Viruses Occur Incorporated in Biogenic High-Mg Calcite from Hypersaline Microbial Mats

• Published in: PloS one 2015-06, Vol.10 (6), p.e0130552-19
• Main Authors: De Wit, Rutger, Gautret, Pascale, Bettarel, Yvan, Roques, Cécile, Marlière, Christian, Ramonda, Michel, Nguyen Thanh, Thuy, Tran Quang, Huy, Bouvier, Thierry
• Format: Article
• Language: English
• Subjects: Acids; Analysis; Atomic force microscopy; Bacteria; Biodiversity; Calcification; Calcite; Calcite crystals; Calcium Carbonate - chemistry; Carbonates; Chaetoceros; Continental interfaces, environment; Deoxyribonucleic acid; DNA; Epidemiology; Exploitation; Laboratories; Mats; Microbial mats; Microorganisms; Microscopy; Morphology; Nanocrystals; Nucleic acids; Phosphorus; Prokaryotes; Ribonucleic acid; RNA; Salinity; Sciences of the Universe; Sediments; Spectrometry, X-Ray Emission; Virology; Viruses; Viruses - chemistry; X ray spectrometers
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0130552

Using three different microscopy techniques (epifluorescence, electronic and atomic force microscopy), we showed that high-Mg calcite grains in calcifying microbial mats from the hypersaline lake "La Salada de Chiprana", Spain, contain viruses with a diameter of 50-80 nm. Energy-dispersive X-ray spectrometer analysis revealed that they contain nitrogen and phosphorus in a molar ratio of ~9, which is typical for viruses. Nucleic acid staining revealed that they contain DNA or RNA. As characteristic for hypersaline environments, the concentrations of free and attached viruses were high (>10(10) viruses per g of mat). In addition, we showed that acid treatment (dissolution of calcite) resulted in release of viruses into suspension and estimated that there were ~15 × 10(9) viruses per g of calcite. We suggest that virus-mineral interactions are one of the possible ways for the formation of nano-sized structures often described as "nanobacteria" and that viruses may play a role in initiating calcification.