Uptake Process Research Articles

Unraveling Complexities in the Absorption and Disposition Kinetics of Abiraterone via Iterative PBPK Model Development and Refinement.

Abiraterone is a first-in-class inhibitor of cytochrome P450 17A1 (CYP17A1), and its pharmacokinetic (PK) profile is susceptible to intrinsic and extrinsic variabilities. Potential associations between abiraterone concentrations and pharmacodynamic consequences in prostate cancer may demand further dosage optimization to balance therapeutic outcomes. Consequently, we aim to develop a physiologically based pharmacokinetic (PBPK) model for abiraterone via a middle-out approach to prospectively interrogate the untested, albeit clinically relevant, scenarios. To characterize in vivo hydrolysis of prodrug abiraterone acetate (AA) and supersaturation of abiraterone, in vitro aqueous solubility data, biorelevant measurements, and supersaturation and precipitation parameters were utilized for mechanistic absorption simulation. CYP3A4-mediated N-oxidation and sulfotransferase 2A1-catalyzed sulfation of abiraterone were subsequently quantified in human liver subcellular systems. Iterative PBPK model refinement involved evaluation of potential organic anion transporting polypeptide (OATP)-mediated abiraterone uptake in transfected cells in the absence and presence of albumin. The developed PBPK model recapitulated the duodenal concentration-time profile of both AA and abiraterone after simulated AA administration. Our findings established abiraterone as a substrate of hepatic OATP1B3 to recapitulate its unbound metabolic intrinsic clearance. Further consideration of a transporter-induced protein-binding shift established accurate translational scaling factors and extrapolated the sinusoidal uptake process. Subsequent simulations effectively predicted the PK of abiraterone upon single and multiple dosing. Our systematic development of the abiraterone PBPK model has demonstrated its application for the prospective interrogation of the individual or combined influences of potential interindividual variabilities influencing the systemic exposure of abiraterone.

Transferrin receptor-targeting property of pabinafusp alfa facilitates its uptake by various types of human brain-derived cells in vitro

Pabinafusp alfa, which is an anti-mucopolysaccharidosis II drug, consists of iduronate-2-sulfatase (IDS) genetically fused with an anti-transferrin receptor (TfR) antibody. While IDS is known to enter cells via mannose-6-phosphate receptor (M6PR)-mediated endocytosis, the anti-TfR antibody moiety of pabinafusp alfa is supposed to trigger the TfR-mediated transcytosis involved in its blood-brain barrier (BBB) penetration to deliver IDS into the brain, which thus makes it effective for treatment of brain symptoms of the disease. However, since these uptake processes remain unexamined in vitro, this study aims at elucidating how human brain cells manipulate these receptors to facilitate pabinafusp alfa uptake. The results of pabinafusp alfa uptake assays showed that the TfR played an primary role in its uptake by brain microvascular endothelial cells. The TfR contribution was also found in neuronal cells at levels comparable to M6PR. Interestingly, the predominant roles of TfR over M6PR in pabinafusp alfa uptake were also observed in astrocytes and pericytes. To summarize, our results support the TfR-targeting strategy of pabinafusp alfa for facilitating its BBB penetration while simultaneously identifying previously unnoticed TfR roles in its uptake into human neuronal and non-neuronal brain cells. These findings are certain to provide important insights into the mechanisms behind clinical actions of pabinafusp alfa.

Endocytic pathways of pathogenic protein aggregates in neurodegenerative diseases.

Endocytosis is the fundamental uptake process through which cells internalize extracellular materials and species. Neurodegenerative diseases (NDs) are characterized by a progressive accumulation of intrinsically disordered protein species, leading to neuronal death. Misfolding in many proteins leads to various NDs such as Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), amyotrophic lateral sclerosis (ALS) and other disorders. Despite the significance of disordered protein species in neurodegeneration, their spread between cells and the cellular uptake of extracellular species is not entirely understood. This review discusses the major internalization mechanisms of the different conformer species of these proteins and their endocytic mechanisms. We briefly introduce the broad types of endocytic mechanisms found in cells and then summarize what is known about the endocytosis of monomeric, oligomeric and aggregated conformations of tau, Aβ, α-Syn, Huntingtin, Prions, SOD1, TDP-43 and other proteins associated with neurodegeneration. We also highlight the key players involved in internalizing these disordered proteins and the several techniques and approaches to identify their endocytic mechanisms. Finally, we discuss the obstacles involved in studying the endocytosis of these protein species and the need to develop better techniques to elucidate the uptake mechanisms of a particular disordered protein species.

Alleviation of chromium stress in plants using metal and metal oxide nanoparticles.

Chromium (Cr), one of the hazardous pollutants, exists predominantly as Cr(VI) and Cr(III) in the environment. Cr(VI) is more toxic than Cr(III) due to its high mobility and solubility. Elevated levels of Cr in agricultural soil due to various anthropogenic activities cause Cr accumulation in plants, resulting in a significant reduction in plant yield and quality due to Cr-induced physiological, biochemical and molecular alterations. It can infiltrate the food chain through crop plants and cause harmful effects in humans via biomagnification. Cr(VI) is linked to cancer in humans. Therefore, mitigation strategies are required to remediate Cr-polluted soils and limit its accumulation in plants for safe food production. Recent research on metal and metal oxide nanoparticles (NPs) has shown that they can effectively reduce Cr accumulation and phytotoxicity. The effects of these NPs are influenced by their type and dose, exposure method, plant species and experimental settings. In this review, we present an up-to-date compilation and comprehensive analysis of the existing literature regarding the process of uptake and distribution of Cr and impact and potential mechanisms of metal and metal oxide nanoparticles led mitigation of Cr-induced stress in plants. We have also discussed recent developments, existing research gaps and future research directions in the field of Cr stress mitigation by NPs in plants. Overall, this review can provide valuable insights in reducing Cr accumulation and toxicity using metal and metal oxide nanoparticles, thereby promoting safe and sustainable cultivation of food and phytostabilization of Cr-polluted soil.

PTEN: The Potential Therapeutic Target of Diabetes Mellitus

Diabetes mellitus is a metabolic disease characterized by high blood glucose levels. The cause of glucose control failure is decreased insulin production by pancreatic β-cells and insulin resistance. Both lead to the obstacle of glucose uptake into cells. The mechanism of glucose uptake into cells is crucial in carbohydrate metabolism. This mechanism aims to produce energy in the form of ATP. The main signaling pathway after the process of glucose uptake is the PI3K/Akt pathway. This pathway involves many proteins activated by phosphorylation mechanisms. One of the proteins involved in this pathway is PTEN, a PI3K regulator. PTEN activity can dephosphorylate PI3K so that the insulin signaling pathway becomes blocked and glucose cannot be uptaken into cells. It causes blood glucose levels to increase. The role of PTEN in inhibiting the PI3K/Akt pathway seems to be a crucial matter to observe. By inhibiting PTEN activity, the insulin signaling pathway is expected to work properly. We have searched, read, analyzed, and summarized various studies regarding the potential of PTEN to reduce diabetes mellitus cases. In some research articles, the use of active compounds and therapy using stem cells to inhibit PTEN activity has shown good progress in the insulin signaling pathway. Based on these, it can be an option to make PTEN a target for diabetes mellitus therapy.

Environmentally relevant doses of endocrine disrupting chemicals affect male fertility by interfering with sertoli cell glucose metabolism in mice

The growing global deterioration in several aspects of human health has been partly attributed to hazardous effects of endocrine-disrupting chemicals (EDCs) exposure. Therefore, experts and government regulatory agencies have consistently advocated for studies on the combined effects of EDCs that model human exposure to multiple environmental chemicals in real life. Here, we investigated how low concentrations of bisphenol A (BPA), and phthalates compounds affect the Sertoli cell glucose uptake/lactate production in the testis and male fertility. An EDC mixture containing a detected amount of each chemical compound in humans, called daily exposure (DE), and DE increased in magnitude by 25 (DE25), 250 (DE250), and 2500 (DE2500), and corn oil (control) were administered for six weeks to male mice. We found that DE activated estrogen receptor beta (Erβ) and glucose-regulated protein 78 (Grp 78) and disrupted the estradiol (E2) balance. In addition, DE25, DE250, and DE2500 doses of the EDC mixture via binding with Sertoli cells’ estrogen receptors (ERs) inhibited the glucose uptake and lactate production processes by downregulating glucose transporters (GLUTs) and glycolytic enzymes. As a result, endoplasmic reticulum stress (ERS), marked by unfolded protein response (UPR) activation, was induced. The accompanying upregulation of activating transcription factor 4 (ATF4), inositol requiring enzyme-1 (IRE1), C/EBP homologous protein (CHOP), and mitogen-activated protein kinase (MAPK) signaling promoted antioxidant depletion, testicular cell apoptosis, abnormal regulation of the blood−testis barrier, and decreased sperm count. Therefore, these findings suggest that human and wildlife exposure to multiple environmental chemicals can produce a wide range of reproductive health complications in male mammals.

Characterization of chemical transport in human skin and building material

Volatile organic compounds (VOCs) and semi-volatile organic compounds (SVOCs) are ubiquitous in indoor environment. They can emit from source into air, and subsequently penetrate human skin into blood through dermal uptake, causing adverse health effects. This study develops a two-layer analytical model to characterize the VOC/SVOC dermal uptake process, which is then extended to predict VOC emissions from two-layer building materials or furniture. Based on the model, the key transport parameters of chemicals in every skin or material layer are determined via a hybrid optimization method using data from experiments and literature. The measured key parameters of SVOCs for dermal uptake are more accurate than those from previous studies using empirical correlations. Moreover, the association between the absorption amount of studied chemicals into blood and age is preliminarily investigated. Further exposure analysis reveals that the contribution of dermal uptake to the total exposure can be comparable with that of inhalation for the examined SVOCs. This study makes the first attempt to accurately determine the key parameters of chemicals in skin, which is demonstrated to be critical for health risk assessment.

Enhancement of adsorptive removal efficiency of an anionic dye from aqueous solutions using carboxylic acid-modified mulberry leaves: Artificial neural network modeling, isotherm, and kinetics evaluation.

Natural mulberry leaves and carboxylic acid-modified mulberry (Morus alba L.) leaves were used for the first time to scrutinize the effects of modification on the retention efficiency of an anionic dye (Remazol Brilliant Blue R (RBBR)) from aqueous solutions to suggest an economical and promising adsorbent for the treatment of dye-contaminated water. The characterization of the adsorbents was accomplished through common techniques including SEM, FTIR, and pHpzc determination. Several parameters studied in batch experiments pointed out that the initial pH of 2.0 and the contact time of 240 min were optimum conditions for all the developed RBBR uptake processes. An artificial neural network (ANN) model was applied to formulate a forecast model for the uptake efficiency of RBBR. The experimental data were assessed by different kinetic and isotherm models to explain the mechanism of the developed processes in more detail. Maximum monolayer adsorption capacities of natural mulberry leaves and acetic acid-, citric acid-, and oxalic acid-modified mulberry leaves were determined as 64.5, 95.2, 84.8, and 91.7 mg g-1, respectively, by the Langmuir isotherm model. These results demonstrated that the modification with carboxylic acids significantly increases the anionic dye adsorption capacity of the mulberry leaves.

Unravelling the metal uptake process in mosses: Comparison of aquatic and terrestrial species as air pollution biomonitors

Transplanted mosses have been widely shown to be excellent tools for biomonitoring air pollution; however, it is not clear how the functional groups present on their surfaces affect the uptake of metal cations. In the present study, we examined differences in trace metal accumulation in two terrestrial and one aquatic moss species, and investigated whether the differences depended on their physico-chemical characteristics. In the laboratory, we determined C, N and H contents in their tissues and obtained the ATR-FTIR spectra (to identify the presence of functional groups). We also conducted surface acid-base titrations and metal adsorption assays with Cd, Cu and Pb. In the field, we exposed transplants of each species near different air-polluting industries, and determined the mosses enrichment of Al, Cd, Co, Cr, Cu, Fe, Ni, Pb and V. Laboratory results demonstrated higher metal uptake capacity in the terrestrial mosses Sphagnum palustre and Pseudoscleropodium purum, compared to that in the aquatic moss Fontinalis antipyretica, which can be attributed to a greater abundance of acidic functional groups (i.e. negatively charged binding sites) on the surface of the terrestrial mosses. The affinity of moss for certain elements depends on the abundance and nature of surface functional groups. Accordingly, the metal concentrations generally reached higher levels in S. palustre transplants compared to the other species, except for the uptake of Hg, which was higher in F. antipyretica. However, the findings also suggest an interaction between the type of environment (terrestrial or aquatic) and the moss characteristics that may influence the abovementioned trend. Thus, irrespective of the physico-chemical characteristics, metal uptake varied depending on the environment of origin of the mosses “i.e. atmospheric or aquatic”. In other words, the findings suggest that species that accumulate more metals in terrestrial environments will accumulate lower amounts of metals in aquatic environments and vice versa.

Removal of benzotriazole micropollutants using Spirodela polyrhiza (L.) Schleid. And Azolla caroliniana Willd

Phytoremediation of benzotriazoles (BTR) from waters by floating macrophytes is not well understood, but it seems to have the potential to be used in conjunction with conventional wastewater treatment plants. The effectiveness of removing four compounds from the benzotriazole group by floating plants Spirodela polyrhiza (L.) Schleid. And Azolla caroliniana Willd. From the model solution, was studied. The observed decrease in the concentration of studied compounds was in the range 70.5%–94.5% using S. polyrhiza, and from 88.3% to 96.2% for A. caroliniana. It was determined using chemometric methods that the effectiveness of the phytoremediation process is mainly influenced by three parameters: exposure time to light, pH of the model solution and the mass of plants. Using the design of experiments (DoE) chemometric approach, the optimal conditions for removing BTR were selected: plant weight 2.5 g and 2 g, light exposure 16 h and 10 h, and pH 9 and pH 5 for S. polyrhiza and A. caroliniana, respectively. Studies on the mechanisms of BTR removal have shown that the reduction in concentration is mainly due to the process of plant uptake. Toxicity studies have proved that the tested BTR affected the growth of S. polyrhiza and A. caroliniana and induced changes in the levels of chlorophyllides, chlorophylls as well as carotenoids. More dramatic loss in plant biomass and photosynthetic pigment contents was observed in A. caroliniana cultures exposed to BTR.

Obesity-induced metabolic imbalance allosterically modulates CtBP2 to inhibit PPAR-alpha transcriptional activity

Maintenance of metabolic homeostasis is secured by metabolite-sensing systems, which can be overwhelmed by constant macronutrient surplus in obesity. Not only the uptake processes but also the consumption of energy substrates determine the cellular metabolic burden. We herein describe a novel transcriptional system in this context comprised of peroxisome proliferator-activated receptor alpha (PPARα), a master regulator for fatty acid oxidation, and C-terminal binding protein 2 (CtBP2), a metabolite-sensing transcriptional co-repressor. CtBP2 interacts with PPARα to repress its activity, and the interaction is enhanced upon binding to malonyl-CoA, a metabolic intermediate increased in tissues in obesity and reported to suppress fatty acid oxidation through inhibition of carnitine palmitoyltransferase 1 (CPT1). In line with our preceding observations that CtBP2 adopts a monomeric configuration upon binding to acyl-CoAs, we determined that mutations in CtBP2 that shift the conformational equilibrium toward monomers increase the interaction between CtBP2 and PPARα. In contrast, metabolic manipulations that reduce malonyl-CoA decreased the formation of the CtBP2/PPARα complex. Consistent with these in vitro findings, we found that the CtBP2/PPARα interaction is accelerated in obese livers while genetic deletion of CtBP2 in the liver causes derepression of PPARα target genes. These findings support our model where CtBP2 exists primarily as a monomer in the metabolic milieu of obesity to repress PPARα, representing a liability in metabolic diseases that can be exploited to develop therapeutic approaches.

Hydrogen Release and Uptake of MgH2 Modified by Ti3CN MXene

MgH2 has a high hydrogen content of 7.6 wt% and possesses good reversibility under normal conditions. However, pristine MgH2 requires a high temperature above 300 °C to release hydrogen, with very slow kinetics. In this work, we utilized Ti3CN MXene to reduce the operating temperature and enhance the kinetics of MgH2. The initial temperature of MgH2 decomposition can be lowered from 322 °C for pristine MgH2 to 214 °C through the employment of Ti3CN. The desorbed MgH2 + 7.5 wt% Ti3CN can start absorption at room temperature, while the desorbed pristine MgH2 can only start absorption at 120 °C. The employment of Ti3CN can significantly improve the hydrogen release kinetics of MgH2, with the desorption activation energy decreasing from 121 to 80 kJ mol−1. Regarding thermodynamics, the desorption enthalpy changes of MgH2 and MgH2 + 7.5 wt% Ti3CN were 79.3 and 78.8 kJ mol−1, respectively. This indicates that the employment of Ti3CN does not alter the thermal stability of MgH2. Phase evolution studies through the use of X-ray diffraction and electron diffraction both confirm that Ti3CN remains stable during the hydrogen release and uptake process of the composite. This work will help understand the impact of a transition metal carbonitride on the hydrogen storage of MgH2.

Intracellular Drug Delivery Process of Am80-Encapsulated Lipid Nanoparticles Aiming for Alveolar Regeneration.

Chronic obstructive pulmonary disease (COPD) results in obstructive ventilatory impairment caused by emphysema, and current treatment is limited to symptomatic therapy or lung transplantation. Therefore, the development of new treatments to repair alveolar destruction is especially urgent. Our previous study revealed that 1.0 mg/kg of synthetic retinoid Am80 had a repair effect on collapsed alveoli in a mouse model of elastase-induced emphysema. From these results, however, the clinical dose calculated in accordance with FDA guidance is estimated to be 5.0 mg/60 kg, and it is desirable to further reduce the dose to allow the formulation of a powder inhaler for clinical application. To efficiently deliver Am80 to the retinoic acid receptor in the cell nucleus, which is the site of action, we focused on SS-cleavable proton-activated lipid-like material O-Phentyl-P4C2COATSOME®SS-OP, hereinafter referred to as "SS-OP"). In this study, we investigated the cellular uptake and intracellular drug delivery process of Am80-encapsulated SS-OP nanoparticles to elucidate the mechanism of Am80 by nanoparticulation. Am80-encapsulated SS-OP nanoparticles were taken up into the cells via ApoE, and then Am80 was efficiently delivered into the nucleus via RARα. These results indicated the usefulness of SS-OP nanoparticles as drug delivery system carriers of Am80 for COPD treatment.

In situ synthesis of multivariant zeolitic tetrazolate imidazole frameworks (ZTIFs) with uncoordinated N-heteroatom sites for efficient adsorption of antiviral drugs

The current outbreak of the coronavirus (COVID-19) pandemic has significantly increased the global usage of antiviral drugs (AVDs), leading to higher concentrations of antibiotics in water pollution. To address this current issue, a new kind of adsorbent named isostructural zeolitic tetrazolate imidazolate frameworks (ZTIFs) were synthesized by combining imidazole and tetrazolates into one self-assembly approach by adjusting pores and stability of frameworks. The incorporation of imidazole ligand progressively increased the stability of frameworks. Furthermore, increasing the content of tetrazolate ligand greatly improved the adsorption performance due to N-rich sites by increasing the pore size. The obtained adsorbent composite exhibits macroporous structure up to 53.05 nm with excellent structural stability. Owing to their macropores and highly exposed active sites, the synthesized ZTIFs exhibit the maximum adsorption capacity for oseltamivir (OT) and ritonavir (RT) of 585.2 mg/g and 435.8 mg/g, respectively. Moreover, the adsorption uptake and saturation process were rapid compared to simple MOF. Within 20 min, both pollutants achieved equilibrium. The adsorption isotherms were best interpreted by Pseudo second order kinetics. The adsorption of AVDs on ZTIFs was spontaneous, exothermic, and thermodynamically feasible. The DFT calculations and characterization results after adsorption demonstrate that π-π interaction, pore filling, surface complexation, and electrostatic interaction were the primary features of the adsorption mechanism. The prepared ZTIFs composite exhibits high chemical, mechanical and thermal stability and can be recycled multiple times without destroying its morphology and structure. The adsorbent regeneration for several cycles impacted the operational cost and the eco-friendly characteristic of the process.

Transcriptomic and metabolic studies on the role of inorganic and organic iodine compounds in lettuce plants

Iodine (I) is considered a beneficial element or even micronutrient for plants. The aim of this study was to determine the molecular and physiological processes of uptake, transport, and metabolism of I applied to lettuce plants. KIO3, KIO3 + salicylic acid, 5-iodosalicylic acid and 3,5-diiodosalicylic acid were applied. RNA-sequencing was executed using 18 cDNA libraries constructed separately for leaves and roots from KIO3, SA and control plants. De novo transcriptome assembly generated 1937.76 million sequence reads resulting in 27,163 transcripts with N50 of 1638 bp. 329 differentially expressed genes (DEGs) in roots were detected after application of KIO3, out of which 252 genes were up-regulated, and 77 were down-regulated. In leaves, 9 genes revealed differential expression pattern. DEGs analysis indicated its involvement in such metabolic pathways and processes as: chloride transmembrane transport, phenylpropanoid metabolism, positive regulation of defense response and leaf abscission, and also ubiquinone and other terpenoid-quinone biosynthesis, protein processing in endoplasmic reticulum, circadian rhythm including flowering induction as well as a putative PDTHA (i.e. Plant Derived Thyroid Hormone Analogs) metabolic pathway. qRT-PCR of selected genes suggested their participation in the transport and metabolism of iodine compounds, biosynthesis of primary and secondary metabolites, PDTHA pathway and flowering induction.

Modulation effects of different dissolved nitrogen compositions on the phytoplankton community structure based on combined field experiments and the NbPD model in Jiaozhou Bay

The dissolved nitrogen (DN) regime in Jiaozhou Bay (JB) has shifted recently, and the phytoplankton community structure showed decreased diatom and increased dinoflagellate concentrations. This study combined field microcosm experiments, the Nutrients–bi-Phytoplankton–Detritus (NbPD) biogeochemical model, and statistical analysis, and obtained some results. The growth/death of dominant phytoplankton populations were comprehensively determined by the processes of nutrient uptake, excretion and decomposition of phytoplankton in JB. Kinetic parameters indicated that Skeletonema costatum preferentially absorbed NH4-N and NO3-N, while Protoperidinium pellucidum preferentially absorbed domestic-derived dissolved organic nitrogen. Moreover, S. costatum, as R-strategists, needed a faster uptake rate and slower excretion rate to achieve high growth efficiency but with faster decomposition, while P. pellucidum, as K-strategists, could maintain stability with a more active metabolism. Overall, this study discussed the key factors modulating the diatom dinoflagellate community structure changes in JB, providing a scientific basis for ecosystem-based management.

Investigation on Regulating Porous Polymers with Suitable Porosities and/or N-Doping for Enhanced CO2 Capture

Various cost-effective polycyclic aromatic hydrocarbons (PAHs) were used to fabricate hyper-cross-linked polymers (HCLPs) via an external cross-linker knitting method (ECLKM) followed by N-source impregnation modification. Multiple characterization techniques and thorough tests confirmed that the resultant thermally stable materials featured large specific surface areas (up to 2870 m2 g–1), narrow pore distributions (<0.70 nm), and high pore volumes (up to 1.09 cm3/g). Effects of porosities and N-doping modification ways on HCLPs’ CO2 capture capacities have been fully studied via controlling experiments. Remarkably, HCLP 1 prepared using naphthalene without further modification possessed the highest CO2 uptake capacity (up to 3.8 mmol g–1), indicating that porosities dominated the CO2 uptake process of HCLPs compared with N-doping modification. This study offers a facile strategy to construct HCLPs with great CO2 capture performances using PAHs via a simple one-pot ECLKM.

Mechanisms of extracellular photoelectron uptake by a Thiobacillus denitrificans-cadmium sulfide biosemiconductor system

The excellent performance of biosemiconductors in solar energy conversion and environmental remediation has triggered an explosive research in recent years. However, there is still a lack of knowledge on the mechanisms of extracellular photoelectron uptake in biosemiconductors, especially for the denitrifier-based one. Herein, a model biosemiconductor, Thiobacillus denitrificans-cadmium sulfide (T. denitrificans-CdS), for photoelectrotrophic denitrification was used to investigate the mechanism. Electrochemical characterization demonstrated more redox species generation after exposing T. denitrificans-CdS to light than the controls. Photoelectron uptake process was in situ recorded by an ITO-bottom electrochemical reactor. UV–Vis spectroscopy assured more outer-membrane cytochrome c generation and its concentration was 3.35 times higher in the light than that at dark. A coupled technology of SDS–PAGE, heme staining and LC–MS/MS targeted periplasmic cytochrome c4 (Cyt c4) emerging in T. denitrificans-CdS (light). Moreover, the expression of the cyt c4 gene was significantly (p < 0.05) upregulated under light, and its abundance increased from 1.2 ± 0.3 to 4.7 ± 1.2 folds with light intensity changing from 0.5 to 2.0 mW cm−2, supporting its role in the photoelectron uptake process. This work revealed the photoelectron uptake mechanism in T. denitrificans-CdS, and the results will provide guidance for constructing an efficient biosemiconductor system for nitrate removal and conversion driven by light.

Fe(III) induced synthesis of mesoporous tannic acid-based host–guest complex and its favorable nature towards Congo red removal

Tannic acid-based composites are a crop of promising mussel-inspired adsorbents to remediate toxic contaminants in wastewater. This work innovatively fabricated tannic acid-based host–guest complex for Congo red (CR) removal from simulated solution, via Fe(III) refining the poly(tannic acid-1,6-hexamethylenediamine) (PTHA) resin. Highly dispersed Fe/PTHA complex was endowed larger superficial area (50.41 m2 g−1) and mesoporosity (23.39 nm) than pure PTHA due to the reinvented physical crosslinking framework accompanied by the conversion of Fe(III) to Fe(II). The microstructure and composition of Fe/PTHA composites were confirmed by TEM, SEM, EDS, BET, XPS etc. The adsorption behavior of Fe/PTHA-4 was well interpreted by the pseudo-second-order kinetic model and Langmuir model that established its saturated adsorption capacity of 588.24 mg g−1. Meanwhile, the process of CR uptake was spontaneous and endothermic, which presented a rate-limiting step, and the removal mechanism might be attributed to the effects of electrostatic attraction, hydrogen bond, π–π stack, and pore filling. These results suggest the reusable Fe/PTHA-4 host–guest composite is a promising candidate for the CR elimination in water body.

Dissecting the metal resistance genes contributed by virome from mining-affected metal contaminated soils

Virus-borne auxiliary genes have been demonstrated to influence their hosts’ characteristics and flexibility, resulting in an elevated ability to withstand diverse conditions and competition. However, the research on the soil viral community and its influencing factors is not extensive. The effects of bacterium-phage co-evolution in the metal contaminated environment have yet to be fully understood. In our research, numerous viral genes with conserved functional residues/motifs working on detoxifying heavy metals were pinpointed in the virome recovered from 58 contaminated soil metagenomic samples of mineral area, including tellurite resistance genes (e.g., terC, terD), copper resistance genes (e.g., copC, copA), and arsenate resistance genes (e.g., arsC). Moreover, viral proteins involved in key processes of nutrient uptake and metabolism, cellular function, polysaccharides production and biomineralization were also detected, which may also contribute to the response of microbial community to heavy metal stress. Our research showed that viruses have helped their hosts to acquire novel metal-resistance abilities through horizontal gene transfer (HGT) during the adaptation to challenging metal-rich environments. This was also evidenced by the high Codon adaption index (CAI) values across metal-resistance-related genes. This study has advanced our understanding on virus-host interplay within heavy metal contaminated soils.