Abstract
Abstract. Viruses have been acknowledged as being important components of the marine system for the past 2 decades, but their role in the functioning of the geochemical cycle has not been thoroughly elucidated to date. Virus-induced rupturing of cyanobacteria is theoretically capable of releasing intracellular bicarbonate and inducing the homogeneous nucleation of calcium carbonate; however, experiment-based support for virus-induced calcification is lacking. In this laboratory study, both water carbonate chemistry and precipitates were monitored during the viral infection and lysis of host cells. Our results show that viral lysis of cyanobacteria can influence the carbonate equilibrium system remarkably and promotes the formation and precipitation of carbonate minerals. Amorphous calcium carbonate (ACC) and aragonite were evident in the lysate, compared with the Mg(OH)2 (brucite in this paper) precipitate in noninfected cultures, implying that a different precipitation process had occurred. Based on the carbonate chemistry change and microstructure of the precipitation, we propose that viral lysis of cyanobacteria can construct a calcification environment where carbonate is the dominant inorganic carbon species. Numerous virus particles available in lysate may coprecipitate with the calcium carbonate. The experimental results presented in this study demonstrate both the pathway and the outcome with respect to how viruses influence the mineralization of carbonate minerals. It is suggested that viral calcification offers new perspectives on mechanisms of CaCO3 biomineralization and may play a crucial role within the Earth system.
Highlights
Cyanobacteria, which are ubiquitously abundant organisms and play important roles in most aquatic environments, are generally known to influence CaCO3 precipitation by taking up inorganic carbon via photosynthesis (Obst et al, 2009b; Planavsky et al, 2009; Yang et al, 2016; Kamennaya et al, 2012; Kranz et al, 2010; Semesi et al, 2009; Riding, 2011, 2012; Merz-Preiß, 2000)
By the time cells were lysed, the white precipitation phase had emerged in Group A (Fig. 1b, d)
Cell growth was monitored over the course of 20 days by counting the autofluorescence of cyanobacteria
Summary
Cyanobacteria, which are ubiquitously abundant organisms and play important roles in most aquatic environments, are generally known to influence CaCO3 precipitation by taking up inorganic carbon via photosynthesis (Obst et al, 2009b; Planavsky et al, 2009; Yang et al, 2016; Kamennaya et al, 2012; Kranz et al, 2010; Semesi et al, 2009; Riding, 2011, 2012; Merz-Preiß, 2000). Calcium carbonate formation mediated by cyanobacteria is of great importance in sedimentary deposits, the mechanisms involved are still controversial. The precipitation of CaCO3 by cyanobacteria has been invariably considered a noncontrolled process, promoted by either photosynthetic uptake of inorganic carbon, which raises the pH adjacent to cyanobacterial cells (Riding, 2006), or induced by cell-surface properties for the nucleation of CaCO3 minerals (Obst et al, 2009b). Diverse cyanobacterial taxa have recently been shown to form amorphous calcium carbonate (ACC) minerals intracellularly, which have diameters of several hundreds of nanometers (Couradeau et al, 2012; Benzerara et al, 2014). New pathways, in which some biological processes alter the carbonate system, are important to evaluate
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
