Dolomite Formation Facilitated by Three Halophilic Archaea

Duan Yong; Yao Yanchen; Qiu Xuan; Wang Hongmei

doi:10.3799/dqkx.2017.029

Abstract：The dolomite formation problem has been puzzling geologists for a long time.Recently, microbial mediation is becoming one leading theory for dolomite formation, though many details still remain poorly understood.The exclusive occurrence of modern dolomite in saline environments leads to the investigation of the role of halophiles in dolomite formation.In this study, we focus on the effect of salinity and cell concentrations on dolomite mineralization with three halophilic archaea, Natrinema sp.J7-1, Natrinema sp.J7-3 and Natrinema sp.LJ7.These halophilic archaea were collected and subject to the mineral phase identification, morphology observation and element analysis via X-ray Diffraction (XRD) and Scanning Electronic Microscopy equipped with Energy Dispersive Spectrum (EDS).Results confirm that all the strains used are capable of facilitating the dolomite formation under higher salinity conditions, and the yields of dolomite increase with cell concentration.Morphologically, dolomite is of the shape of sphere, dumb-bell, cauliflower and conglobulation.It is proposed that high salinity and high cell density will result in the more carboxyl groups on cell surface which can serve as nucleation sites for dolomite formation, which is favorable for dolomite formation.The results offer more details about microbial role in dolomite formation and enhance our understanding about the mechanism.