids and linear alkanes, and the absence of detectable steroids, implying the occurrence of bacteria in our samples. We constructed 16S rRNA gene libraries from the environmental samples. Most environmental sequences obtained were affiliated to the Alpha-and Betaproteobacteria (Hydrogenophilus-like), the Acidobacteria, and to a lesser extent, the Gammaproteobacteria and Actinobacteria. When known, the closest cultivated relatives were often thermophilic or thermotolerant bacteria oxidizing iron, hydrogen, or methane/methanol, suggesting an important microbial contribution to the formation of biominerals.
KW - 16S rRNA
KW - Bacterial diversity
KW - Biosignatures
KW - Hydrothermal
KW - Solfatara Crater
KW - Thermoacidophile
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U2 - 10.1080/01490450490888235
DO - 10.1080/01490450490888235
M3 - Article
AN - SCOPUS:11144317346
SN - 0149-0451
VL - 21
SP - 529
EP - 541
JO - Geomicrobiology Journal
JF - Geomicrobiology Journal
IS - 8
ER -