Vertical distribution and migration of heavy metals in soil of green stormwater infrastructure receiving roof runoff.

In order to achieve effective management of urban stormwater runoff, green stormwater infrastructure (GSI) has been widely used worldwide. However, the problem of heavy metal contamination in GSI soils has gradually become a limiting factor for their development. In this paper, concentrations of 6 heavy metals were detected in soils from 0 to 80 cm depth in the GSI receiving roof runoff.

A wafer scale thin film of ultra-small ScO nanocrystals on a 2D COF with high rigidity.

Scandium oxide (ScO) has a wide range of applications in metallurgy, chemical industry, electronics and many other high-tech fields. However, most ScO materials exist in the powder or bulk form, while nanostructured ScO has rarely been reported as there is a lack of a common method to control its dimensionality, hindering the understanding of new properties and potential applications of nano-ScO materials. In this paper, we establish a procedure to synthesize a two-dimensional (2D) ScO-covalent organic framework (COF) composite film where the crystal size of ScO domains is as small as ∼3 nm.

Exploring the molecular mechanism of Chlorella vulgaris in response to androstenedione exposure based on genes continuously up-regulated in transcription analysis.

Androstenedione (ADSD) is one of the widely detected androgens in diverse aquatic environments. However, there were few reports on the molecular mechanism of Chlorella vulgaris exposure to ADSD. In our previous research, we have investigated the genes associated with chlorophyll metabolism in Chlorella vulgaris response to ADSD.

Machine Learning in Bioelectrocatalysis.

At present, the global energy crisis and environmental pollution coexist, and the demand for sustainable clean energy has been highly concerned. Bioelectrocatalysis that combines the benefits of biocatalysis and electrocatalysis produces high-value chemicals, clean biofuel, and biodegradable new materials. It has been applied in biosensors, biofuel cells, and bioelectrosynthesis.

The material-microorganism interface in microbial hybrid electrocatalysis systems.

This review presents a comprehensive summary of the material-microorganism interface in microbial hybrid electrocatalysis systems. Microbial hybrid electrocatalysis has been developed to combine the advantages of inorganic electrocatalysis and microbial catalysis. However, electron transfer at the interfaces between microorganisms and materials is a very critical issue that affects the efficiency of the system.

Cation affinity purification of histidine-tagged proteins.

Protein purification is a basic technology in both biological research and industrial production, and efficient, convenient, economical, and environmentally friendly purification methods have always been pursued. In this study, it was found that alkaline earth metal cations (Mg, Ca) and alkali metal cations (Li, Na, K) and even nonmetal cations (e.g.

Encapsulation of Nitrilase in Zeolitic Imidazolate Framework-90 to Improve Its Stability and Reusability.

In this study, nitrilase (Nit) was immobilized in zeolite imidazole framework-90 (ZIF-90) by one-pot biomimetic mineralization strategy. The structure, morphology and functional groups of ZIF-90 and immobilized enzyme Nit@ZIF-90 were characterized by scanning electron microscopy (SEM)/energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FT-IR). Circular dichroism (CD) proved that the immobilized method of encapsulation in ZIF-90 could effectively maintain the intrinsic conformation of Nit.

Effect of SpyTag/SpyCatcher cyclization on stability and refolding of green fluorescent protein.

To study the effect of SpyTag/SpyCatcher cyclization on stability and refolding of protein, we constructed a cyclized green fluorescent protein (SRGFP) and its derivative to act as a linear structure control (L-SRGFP). SRGFP and L-SRGFP showed similar fluorescence characteristics to the wild-type GFP, while compared with GFP and L-SRGFP, the thermal stability and denaturation resistance of SRGFP were improved. The refolding efficiencies of these three denatured proteins were investigated under different pH, temperature and initial protein concentration conditions, and it was found that SRGFP was superior to GFP and L-SRGFP in terms of refolding yield and refolding speed.

Coupled synthetic pathways improve the production of 3-hydroxypropionic acid in recombinant strains.

To improve the production of 3-HP with glucose as a substrate, the malonyl-CoA and propionyl-CoA pathways were coupled to regulate NADP/NADPH regeneration in the recombinant . The strain -AM that overexpressed the key enzymes of the malonyl-CoA pathway, acetyl CoA carboxylase (ACC) from and malonyl CoA reductase (MCR) from , produced 0.26 g/L of 3-HP in 25-h shake flask cultivation.

SpyTag/Catcher chemistry induces the formation of active inclusion bodies in E. coli.

SpyTag/Catcher chemistry is usually applied to engineer robust enzymes via head-to-tail cyclization using spontaneous intramolecular isopeptide bond formation. However, the SpyTag/Catcher induced intercellular protein assembly in vivo cannot be ignored. It was found that some active inclusion bodies had generated to different proportions in the expression of six SpyTag/Catcher labeled proteins (CatIBs-STCProtein).

One-step purification and immobilization of recombinant proteins using SpyTag/SpyCatcher chemistry.

Based on the specific and spontaneous formation of isopeptide bonds by SpyCatcher/SpyTag, we have developed a one-step method for purification and immobilization of recombinant proteins. The procedure is to immobilize SpyCatcher on glyoxyl agarose gels, and then the SpyCatcher immobilisate can be used to immobilize the SpyTag-fused protein in the crude extract selectively. A mutant of SpyCatcher (mSC), in which a peptide (LysGlyLysGlyLysGly) was added to the C-terminus of SpyCatcher and three lysine residues around the SpyTag/SpyCatcher binding domain were replaced with arginine, was designed to improve the attachment of SpyCatcher to the support.

Optimization of Cephalosporin C Acylase Expression in Escherichia coli by High-Throughput Screening a Constitutive Promoter Mutant library.

Cephalosporin C acylase (CCA) is capable of catalyzing cephalosporin C (CPC) to produce 7-aminocephalosporanic acid (7-ACA), an intermediate of semi-synthetic cephalosporins. Inducible expression is usually used for CCA. To improve the efficiency of CCA expression without gene induction, three recombinant strains regulated by constitutive promoters BBa_J23105, PLtetO1, and tac were constructed, respectively.

Effect of shaking speed on immobilization of cephalosporin C acylase: Correlation between protein distribution and properties of the immobilized enzymes.

During enzyme immobilization, enzyme activity and protein distribution are affected by various factors such as enzyme load, temperature, and pH. In general, two types of protein distribution patterns (heterogeneous or homogeneous) are observed inside a porous carrier, owing to differences in preparation parameters. During the immobilization of a fusion protein (CCApH) of cephalosporin C acylase (CCA) and pHluorin (a pH-sensitive mutant of green fluorescent protein), different shaking speeds induced obvious differences in protein distribution on an epoxy carrier, LX-1000EPC.

Differentially proteomic analysis of the hemocytes against Aeromonas hydrophila infection in oriental river prawn Macrobrachium nipponense by iTRAQ approach.

As the direct executors of biological function, the expression level of proteins in host will reveal the molecular mechanisms regulating bacteria infection more directly. In the present study, the differential proteomes of Macrobrachium nipponense hemocytes response to Aeromonas hydrophila infection were identified with isobaric tags for relative and absolute quantitation (iTRAQ) labeling followed by liquid chromatography electrospray ionization tandem mass spectrometry. The hemocyte proteins from the unchallenged and A.

High-Throughput Screening of T7 Promoter Mutants for Soluble Expression of Cephalosporin C Acylase in E. coli.

Cephalosporin C acylase (CCA) is the key enzyme in the production of 7-aminocephalosporanic acid (7-ACA) via a one-step enzymatic process. To improve the soluble expression level of CCA in recombinant Escherichia coli at elevated temperatures, a library of T7 promoter mutants was created by site-saturation mutagenesis, and a series of mutated promoters were subsequently screened. Green fluorescent protein (GFP) was fused to the C-terminus of CCA to facilitate library screening, and the expression of the CCA and GFP fusion proteins was investigated under the control of the T7 promoter.

SpyTag/SpyCatcher cyclization enhances the thermostability and organic solvent tolerance of L-phenylalanine aldolase.

Objectives: To improve the thermostability and organic solvent tolerance of L-phenylserine aldolase, the in vivo SpyTag/SpyCatcher cyclization strategy was applied in this work.

Results: The in vivo cyclization of L-phenylserine aldolase was achieved by fusing the tags of SpyCatcher and SpyTag to the N- and C-termini of the enzyme, respectively. The k values and the circular dichroism spectra of the linear and cyclized LPAs are very similar, indicating that the cyclized LPA can be folded appropriately like the wild type.

Application of ammonium bicarbonate buffer as a smart microenvironmental pH regulator of immobilized cephalosporin C acylase catalysis in different reactors.

In a stirred tank reactor, during catalysis with immobilized cephalosporin C acylase (CCA), the microenvironmental pH dropped to 7.2 in a nonbuffered system (with the pH maintained at 8.5 by adding alkali) due to the existence of diffusional resistance.

Quantification Challenges for Atom Probe Tomography of Hydrogen and Deuterium in Zircaloy-4.

Analysis and understanding of the role of hydrogen in metals is a significant challenge for the future of materials science, and this is a clear objective of recent work in the atom probe tomography (APT) community. Isotopic marking by deuteration has often been proposed as the preferred route to enable quantification of hydrogen by APT. Zircaloy-4 was charged electrochemically with hydrogen and deuterium under the same conditions to form large hydrides and deuterides.

Ti and its alloys as examples of cryogenic focused ion beam milling of environmentally-sensitive materials.

Hydrogen pick-up leading to hydride formation is often observed in commercially pure Ti (CP-Ti) and Ti-based alloys prepared for microscopic observation by conventional methods, such as electro-polishing and room temperature focused ion beam (FIB) milling. Here, we demonstrate that cryogenic FIB milling can effectively prevent undesired hydrogen pick-up. Specimens of CP-Ti and a Ti dual-phase alloy (Ti-6Al-2Sn-4Zr-6Mo, Ti6246, in wt.

The Laplace Project: An integrated suite for preparing and transferring atom probe samples under cryogenic and UHV conditions.

We present sample transfer instrumentation and integrated protocols for the preparation and atom probe characterization of environmentally-sensitive materials. Ultra-high vacuum cryogenic suitcases allow specimen transfer between preparation, processing and several imaging platforms without exposure to atmospheric contamination. For expedient transfers, we installed a fast-docking station equipped with a cryogenic pump upon three systems; two atom probes, a scanning electron microscope / Xe-plasma focused ion beam and a N2-atmosphere glovebox.

Comparative proteomic analysis between two haemocyte subpopulations in shrimp Fenneropenaeus chinensis.

In our previous work, granulocytes and hyalinocytes were successfully separated by immunomagnetic bead (IMB) method using monoclonal antibodies (mAbs) against granulocytes of shrimp (Fenneropenaeus chinensis). In order to elucidate the proteomic differentiation between granulocytes and hyalinocytes, in this paper, the differentially expressed proteins were analyzed between non-fixed/un-permeabilized (NFP) haemocytes and fixed/permeabilized (FP) haemocytes using two-dimensional gel electrophoresis (2-DE) combined with mass spectrometry (MS). Then the FP haemocytes were separated into two haemocyte subpopulations using IMB method, and the comparative proteome between granulocytes and hyalinocytes was investigated.

Separation of haemocyte subpopulations in shrimp Fenneropenaeus chinensis by immunomagnetic bead using monoclonal antibody against granulocytes.

In our previous work, two monoclonal antibodies (Mabs) against granulocytes of shrimp (Fenneropenaeus chinensis) had been produced, in this paper, haemocyte subpopulations were analyzed by flow cytometry (FCM) using the Mabs. Then immunomagnetic bead (IMB) method was applied for separation hyalinocytes and granulocytes using the Mabs. The separated hyalinocytes and granulocytes were analyzed by FCM, indirect immunofluorescence assay, Giemsa staining and transmission electron microscopy, respectively.

Microenvironmental pH changes in immobilized cephalosporin C acylase during a proton-producing reaction and regulation by a two-stage catalytic process.

Cephalosporin C acylase (CCA), a proton-producing enzyme, was covalently bound on an epoxy-activated porous support. The microenvironmental pH change in immobilized CCA during the reaction was detected using pH-sensitive fluorescein labeling. The high catalytic velocity of the initial stage of conversion resulted in a sharp intraparticle pH gradient, which was likely the key factor relating to low operational stability.

Production of 3-Hydroxypropionic Acid via the Propionyl-CoA Pathway Using Recombinant Escherichia coli Strains.

Our study aimed to produce the commercially promising platform chemical 3-hydroxypropionic acid (3-HP) via the propionyl-CoA pathway in genetically engineered Escherichia coli. Recombinant E. coli Ec-P overexpressing propionyl-CoA dehydrogenase (PACD, encoded by the pacd gene from Candida rugosa) under the T7 promoter produced 1.

Directed Evolution and Mutant Characterization of Nitrilase from Rhodococcus rhodochrous tg1-A6.

In this paper, a molecularly directed evolution-based approach was applied to modify the nitrilase from Rhodococcus rhodochrous tg1-A6 for improving properties in catalyzing nitriles. In the process of error-prone polymerase chain reaction (PCR) with the wild-type nitrilase gene acting as the template, a library of the randomly mutated nitrilase gene was constructed. Since the pH value of catalyzing solution decreased when glycolonitrile was used as the substrate of nitrilase, a high-throughput strategy based on the color change of a pH-sensitive indicator was established for rapid screening of the mutated nitrilase.