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

Rutger de Wit (1) , Pascale Gautret (2) , Yvan Bettarel (1) , Cécile Roques (1) , Christian Marlière (3) , Michel Ramonda (4) , Thuy Nguyen Thanh (5) , Huy Tran Quang (5) , Thierry Bouvier (1)

1 Ecosym - Ecologie des systèmes marins côtiers
2 ISTO - Institut des Sciences de la Terre d'Orléans - UMR7327
3 ISMO - Institut des Sciences Moléculaires d'Orsay
4 UM - Université de Montpellier
5 Nanobiomedicine group

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.

Domaines: Planète et Univers [physics]; Interfaces continentales, environnement

Rutger de Wit, Pascale Gautret, Yvan Bettarel, Cécile Roques, Christian Marlière, et al.. Viruses Occur Incorporated in Biogenic High-Mg Calcite from Hypersaline Microbial Mats. PLoS ONE, 2015, pp.1-19. ⟨10.1371/journal.pone.0130552⟩. ⟨insu-01171048⟩