Bacterially assembled biopolyester nanobeads for removing cadmium from water

Cadmium (Cd)-contaminated waterbodies are a worldwide concern for the environment, impacting human health. To address the need for efficient, sustainable and cost-effective remediation measures, we developed innovative Cd bioremediation agents by engineering Escherichia coli to assemble poly(3-hydroxybutyric acid) (PHB) beads densely coated with Cd-binding peptides. This was accomplished by translational fusion of Cd-binding peptides to the N- or C-terminus of a PHB synthase that catalyzes PHB synthesis and mediates assembly of Cd2 or Cd1 coated PHB beads, respectively. Cd1 beads showed greater Cd adsorption with 441 nmol Cd mg-1 bead mass when compared to Cd2 beads (334 nmol Cd mg-1 bead-mass) and plain beads (238 nmol Cd mg-1 bead-mass). The Cd beads were not ecotoxic and did attenuate Cd-spiked solutions toxicity. Overall, the bioengineered beads provide a means to remediate Cd-contaminated sites, can be cost-effectively produced at large scale, and offer a biodegradable and safe alternative to synthetic ecotoxic treatments.publishe

Simulation and optimisation of a two-stage/two-pass reverse osmosis system for improved removal of chlorophenol from wastewater

YesReverse osmosis (RO) has become a common method for treating wastewater and removing several harmful organic compounds because of its relative ease of use and reduced costs. Chlorophenol is a toxic compound for humans and can readily be found in the wastewater of a wide range of industries. Previous research in this area of work has already provided promising results in respect of the performance of an individual spiral wound RO process for removing chlorophenol from wastewater, but the associated removal rates have stayed stubbornly low. The literature has so far confirmed that the efficiency of eliminating chlorophenol from wastewater using a pilot-scale of an individual spiral wound RO process is around 83 %, compared to 97 % for dimethylphenol. This paper explores the potential of an alternative configuration of two-stage/two-pass RO process for improving such low chlorophenol rejection rates via simulation and optimisation. The operational optimisation carried out is enhanced by constraining the total recovery rate to a realistic value by varying the system operating parameters according to the allowable limits of the process. The results indicate that the proposed configuration has the potential to increase the rejection of chlorophenol by 12.4 % while achieving 40 % total water recovery at an energy consumption of 1.949 kWh/m³

Studies of a Ring-Cleaving Dioxygenase Illuminate the Role of Cholesterol Metabolism in the Pathogenesis of Mycobacterium tuberculosis

Mycobacterium tuberculosis, the etiological agent of TB, possesses a cholesterol catabolic pathway implicated in pathogenesis. This pathway includes an iron-dependent extradiol dioxygenase, HsaC, that cleaves catechols. Immuno-compromised mice infected with a ΔhsaC mutant of M. tuberculosis H37Rv survived 50% longer than mice infected with the wild-type strain. In guinea pigs, the mutant disseminated more slowly to the spleen, persisted less successfully in the lung, and caused little pathology. These data establish that, while cholesterol metabolism by M. tuberculosis appears to be most important during the chronic stage of infection, it begins much earlier and may contribute to the pathogen's dissemination within the host. Purified HsaC efficiently cleaved the catecholic cholesterol metabolite, DHSA (3,4-dihydroxy-9,10-seconandrost-1,3,5(10)-triene-9,17-dione; kcat/Km = 14.4±0.5 µM−1 s−1), and was inactivated by a halogenated substrate analogue (partition coefficient<50). Remarkably, cholesterol caused loss of viability in the ΔhsaC mutant, consistent with catechol toxicity. Structures of HsaC:DHSA binary complexes at 2.1 Å revealed two catechol-binding modes: bidentate binding to the active site iron, as has been reported in similar enzymes, and, unexpectedly, monodentate binding. The position of the bicyclo-alkanone moiety of DHSA was very similar in the two binding modes, suggesting that this interaction is a determinant in the initial substrate-binding event. These data provide insights into the binding of catechols by extradiol dioxygenases and facilitate inhibitor design

Emerging Technologies and Approaches to Minimize Discharges Into Lake Michigan Phase 2, Module 3 Report.

Purdue University Calumet (Purdue) and Argonne National Laboratory (Argonne) have conducted an independent study to identify deployable technologies that could help the BP Whiting Refinery, and other petroleum refineries, meet future wastewater discharge limits. This study has been funded by BP. Each organization tested a subset of the target technologies and retains sole responsibility for its respective test design and implementation, quality assurance and control, test results obtained from each of the technologies, and corresponding conclusions and recommendations. This project was divided in two phases and modules. This report summarizes the work conducted by Argonne in Phase II Module 3 (Bench Scale Testing). Other Modules are discussed elsewhere (Emerging Technologies and Approaches to Minimize Discharges into Lake Michigan, Phase 2, Modules 1-3 Report, April 2011, prepared for BP Americas by the Argonne - Purdue Task Force). The goal of this project was to identify and assess available and emerging wastewater treatment technologies for removing mercury and vanadium from the Whiting Refinery wastewater and to conduct bench-scale tests to provide comparable, transparent, and uniform results across the broad range of technologies tested. After the bench-scale testing phase, a previously developed decision matrix was refined and applied by Argonne to process and review test data to estimate and compare the preliminary performance, engineering configuration, preliminary cost, energy usage, and waste generation of technologies that were shown to be able to remove Hg and/or V to below the target limit at the bench scale. The data were used as the basis to identify the best candidates for further testing at the bench or pilot scale on a slip stream of effluent to lake (ETL) or clarifier effluent (CE) at the Whiting Refinery to determine whether future limits could be met and to generate other pertinent data for scale-up and sustainability evaluation. As a result of this technology assessment, Argonne identified several technologies that, at the bench-scale, could achieve the targeted performance for the removal of mercury and vanadium. A subset of those technologies were recommended for further testing either at the bench scale or at the pilot scale to determine whether future discharge limits could be met at the pilot-scale. The objectives of this project module are to: (1) Test at the bench-scale a subset of the technologies previously identified in Module 1 for the removal of target heavy metals down to 1.3 ppt Hg and 280 ppb V; (2) Review and process bench-scale test results on the basis of the end-point performance measures matrix to determine preliminary comparative performance, cost-effectiveness, and potential engineering configuration of tested technologies; (3) Assess the technological feasibility and readiness of the identified technologies for implementation at the Whiting Refinery; and (4) Select technically and economically feasible mercury- and vanadium-removal technologies and vendors to be recommended for pilot-scale testing at the Whiting Refinery

Morning blood pressure surge increases in patients with hypertensive primary hyperparathyroidism and is independently associated with serum calcium level

Introduction: There is not enough data on the effects of primary hyperparathyroidism (pHPT) on morning blood pressure surge (MBPS) in the literature. We aimed to determine whether there was any change in MBPS value in patients with hypertensive pHPT and to determine the parameters related to MBPS. Method: 80 patients with newly diagnosed pHPT with hypertension (HT) and 80 controls with newly diagnosed hypertension were included. Routine laboratory examinations and ambulatory blood pressure monitoring (ABPM) were performed in all patients. Results: In patients with pHPT, blood urea nitrogen (BUN), triglyceride, hs-CRP, uric acid, serum calcium (Ca), parathormone (PTH), daytime SBP and MBPS levels are higher than others (p < 0.05). Body mass index (BMI) and Ca level were independently associated with MBPS. In patients with MBPS ≥ 25 mmHg, BMI, BUN, creatinine, uric acid, Ca and PTH levels were found to be higher than others. BMI values and Ca levels determine the patients with MBPS ≥ 25 mmHg (p < 0.05) independently. According to this analysis, increase in BMI (for each 1 unit) and Ca level (for each 0.1 mg/dL) was found to increase the probability of MBPS ≥ 25 mmHg by 17.8% and 7.7%, respectively. When the cut-off value for Ca was taken as 10 mg/dL, the patients with MBPS ≥ 25 mmHg were determined with 73.5% sensitivity and 73.1% specificity. Conclusion: MBPS significantly increases in patients with newly diagnosed hypertensive pHPT. This increase in MBPS is closely associated with increased Ca levels. In patients with pHPT, lowering the Ca level below 10 mg/dL may have clinical implications

Electricity from lignocellulosic substrates by thermophilic Geobacillus species

Abstract Given our vast lignocellulosic biomass reserves and the difficulty in bioprocessing them without expensive pretreatment and fuel separation steps, the conversion of lignocellulosic biomass directly into electricity would be beneficial. Here we report the previously unexplored capabilities of thermophilic Geobacillus sp. strain WSUCF1 to generate electricity directly from such complex substrates in microbial fuel cells. This process obviates the need for exogenous enzymes and redox mediator supplements. Cyclic voltammetry and chromatography studies revealed the electrochemical signatures of riboflavin molecules that reflect mediated electron transfer capabilities of strain WSUCF1. Proteomics and genomics analysis corroborated that WSUCF1 biofilms uses type-II NADH dehydrogenase and demethylmenaquinone methyltransferase to transfer the electrons to conducting anode via the redox active pheromone lipoproteins localized at the cell membrane

Emerging Technologies and Approaches to Minimize Discharges Into Lake Michigan, Phase 2 Module 4 Report.

The Great Lakes Initiative (GLI) established the new water quality-based discharge criteria for mercury (Hg), thereby increasing the need for many municipal and industrial wastewater treatment plants in the region to lower the mercury in their effluents. Information on deployable technologies to satisfy these requirements for industrial and municipal dischargers in the Great lakes region is scarce. Therefore, BP funded Purdue University Calumet and Argonne to identify deployable Hg removal technologies to meet the GLI discharge criterion at its Whiting Refinery in Indiana. The joint PUC/Argonne project was divided into 2 phases. Results from Phase I and Phase II Modules 1-3 have been previously reported. This report summarizes the work done in Phase 3 Module 4, which consisted of the pilot scale testing of Hg removal technologies previously selected in Module 3. The pilot testing was an Argonne/PUC jointly directed project that was hosted at and funded by the BP refinery in Whiting, IN. As two organizations were involved in data analysis and interpretation, this report combines two independent sets of evaluations of the testing that was done, prepared respectively by Argonne and Purdue. Each organization retains sole responsibility for its respective analysis conclusions and recommendations. Based on Module 3 bench testing with pre-Effluent To Lake (pre-ETL) and clarifier effluent (CE) samples from the Whiting refinery, three different technologies were chosen for pilot testing: (1) Ultrafiltration (using GE ZeeWeed(reg sign) Technology, 0.04 {mu}m pore size and made up of PVDF) for particulate mercury removal; (2) Adsorption using Mersorb(reg sign) LW, a sulfur-impregnated activated carbon, for dissolved mercury removal if present and (3) The Blue PRO(reg sign) reactive filtration process for both particulate and dissolved (if present) mercury removal. The ultrafiltration and the Blue PRO(reg sign) reactive filtration pilot studies were done simultaneously at the BP Whiting refinery using a slipstream of wastewater taken just prior to the Effluent to lake (pre-ETL) outfall. It was the intention of this pilot testing to demonstrate proof of concept, i.e. can the discharge limits obtained at bench scale be consistently met at the pilot scale. Although Mersorb(reg sign) LW was selected for dissolved mercury removal testing, this technology was not pilot tested because of a lack of dissolved mercury in the test wastewater during the pilot study. The overall objective of this pilot testing was to demonstrate the effectiveness of the tested technologies with continuous and varying feed conditions to meet the GLI criterion (1.3 ppt). Optimization for full-scale design was outside of the scope of this work. In addition to demonstrating whether the Hg criterion can be met, information on residue generation rate, frequency of backwashing and other maintenance issues were collected to better understand the implications for a full-scale system

Printing-Assisted Surface Modifications of Patterned Ultrafiltration Membranes

Understanding and restricting microbial surface attachment will enhance wastewater treatment with membranes. We report a maskless lithographic patterning technique for the generation of patterned polymer coatings on ultrafiltration membranes. Polyethylene glycol, zwitterionic, or negatively charged hydrophilic polymer compositions in parallel- or perpendicular-striped patterns with respect to feed flow were evaluated using wastewater. Membrane fouling was dependent on the orientation and chemical composition of the coatings. Modifications reduced alpha diversity in the attached microbial community (Shannon indices decreased from 2.63 to 1.89) which nevertheless increased with filtration time. <i>Sphingomonas</i> species, which condition membrane surfaces and facilitate cellular adhesion, were depleted in all modified membranes. Microbial community structure was significantly different between control, different patterns, and different chemistries. This study broadens the tools for surface modification of membranes with polymer coatings and for understanding and optimization of antifouling surfaces