Page 79 - 2017地大报告电子书

环境学院发展报告

DS52

作 者 : Qiu Xuan; Wang Hongmei*; Yao Yanchen; Yong Duan
EARTH AND PLANETARY SCIENCE LETTERS 卷 : 472 页 : 197-205 出版年 : AUG

15 2017
摘要 :Although most modern dolomites occur in hypersaline environments, the effects

of elevated salinity on the microbial mediation of dolomiteprecipitation have not been
fully evaluated. Here we report results of dolomite precipitation in association with a batch

culture of Haloferax volcanii DS52, a halophilic archaeon, under various salinities (from
120 parts per thousand to 360 parts per thousand) and the impact of salinity on microbe

-mediateddolomite formation. The mineral phases, morphology and atomic arrangement of
the precipitates were analyzed by XRD, SEM and TEM, respectively. The amount of amino

acids on the archaeal cell surface was quantified by HPLC/MS. The XRD analysis indicated
that disordered dolomite formed successfully with the facilitation of cells harvested from

cultures with relatively high salinities (200 parts per thousand and 280 parts per thousand) but
was not observed in association with cells harvested from cultures with lower salinity (120

parts per thousand) or the lysates of cells harvested from extremely high salinity (360 parts per
thousand). The TEM analysis demonstrated that the crystals from cultures with a salinity of

200 parts per thousand closely matched that of dolomite. Importantly, we found that more
carboxyl groups were presented on the

cell surface under high salinity conditions
to resist the high osmotic pressure,

which may result in the subsequent
promotion of dolomite formation. Our

finding suggests a link between variations
in the hydro -chemical conditions

and the formation of dolomite via
microbial metabolic activity and

enhances our understanding about the mechanism of microbially mediated dolomite formation
under high salinity conditions. (C) 2017 Elsevier B.V. All rights reserved.

论文链接：https://doi.org/10.1016/j.epsl.2017.05.018

11.Sulfate enhances the dissimilatory arsenate-respiring prokaryotes-mediated
mobilization, reduction and release of insoluble arsenic and iron from the arsenic-richs

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