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BACKGROUND: Quinoline is an ubiquitous pollutant widely spread in the environment, which can be eliminated efficiently by microbial degradation In this study, two quinoline-degrading Comamonas sp strains Z1 and Z3 were isolated from activated sludge, and the degradation characteristics and genome annotation were investigated in detail RESULTS: Strain Z1 exhibited a superior capacity for quinoline degradation, which could completely degrade 50–300 mg L−1 quinoline within 8–24 h, whereas strain Z3 required 14–36 h to remove 50–200 mg L−1 quinoline The suitable pHs for strains Z1 and Z3 were 8 0 and 7 0, respectively, and metal ions such as Mn2+, Ni2+, Cu2+, Co2+ and Hg2+ could greatly inhibit bacterial growth and quinoline degradation Intermediates of 2-hydroxyquinoline, 2,8-dihydroxyquinoline, 8-hydroxycoumarin, 2,3-dihydroxyphenylpropionic acids and 2-hydroxy-6-oxonona-2,4-diene-1,9-dioate were detected by liquid chromatography coupled to Q-Exactive high-resolution mass spectrometry Thus, the biodegradation of quinoline by Comamonas sp strains possibly proceeded via the 8-hydroxycoumarin pathway Genomic sequencing of strains Z1 and Z3 revealed a similar pattern, and a large number of functional genes were predicted to participate in degradation of aromatics The key genes responsible for quinoline degradation also were identified, such as qor, mhp and bph Furthermore, quinoline 2-oxidoreductase (Qor) from strains Z1 and Z3 displayed 47 74%–61 17% similarities with previously reported Qor, which catalyzed the first step of quinoline degradation, and the maximal specific activity in cell-free extracts of strains Z1 and Z3 was 0 264 and 0 062 U mg protein−1, respectively CONCLUSION: This study should provide efficient microbial resources and useful genomic information for quinoline bioremediation © 2020 Society of Chemical Industry

Chromium (VI) [Cr(VI)] is considered to be a serious environmental pollutant because of its highly carcinogenic and mutagenic properties. In this study, we fabricated fluorescent probes for Cr(VI) ...

The toxicity of polystyrene (PS) particles of different sizes was investigated using Gram-negative Escherichia coli and Gram-positive Bacillus cereus. PS particles could inhibit the cell growth of E. coli but promote the cell growth of B. cereus, and this difference might be attributed to different composition in their cell walls and the different interactions between the two bacteria and PS particles. Direct adhesion of E. coli cells on the surface of 5 μm PS microbeads by flagella was observed, indicating the putative role of E. coli on biofilm formation of plastisphere. The regulations of malondialdehyde, lactate dehydrogenase and glutathione were similar between the two bacteria, so the difference in the toxicity effect of PS between the two bacteria was not caused by the antioxidant activity. The overall results of the present study could help to understand the responses of different bacteria to microplastic exposure.

An organic-silica hybrid monolithic capillary column was fabricated by crosslinking (3-aminopropyl)trimethoxysilane (APTMS) modified mesoporous carbon nanoparticles (AP-MCNs) with tetramethoxysilane (TMOS) and n-butyltrimethoxysilane (C4-TriMOS). Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy, mercury intrusion porosimetry and inverse size-exclusion chromatography characterization proved the successful immobilization of mesoporous carbon nanoparticles (MCNs). The crosslinking of AP-MCNs into the hybrid monolithic matrix has significantly increased the reversed-phase retention of alkylbenzenes and chromatographic performance for small molecules separations in comparison with the neat one without MCNs. The resulting column efficiency of the mesoporous carbon nanoparticle-based butyl-silica hybrid monolithic column (MCN-C4-monolith) was up to ca. 116,600 N/m for the capillary liquid chromatography (cLC) separation of butylbenzene. Enhanced performance of proteins separation was achieved on the MCN-C4-monolith in comparison with the butyl-silica hybrid monolithic column without MCN (C4-monolith). The separation of peptides from bovine serum albumin (BSA) digest was carried out on the MCN-C4-monolith by capillary liquid chromatography–tandem mass spectrometry (cLC–MS/MS) with protein sequence coverage of 81.9%, suggesting its potential application in proteomics.

Prorocentrum lima is a dinoflagellate that forms hazardous blooms and produces okadaic acid (OA), leading to adverse environmental consequences associated with the declines of zooplankton populations. However, little is known about the toxic effects and molecular mechanisms of P. lima or OA on zooplankton. Here, their toxic effects were investigated using the brine shrimp Artemia salina. Acute exposure of A. salina to P. lima resulted in lethality at concentrations 100-fold lower than densities observed during blooms. The first comprehensive results from global transcriptomic and metabolomic analyses in A. salina showed up-regulated mRNA expression of antioxidant enzymes and reduced non-enzyme antioxidants, indicating general detoxification responses to oxidative stress after exposure to P. lima. The significantly up-regulated mRNA expression of proteasome, spliceosome, and ribosome, as well as the increased fatty acid oxidation and oxidative phosphorylation suggested the proteolysis of damaged proteins and induction of energy expenditure. Exposure to OA increased catabolism of chitin, which may further disrupt the molting and reproduction activities of A. salina. Our data shed new insights on the molecular responses and toxicity mechanisms of A. salina to P. lima or OA. The simple zooplankton model integrated with omic methods provides a sensitive assessment approach for studying hazardous algae.

Polyethylenimine (PEI) and 2,4,6,8-tetramethyl-2,4,6,8-tetrakis(propyl glycidyl ether)cyclotetrasiloxane (POSS–epoxy) were used as precursors for the preparation of organic-silica hybrid monolithic columns (PEI–POSS monolith) via epoxy–amine ring-opening polymerization (ROP). The high density of amine groups in PEI provides rich chromatographic interaction sites for the polar or acidic analytes in hydrophilic interaction (HILIC) and weak anion exchange (WAX) mechanisms. The column preparation conditions, such as the porogens, solvent and reaction temperature, were systematically investigated according to the morphology, permeability and column efficiency. The separation mechanisms of HILIC and WAX were evaluated with neutral polar compounds and halogen benzoic acids. Owing to the existence of reactive amine groups on the matrix surface, the PEI–POSS monolith is also an ideal starting material for the preparation of HILIC or strong anionic exchange (SAX) stationary phases by modification. The modification of PEI–POSS monoliths with iodomethane or bromoacetic acid via the nucleophilic substitution reaction could achieve the retention mechanisms of SAX or zwitterionic HILIC, respectively.

Tiny changes in the mass of the sensor in a quartz crystal microbalance with dissipation monitoring (QCM-D) can be observed. However, the lack of specificity for target species has hindered the use of QCM-D. Here, molecularly imprinted polymers (MIPs) were used to modify a QCM-D sensor to provide specificity. The MIPs were formed in the presence of sodium dodecyl benzene sulfonate. Imprinted layers on Fe3O4 nanoparticles were formed using pyrrole as the functional monomer and cross-linker and methylene blue (MB) as a template. The MIPs produced were then attached to the surface of a QCM-D sensor. The MIPs-coated QCM-D sensor could recognize MB and gave a linear response in the concentration range 25 to 1.5 &times, 102 &micro, g/L and a detection limit of 1.4 &micro, g/L. The QCM-D sensor was selective for MB over structural analogs. The MIPs-coated QCM-D sensor was successfully used to detect MB in river water and seawater samples, and the recoveries were good. This is the first time MB has been detected using a QCM-D sensor. Mass is an intrinsic property of matter, so this method could easily be extended to other target species by using different MIPs.

A simple magnetization method was developed for the preparation of magnetic materials from conventional solid phase packing though coprecipitation and solvothermal approaches. And the prepared magnetic materials were used for magnetic solid phase extraction (MSPE) of biogenic amines (BAs) from beers. Furthermore, to improve the analytical throughput, a solid phase “on-situ” quadraplex isotope dimethyl labeling method was developed for the quantification of BAs by liquid chromatography-high resolution mass spectrometry (LC HRMS). Compared to conventional in-solution labeling, the “on-situ” labeling could simplify the sample preparation procedure and efficiently remove the residuals such as inorganic salts and excessive labeling reagents. The quadraplex labeling, which enabled three real samples and one internal standard sample to be analyzed simultaneously in a single LC HRMS run. For the tested 8 BAs (cadaverine, phenethylamine, spermine, spermidine, tyramine, histamine, putrescine and tryptamine), LODs of 0.02–0.05 μg/L and LOQs of 0.05–0.1 μg/L were achieved at good reproducibility (RSD of 0.5–4.6% and 2.2–7.0% for intra- and inter-day reproducibility, respectively). With this method, six beer samples were analyzed, and these 8 BAs were all detected in the range of low μg/L to 2.9 mg/L, which were lower than maximal residual level (MRL) required in the regulations of China and EU.

Aims Methane and methanol are potential carbon sources of industrial microorganisms in addition to crop-derived bio-carbon sources. Methanotrophs that can utilize these simple, stable and large amounts chemicals are expected to be developed into “cell factories” for the production of specific chemicals. In this study,a methanotroph that can synthesize lycopene, C30 carotenoid and exopolysaccharides with relative better performances from C1 substrates was isolated, and its performances were evaluated. Methods and results The isolated strain was identified as Methylomonas sp. ZR1 based on 16S rRNA sequence analysis. Its maximum specific growth rate achieved 0.200 h−1 under flask culture conditions, and 0.386 h−1 in bubble column reactors. ZR1 was able to utilize 35 g l−1 of methanol and even exhibited slight growth in the presence of 40 g l−1 of methanol. Furthermore, ZR1 was proved to synthesize lycopene (C40 carotenoids) besides the C30 carotenoids through HPLC-DAD and HPLC-MS/MS analysis methods. Its carotenoid extracts exhibited excellent anti-oxidative activities measured by the ABTS·+ method. Plenty of polysaccharides were also synthesized by ZR1, the components of the polysaccharides were identified as glucose, mannose, and galactose with a proportion of 1:2:1by GC-MS, and its yield achieved 0.13 g/g cell dry weight (CDW). Conclusions The isolated strain has great potential for the production of value-added bioproducts from C1 compounds because of its excellent C1 substrate utilizing abilities and its abilities to naturally synthesize lycopene, C30 carotenoids and exopolysaccharides. This article is protected by copyright. All rights reserved.

Hydrophobic organicinorganic hybrid monolithic columns were synthesized via thermally initiated free radical polymerization with the confines of 75 mu m id capillary using a polyhedral oligomeric silsesquioxane (poss) reagent containing eight or more methacrylate groups as the crosslinker. three organic functional monomers, butyl methacrylate (buma), lauryl methacrylate (lma) and methacrylic acid (maa), were selected and copolymerized with the poss in the presence of 1-propanol and 1,4-butanediol to prepare the poly(poss-co-buma), poly(poss-co-lma), and poly(poss-co-maa) monoliths, respectively. the 2-acrylamido-2-methyl-1-propanesulfonic acid (amps) was copolymerized as ionizable monomer into the poly(poss-co-buma) and poly(poss-co-lma) for the generation of eof in capillary electrochromatography (cec). a hybrid poly(poss-co-lma-co-maa) monolith was also similarly prepared by copolymerizing ternary monomers of poss, lma, and maa, and compared with poly(poss-co-buma), poly(poss-co-lma), and poly(poss-co-maa) monoliths. the resulting four kinds of poss-contained hybrid monoliths exhibited good permeability and mechanical stability. their column efficiencies were evaluated by the separation of alkylbenzene homologues and polar compounds in cec. the results indicated that the highest efficiencies of 194?100 and 102?100 theoretical plates per meter for thiourea and benzene were obtained on the poly(poss-co-lma-co-maa) monolith. additionally, the poly(poss-co-lma-co-maa) monolith exhibited better selectivity for separation of polar compounds than those of other hybrid monoliths.

A chloropropyl-functionalized silica (CP-silica) hybrid monolithic column was synthesized within the confines of a capillary via the sol–gel process using tetramethoxysilane (TMOS) and (3-chloropropyl)-trimethoxysilane (CPTMS) as the precursors. The resulting CP-silica hybrid monolith inside the capillary showed homogeneous macroporous morphology and was well attached to the inner wall of the capillary. The obtained CP-silica hybrid monolithic capillary column demonstrated the inherent hydrophobic property and could be applied as a reversed-phase stationary phase in CEC directly. Due to the great chemical reactivity of the incorporated chloro groups on the hybrid silica monolithic matrix, the chloropropyl moieties on the surface of the hybrid silica monolith matrix could be conveniently further modified by a tertiary amine of N,N-dimethyl-N-dodecylamine (DMDA) via the nucleophilic substitution reaction at 70 °C to introduce a dodecyl groups (C12) onto the CP-silica hybrid monolithic matrix. The resulting C12-silica hybrid monolithic column not only demonstrated the significantly enhanced hydrophobic property in the separation of alkylbenzenes in reversed-phase capillary electrochromatography (RP-CEC), but also the strong electroosmotic flow (EOF) in a wide pH range. Five alkylbenzenes could be baseline separated in 3 min with column efficiency ranging from 189 700 to 221 000 N/m with a 70% ACN running buffer in CEC.

The stationary phases including the nonpolar and polar stationary phases in microscale separations have been greatly developed. This review describes the recent progress of the polar stationary phases (PSPs) with the focus on their preparation and the interesting applications in the field of CEC and capillary liquid chromatography (CLC) covering the literatures from the middle of 2006 to the middle of 2008. The PSPs described herein were summarized into three types as open-tubular, particle-packed and monolithic stationary phases for either CEC or CLC, and the separation mechanisms are of hydrophilic interaction, chiral selection, ion-exchange and/or electrostatic interaction, etc. After overviewing the literatures published in the last 2 years, the research efforts on PSPs for CEC and CLC have been remaining in the fabrication of open-tubular and monolithic capillary columns; whereas, the research endeavor of PSPs on particulate-packed format seemed to decline most likely due to the commercial availability of various packing particles for CEC and CLC.

A chiral capillary monolithic column for capillary electrochromatography (CEC) was prepared by covalent bonding of cellulose tris(3,5-dimethylphenylcarbamate) (CDMPC) on the silica monolithic matrix within the confine of a 50-μm i.d. bare fused silica capillary. Several pairs of enantiomers including neutral and basic analytes were baseline resolved on the newly prepared chiral capillary monolithic column in CEC with aqueous mobile phases. Fast enantioseparation was achieved due to the favorable dynamic properties of silica monolith. The covalent bonding of CDMPC as the chiral stationary phase for CEC also enabled the use of THF in mobile phase for enantioseparation of prazquantel by overcoming the incompatibility of THF and the physically coated CDMPC on a column.

An approach of immobilizing mobile crystalline material (MCM)-41 mesoporous silica nanoparticles on the inner wall of an open-tubular (OT) capillary as the support for coating chiral selector of cellulose tris(3,5-dimethylphenyl-carbamate) (CDMPC) was carried out. By taking advantage of the improved phase ratio of OT capillary with the immobilization of MCM-41 mesoporous material, the cellulose derivative of CDMPC as the chiral selector was simply coated on the MCM-41 nanoparticle layer via the hydrogen-bonding interaction, and the enantioseparation was successively carried out. Eight pairs of acidic, neutral and basic enantiomers were resolved in capillary electrochromatography or capillary liquid chromatography mode. The concentration of CDMPC for coating was systematically investigated to obtain the optimized chromatographic properties on enantioseparation by controlling the supposed film thickness of CDMPC on MCM-41 nanoparticle layer. Comparing with a bare fused silica capillary column coated with CDMPC under the same coating procedure as MCM-41-modified capillary did, the MCM-41-modified capillary column offered much higher enantioselectivity. This result indicated the significance of using the mesoporous nanoparticles as the electrochromatographic support to enhance the phase ratio of OT capillary column in capillary electrochromatography and capillary liquid chromatography. For investigating the effect of experimental conditions on the enantioseparation with this prepared OT capillary column, the content of organic modifier acetonitrile in the mobile phase was thus extensively evaluated to achieve a better chiral separation.

Acesulfame (ACE) and sucralose (SUC) have become recognized as ideal domestic wastewater contamination indicators. Liquid chromatography-electrospray ionization mass spectrometry (LC-ESI-MS) analysis is commonly used; however, the sensitivity of SUC is more than two orders of magnitude lower than that of ACE, limiting the routine monitoring of SUC. To address this issue, we examined the ESI behavior of both ACE and SUC under various conditions. ACE is ionic in aqueous solution and efficiently produces simple [M − H] − ions, but SUC produces multiple adduct ions, limiting its sensitivity. The formic acid (FA) adducts of SUC [M + HCOO] − are sensitively and reproducibly generated under the LC-MS conditions. When [M + HCOO] − is used as the precursor ion for SUC detection, the sensitivity increases approximately 20-fold compared to when [M − H] − is the precursor ion. To further improve the limit of detection (LOD), we integrated the large volume injection approach (500 μL injection) with ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS), which reduced the method detection limit (MDL) to 0.2 ng/L for ACE and 5 ng/L for SUC. To demonstrate the applicability of this method, we analyzed 100 well water samples collected in Alberta. ACE was detected in 24 wells at concentrations of 1–1534 ng/L and SUC in 8 wells at concentrations of 65–541 ng/L. These results suggest that wastewater is the most likely source of ACE and SUC impacts in these wells, suggesting the need for monitoring the quality of domestic well water.

A novel thiol-ene "click" strategy for the preparation of monolithic trypsin microreactor was proposed. The hybrid organic-inorganic monolithic capillary column with ene-functionality was fabricated by sol-gel process using tetramethoxysilane (TMOS) and γ-methacryloxypropyltrimethoxysilane (γ-MAPS) as precursors. The disulfide bonds of trypsin were reduced to form free thiol groups. Then the trypsin containing free thiol groups was attached on the γ-MAPS hybrid monolithic column with ene-functionality via thiol-ene click chemistry to form a trypsin microreactor. The activity of the trypsin microreactor was characterized by detecting the substrate (Nα-p-tosyl-L-arginine methyl ester hydrochloride, TAME) and the product (Nα-p-tosyl-L-arginine, TA) with on-line capillary zone electrophoresis. After investigating various synthesizing conditions, it was found that the microreactor with poly(N,N'-methylenebisacrylamide) as spacer can deliver the highest activity, yielding a rapid reaction rate. After repeatedly sampling and analyzing for 100 times, the monolithic trypsin microreactor still remained 87.5% of its initial activity. It was demonstrated that thiol-ene "click" strategy for the construction of enzyme microreactor is a promising method for the highly selective immobilization of proteins under mild conditions, especially enzymes with free thiol radicals.

Organic-silica hybrid monolithic columns have drawn more and more attention due to the ease of preparation and good mechanical stability in recent years. Many synthetic approaches have been developed and a variety of hybrid monolithic capillary columns have been prepared. The sol-gel process is well recognized in the fabrication of hybrid monolithic columns, which can be mainly classified as one-step, acid/base two-step procedures. The new approaches such as the " one-pot'' and nano-scaled inorganic-organic hybrid reagent of polyhedral oligomeric silsesquioxane used as a cross-linker have also emerged for the preparation of hybrid monolithic columns. The applications of the organic-silica hybrid monolithic capillary columns for capillary electrochromatography, micro high-performance liquid chromatography, solid-phase microextraction and enzymatic reactor etc. are included in this review.

As the development of monolithic stationary phases in CEC and capillary LC, the monoliths specifically related with the enantioseparations taking the advantages of monolithic stationary phases have attracted increased research interest in this field. This short review describes recent progress with emphasis on the preparation of the chiral monolithic stationary phases along with brief discussion and perspective on the future development of chiral monolithic stationary phases in CEC and capillary LC.

Oxidized single-walled carbon nanotubes (o-SWNTs) were employed as the drug carriers to deliver the small molecules of Rhodamine123 (Rho123) into the K562 cells via physical adsorption. However, due to the fluorescence quenching of Rho123 on carbon nanotubes, the quantitative determination of Rho123 in cells is difficult. Based on the MEKC coupled with LIF detection, a quantitative approach was developed for the determination of Rho123 delivered into K562 cells by o-SWNTs. Where the adsorbed Rho123 on o-SWNTs could be desorbed by SDS in running buffer and be simultaneously separated with o-SWNTs due to the differences of their electrophoretic mobility by applying the electric potential at the both ends of capillary. Using this approach, the intracellular uptakes of Rho123 in multidrug-resistant and multidrug-sensitive leukemia cells were quantified, and the results showed that o-SWNTs could be used as the potential drug carriers to deliver small molecules into cells via the physical adsorption along with the circumventing of multidrug resistance of leukemia cells.

A hydrophilic chiral capillary monolithic column for enantiomer separation in CEC was prepared by coating cellulose tris(3,5-dimethylphenyl-carbamate) (CDMPC) on porous hydrophilic poly(acrylamide-co-N,N'-methylene-bisacrylamide) (poly(AA-co-MBA)) monolithic matrix with confine of a fused-silica capillary. The coating conditions were optimized to obtain a stable and reproducible chiral stationary phase for CEC. The effect of organic modifier of ACN in aqueous mobile phase for the enantiomer separation by CEC was investigated, and the significant influence of ACN on the enantioresolution and electrochromatographic retention was observed. Twelve pairs of enantiomers including acidic, neutral, and basic analytes were tested and nine pairs of them were baseline-enantioresolved with acidic and basic aqueous mobile phases. A good within-column repeatability in retention time (RSD = 2.4%) and resolution (RSD = 3.2%) was obtained by consecutive injections of a neutral compound, benzoin, on a prepared chiral monolithic column, while the between-column repeatability in retention time (RSD = 6.4%) and resolution (RSD = 9.6%) was observed by column-to-column examination. The prepared monolithic stationary phase showed good stability in either acidic or basic mobile phase.

Strain ZJB-063, a versatile nitrile-amide-degrading strain, was newly isolated from soil in this study. Based on morphology, physiological tests, Biolog and the 16S rDNA sequence, strain ZJB-063 was identified as Bacillus subtilis. ZJB-063 exhibited nitrilase activity without addition of inducers, indicating that the nitrilase in B. subtilis ZJB-063 is constitutive. Interestingly, the strain exhibited nitrile hydratase and amidase activity with the addition of epsilon-caprolactam. Moreover, the substrate spectrum altered with the alteration of enzyme systems due to the addition of epsilon-caprolactam. The constitutive nitrilase was highly specific for arylacetonitriles, while the nitrile hydratase/amidase in B. subtilis ZJB-063 could not only hydrolyze arylacetonitriles but also other nitriles including some aliphatic nitriles and heterocyclic nitriles. Despite comparatively low activity, the amidase of hydratase/amidase system was effective in converting amides to acids. The versatility of this strain in the hydrolysis of various nitriles and amides makes it a potential biocatalyst in organic synthesis.