Influences of Electron Donor, Bicarbonate, and Sulfate on Bioreduction Processes and Manganese/Copper Redistributions among Minerals in a Water-Saturated Sediment

Biological Reduction of Hydrogel-Encapsulated Fe(III) by Shewanella oneidensis MR-1: Incubation Experiment and Kinetic Modeling

“…The formation of secondary iron minerals, such as siderite and vivianite, also results in the removal of Fe(II) ions from the aqueous phase [22]. In our other experiment, the concentration of Fe(II) ion was also limited, whereas the iron phase in adsorbed forms and/or precipitates could be detected in the soil sample [11]. By contrast, the concentration of Fe(II) ion quickly increased to over 2 mg L −1 upon treatment with 6.6 g L −1…”

“…The suspension was centrifuged at 10,000 rpm for 2 min. The concentration of Fe(II) ion in the supernatant was measured by phenanthroline spectrophotometry [11].…”

“…The growth and activity of metal-reducing microorganisms are affected by the interaction of environmental factors, including iron mineral type and content, pH, and carbon substrate concentration -factors that cause variations in the performance of biological iron reduction [10,11]. Previous research found that the extent of the reductive dissolution of highly crystalline iron minerals is lower than the reduction of amorphous and poorly crystalline iron oxyhydroxides [10].…”

Effects of Microbial Iron Reduction and Oxidation on the Immobilization and Mobilization of Copper in Synthesized Fe(III) Minerals and Fe-Rich Soils

“…The major soil minerals in the clay fraction of the surface sediments were found to be kaolinite and quartz, with Fe (hydr)oxides presented as coatings. Additional details regarding the elemental composition and particle distribution can be found in our previous study [36]. The obtained sediments were cultivated in 120 ml serum bottles with 80 ml of the medium under anaerobic conditions.…”

“…PCR was performed in 25 µl PCR mixtures that included 12.5 µl of 2× Tag PCR MasterMix (Tiangen Biotech Co., Ltd., Beijing, China), 0.5 µl of each primer (20 pmol), 1 µl of genomic DNA (~50 ng), and 10.5 µl of sterile DNA-free water. The PCR temperature program was initiated with denaturing at 94°C for 5 min, followed by 10 cycles at 94°C for 30 sec, 65°C for 45 sec, and 72°C for 1 min; 20 cycles at 94°C for 30 sec, 55°C for 45 sec, and 72°C for 1 min; and a final extension of 72°C for 7 min, using a PCR Thermo Cycler (Model JC-96, China) [36].…”