The Experts below are selected from a list of 13683 Experts worldwide ranked by ideXlab platform
Yongheng Huang - One of the best experts on this subject based on the ideXlab platform.
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kinetics and mechanism of selenite reduction by zero valent iron under Anaerobic Condition activated and enhanced by dissolved fe ii
Science of The Total Environment, 2019Co-Authors: Yongheng HuangAbstract:Abstract Batch test was conducted to investigate Se(IV) removal kinetics and mechanism by zero valent iron (ZVI) in presence of Fe(II) under Anaerobic Condition. Dissolved Fe(II) activated and enhanced Se(IV) reduction by ZVI, which also determined the removal efficiency, reduction rate, final corrosion products and their structures. Se(IV) was completely removed at initial Fe(II)/Se(IV) ≥ 1.0, and the specific rate constant significantly increased from 0.6 to 3.44 L h−1 m−2 with the augment of ratio from 1.0 to 1.4. At Fe(II)/Se(IV)
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a novel layered double hydroxide coupled with zero valent iron system for selenate removal under Anaerobic Condition batch and continuous studies
Chemical Engineering Journal, 2019Co-Authors: Yongheng HuangAbstract:Abstract Batch and continuous stirred tank reactor (CSTR) tests were conducted to evaluate Se (VI) removal in a hybridized Fe(II)-Al(III)-Cl− layered double hydroxide/zero valent iron system (Fe-Al-Cl-LDH/ZVI) under Anaerobic Condition. This novel system was created by employing a nitrate-AlCl3 pretreatment method to coat the ZVI grains with an LDH surface and produce discrete LDH suspended solids (SS) with diameter of 475.3 nm through a rapid ZVI-AlCl3-nitrate reaction. In batch test, Se (VI) was quickly removed by Fe-Al-Cl-LDH/ZVI grains through adsorption via electrostatic attraction, anion exchange by releasing 1.7 mM Cl−/mM Se (VI) and Se (VI) reduction to Se (IV), Se (0) and Se (-II) by ZVI. In CSTR test, the Anaerobic Fe-Al-Cl-LDH/ZVI system created a self-sustaining highly-reactive mixture that steadily reduced 2 ppm Se (VI) to below EPA discharge limit (50 ppb) in a single-stage reactor, where 200–300 ppm Cl− and 6.5–20 ppm SO42− coexisted. Externally-supplied FeCl2 and AlCl3 were essential to maintain LDH as the iron corrosion product and thus the high reactivity of ZVI. This study suggests that the Fe-Al-Cl-LDH/ZVI system could overcome ZVI passivation and thus provide an effective platform for Se (VI) and potentially other water contaminants removal.
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kinetics and mechanism of selenite reduction by zero valent iron under Anaerobic Condition activated and enhanced by dissolved fe ii
Science of The Total Environment, 2019Co-Authors: Yongheng HuangAbstract:Batch test was conducted to investigate Se(IV) removal kinetics and mechanism by zero valent iron (ZVI) in presence of Fe(II) under Anaerobic Condition. Dissolved Fe(II) activated and enhanced Se(IV) reduction by ZVI, which also determined the removal efficiency, reduction rate, final corrosion products and their structures. Se(IV) was completely removed at initial Fe(II)/Se(IV) ≥ 1.0, and the specific rate constant significantly increased from 0.6 to 3.44 L h-1 m-2 with the augment of ratio from 1.0 to 1.4. At Fe(II)/Se(IV) < 1.0 (take 0.6 as an example), Raman, XPS, SEM-EDS and XRD results suggested that Se(IV) was reduced to amorphous Se(0) in forms of red suspended solids, amorphous FeSe and crystal maghemite (γ-Fe2O3) coated on ZVI surface. At Fe(II)/Se(IV) ≥ 1.0 (take 1.0 and 1.4 as examples), crystal FeSe and magnetite (Fe3O4) deposits formed on ZVI surface with a core-shell structure. Additionally, final pH increased due to Se(IV) reduction. This study suggested that traditional ZVI passivation problem could be overcome through the addition of excess dissolved Fe(II) under Anaerobic Condition, which also provided an alternative method to produce a reactive ammonia-free Fe3O4/ZVI/Fe(II) system.
Zhenyu Shi - One of the best experts on this subject based on the ideXlab platform.
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experimental evidence for growth advantage and metabolic shift stimulated by photophosphorylation of proteorhodopsin expressed in escherichia coli at Anaerobic Condition
Biotechnology and Bioengineering, 2015Co-Authors: Ying Wang, Zhenyu ShiAbstract:Since solar light energy is the source of all renewable biological energy, the direct usage of light energy by bacterial cell factory has been a very attractive concept, especially using light energy to promote Anaerobic fermentation growth and even recycle low-energy carbon source when energy is the limiting factor. Proteorhodopsin(PR), a light-driven proton pump proven to couple with ATP synthesis when expressed heterogeneously, is an interesting and simple option to enable light usage in engineered strains. However, although it was reported to influence fermentation in some cases, heterogeneous proteorhodopsin expression was never shown to support growth advantage or cause metabolic shift by photophosphorylation so far. Hereby, we presented the first experimental evidence that heterogeneously expressed proteorhodopsin can provide growth advantage and cause ATP-dependent metabolism shift of acetate and lactate changes in Escherichia coli at Anaerobic Condition. Those discoveries suggest further application potential of PR in Anaerobic fermentation where energy is a limiting factor.
Ying Wang - One of the best experts on this subject based on the ideXlab platform.
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adsorption and transformation of thioarsenite at hematite water interface under Anaerobic Condition in the presence of sulfide
Chemosphere, 2019Co-Authors: Ying Wang, Jinru Lin, Shaofeng Wang, Danni Zhang, Fan Xiao, Xin Wang, Yongfeng JiaAbstract:Abstract The adsorption behavior of thioarsenite (TAsIII) on the surface of hematite (α-Fe2O3) is unknown at present. In the present study, we have investigated the transformation and reactions of TAsIII [monothioarsenite (MTAsIII) and dithioarsneite (DTAsIII)] on the surface of α-Fe2O3 in the presence of sulfide at S/As = 1 and 3 by X-ray absorption spectroscopy (XAS) and Raman spectroscopy. The adsorption envelopes reveal that the adsorption of TAsIII on α-Fe2O3 is significantly less than that of arsenite (AsIII) in the pH range from 7 to 11 with the initial As concentration of 25 mg L−1. However, at the initial As concentration of 135 mg L−1, the uptake of TAsIII by α-Fe2O3 is higher at pH 7 but lower at pH 8–11 than that of AsIII. The adsorption isotherms show that the adsorption of As on α-Fe2O3 is largely inhibited by the presence of aqueous sulfide at pH 7 with low As equilibrium concentration ( 40 mg L−1), implying the formation of As-bearing (surface) precipitate. The As and S K-edge XAS as well as Raman spectroscopy confirm the formation of As sulfide precipitate on the surface of α-Fe2O3 in MTAsIII system. It is worth to note that the oxidation of (thio) AsIII occurs on the surface of α-Fe2O3 in DTAsIII system under strictly Anaerobic Conditions. These results shed new light on the understanding of the interfacial behavior of As and point to the potential implication in immobilization and removal of arsenic in sulfidic environment.
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experimental evidence for growth advantage and metabolic shift stimulated by photophosphorylation of proteorhodopsin expressed in escherichia coli at Anaerobic Condition
Biotechnology and Bioengineering, 2015Co-Authors: Ying Wang, Zhenyu ShiAbstract:Since solar light energy is the source of all renewable biological energy, the direct usage of light energy by bacterial cell factory has been a very attractive concept, especially using light energy to promote Anaerobic fermentation growth and even recycle low-energy carbon source when energy is the limiting factor. Proteorhodopsin(PR), a light-driven proton pump proven to couple with ATP synthesis when expressed heterogeneously, is an interesting and simple option to enable light usage in engineered strains. However, although it was reported to influence fermentation in some cases, heterogeneous proteorhodopsin expression was never shown to support growth advantage or cause metabolic shift by photophosphorylation so far. Hereby, we presented the first experimental evidence that heterogeneously expressed proteorhodopsin can provide growth advantage and cause ATP-dependent metabolism shift of acetate and lactate changes in Escherichia coli at Anaerobic Condition. Those discoveries suggest further application potential of PR in Anaerobic fermentation where energy is a limiting factor.
Jie Zhang - One of the best experts on this subject based on the ideXlab platform.
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insight into enrichment of Anaerobic ammonium oxidation bacteria in anammox granulation under decreasing temperature and no strict Anaerobic Condition comparison between continuous and sequencing batch feeding strategies
Science of The Total Environment, 2021Co-Authors: Wenqiang Wang, Ziqing Wei, Huiping Zeng, Jie ZhangAbstract:Abstract A continuous flow reactor (CFR) and a sequencing batch reactor (SBR) were operated in parallel to investigate the difference between anammox granulation in CFR and SBR under decreasing temperature and no strict Anaerobic Condition. The results showed that the biomass achieved initial granulation successfully (D [4, 3] = 280.44 and 346.28 μm) in both CFR and SBR on day 70. Compared with SBR, a better performance (0.33 kg N m−3 d−1) was gotten in CFR due to a better retention capacity of biomass (1397 mg L−1), when seasonal drop of water temperature occurred (18–14 °C). Thus, different operations led to different granulation styles of anammox. Granules in CFR had better rheological properties than that in SBR. Based on a stable and suitable environment provided by CFR, Anaerobic ammonium oxidation bacteria (AnAOB) are able to self-aggregate easily and secret extracellular polymeric substances (EPS), which can capture other bacteria as home guardians. In SBR, AnAOB live inside the tan granules under the protection of other bacteria and thick EPS; other aggregations stick to solid carrier surface to form biofilm.
Hitomi Ohara - One of the best experts on this subject based on the ideXlab platform.
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continuous production of d lactic acid from cellobiose in cell recycle fermentation using β glucosidase displaying escherichia coli
Journal of Bioscience and Bioengineering, 2019Co-Authors: Yuji Aso, Mikikazu Tsubaki, Bui Hoang Dang Long, Ryo Murakami, Keisuke Nagata, Hirohisa Okano, Ngo Thi Phuong Dung, Hitomi OharaAbstract:The present study demonstrates continuous production of d -lactic acid from cellobiose in a cell recycle fermentation with a hollow fiber membrane using recombinant Escherichia coli constructed by deleting its pyruvate formate-lyase activating enzyme gene pflA and expressing a heterologous β-glucosidase on its cell surface. The β-glucosidase gene bglC from Thermobifida fusca YX was cloned into a cell surface display vector pGV3, resulting in pGV3-bglC. Recombinant E. coli JM109 harboring the pGV3-bglC showed β-glucosidase activity (18.9 ± 5.7 U/OD600), indicating the cell surface functioning of mutant β-glucosidase. pH-stat cultivation using d -lactic acid producer E. coli BW25113 (ΔpflA) harboring pGV3-bglC in minimum medium with 10 g/L cellobiose in a jar fermentor under Anaerobic Condition resulted in 5.2 ± 0.1 g/L of d -lactic acid was obtained after 84 h cultivation, indicating that the engineered E. coli produced d -lactic acid directly from cellobiose. For continuous d -lactic acid production, cell recycle fermentation was conducted under Anaerobic Condition and the culture was continuously ultrafiltrated with a hollow fiber cartridge. The permeate was drawn to the reservoir and a minimum medium containing 10 g/L cellobiose was fed to the fermentor at the same rate (dilution rate, 0.05 h−1). Thus, this system maintained the d -lactic acid production (4.3–5.0 g/L), d -lactic acid production rate (0.22–0.25 g/L/h), and showed no residual cellobiose in the culture during 72 h operation. Interestingly, the d -lactic acid production rate in cell recycle fermentation was more than 3 times higher than that in the batch operation (0.06 ± 0.00 g/L/h).