| Summary: | 碩士 === 國立屏東科技大學 === 環境工程與科學系所 === 106 === Serpentinites from eastern Taiwan is a kind of ultrabasics, this derived soil is characterized by heavy metals of high concentrations like Ni, Cr, Fe and Mn, which can over the soil pollution control standards (SPCS) of Taiwan. Serpentinitic soil has the potential to oxidize Cr(III), surmise that was oxidized by biogenic Mn oxides (bio-MnOx) from manganese oxidizing bacteria (MnOB). Bio-MnOx are the only known natural oxidants of Cr(III), and consequently could control the fate of Cr in the environment. We compared the bacterial community of serpentinitic soil and serpentinitic soil culture enriched by Mn(II) using pyrosequencing. MnOB was isolated from serpentinitic soil of eastern Taiwan and the potential of Cr(III) by Bio-MnOx was examined. We identified eight strains of MnOB by 16S rRNA. One of the strains, Massilia sp. Mn16-1_5, could be cultured in manganese carbonate medium and produced black bio-MnOx. The maximum oxidation potential of the bio-MnOx in oxidizing Cr(III) to Cr(IV) was 4.8 mmol Cr(Ⅵ)/g MnO2 at time of the 121st hour and in pH 3.2. The SEM image and XRD analysis of the bio-MnOx shows the irregular shape, and the poor crystallinity. The biogenic Mn oxides has the potential to oxidize Cr(III) that might involve in the biogeochemical cycle.
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