This study aims to elucidate a novel mechanism for elevating the pH within the calicoblastic extracellular calcifying medium (pH) of corals and demonstrate the potential contribution of calcifying organisms to CO sequestration. Departing from traditional models that attribute the increase in pH primarily to H expulsion via Ca-ATPase, we emphasize the significant role of polyamines. These ubiquitous biogenic amines conveyed by calicoblastic cells through polyamine transporters demonstrate a remarkable affinity for CO. Their ability to form stable carbamate complexes is pivotal in facilitating carbonate ion transport, which is crucial for pH regulation and skeletal structure formation. In this study, a polyamine transporter inhibitor and a polyamine biosynthesis inhibitor in conjunction with the pH-sensitive probe 8-hydroxypyrene-1,3,6-trisulfonic acid (HPTS) were employed to monitor pH variations. Furthermore, FM1-43FX dye was utilized to delineate the extracellular calcifying medium (ECM), whereas calcein was applied to visualize paracellular gaps and ECM. These methodologies provide profound insights into the intricate structural and functional dynamics of coral spats calcification. Findings suggest a potential reconsideration of established models of marine calcification and highlight the necessity to reassess the role of marine calcifying organisms in the carbon cycle, particularly their influence on CO fluxes.

The current paper explores the performance, microstructure and environmental consequences of low-calcium fly ash-based geopolymer concrete compared to OPC-based concrete. The performance of the concrete is assessed based on strength, permeability, sulfate resistance, and acid attack. Two geopolymer mixes were designed by adjusting the binder dosage. The geopolymer concrete mixes achieved 11-16% higher strength than OPC-based concrete. However, increasing the binder dosage from 30 to 40% led to 5% reduction in strength at later ages. Geopolymer concrete demonstrated superior resistance to sulfate and acid attacks, as well as lower penetration depth and permeability coefficient compared to OPC-based concrete. Microstructural analysis was conducted using XRD and SEM techniques, identifying sodium aluminosilicate gel as the product formed during the polymerization process. The environmental impact was evaluated through a life cycle assessment using a cradle-to-gate approach. Geopolymer concrete requires 25-33% less energy and emits 14-28% less kg-CO eq. than OPC-based concrete. The production of OPC-based concrete had the greatest negative environmental impact, except in the categories of metal depletion (MDP) and ionizing radiation (IRP_HE). In geopolymer concrete, the use of alkaline activators accounted for higher energy consumption and accounted for 73-75% kg-CO eq. emissions. Overall, fly ash-based geopolymer concrete showed higher strength and excellent resistance to acid and sulfate attacks, along with a lower carbon footprint and energy consumption.

Composting is one of the effective environmental protection and sustainable measures for improving soil quality and increasing crop yield. However, due to the special physical and chemical properties of saline-sodic soil and the complex rhizosphere microecological environment, the potential mechanism of regulating plant growth after applying compost in saline-sodic soil remains elusive.

The mitochondrion of the deadliest human malaria parasite, is an essential source of cellular acetyl-CoA during the asexual blood-stage of the parasite life cycle. Blocking mitochondrial acetyl-CoA synthesis leads to a hypoacetylated proteome and parasite death. We previously determined that mitochondrial acetyl-CoA is primarily synthesized from glucose-derived pyruvate by α-ketoacid dehydrogenases. Here, we asked if inhibiting the import of glycolytic pyruvate across the mitochondrial inner membrane would affect acetyl-CoA production and, thus, could be a potential target for antimalarial drug development. We selected the two predicted mitochondrial pyruvate carrier proteins ( MPC1 and MPC2) for genetic knockout and isotopic metabolite tracing via HPLC-MS metabolomic analysis. Surprisingly, we observed that asexual blood-stage parasites could survive the loss of either or both MPCs with only minor growth defects, despite a substantial reduction in the amount of glucose-derived isotopic labelling into acetyl-CoA. Furthermore, genetic deletion of two additional mitochondrial carboxylic acid transporters - DTC (di/tricarboxylic acid carrier) and YHM2 (a putative citrate/α-ketoglutarate carrier protein) - only mildly affected asexual blood-stage replication, even in the context of MPC deficiency. Although we observed no added impact on the incorporation of glucose carbon into acetyl-CoA in these quadruple knockout mutants, we noted a large decrease in glutamine-derived label in tricarboxylic acid cycle metabolites, suggesting that DTC and YHM2 both import glutamine derivatives into the mitochondrion. Altogether, our results expose redundant routes used to fuel the blood-stage malaria parasite mitochondrion with imported carbon from two major sources - glucose and glutamine.

Efficient detection of chloramphenicol (CAP) in the environment and food products is crucial for addressing global health and environmental safety concerns. This study presents the development of a cost-effective hybrid electrocatalyst comprising lignocellulosic carbon sheets, graphene oxide, and manganese oxide (LCSs/GO@MnO) for CAP detection using a simple electrochemical sensor fabricated on a glassy carbon electrode (GCE) substrate. The synergistic interaction between LCSs, GO, and MnO enhance the electroactive surface area of GCE, facilitating effective dispersion and electrode modification. This composite material significantly improves electrical conductivity and provides numerous electroactive sites for electrochemical CAP detection via voltammetric techniques. The developed sensor demonstrates a rapid electron transfer rate, enhancing electrode sensitivity for CAP detection at a low overpotential (-0.5717 V) and an optimal pH (7.0). The sensor exhibits a wide linear range (0.017-477.247 μM), excellent sensitivity (105.22 μA μM cm), and a low limit of detection (1.2 nM) with enhanced charge carrier efficiency. Additionally, the sensor shows good cycle stability, reproducibility, selectivity, and trace-level CAP sensing applicability in food samples at a low cost. These features make the sensor a promising platform for monitoring antibiotics in various applications.

Evodiamine has been a promising lead structure with broad-spectrum antitumor activity. Druggability optimization is the most challenging part of evodiamine-based lead-to-candidate campaign. Amino acids as building blocks for conjugates are widely incorporated into approved drug and drug candidates, demonstrating highly attractive druggability. Herein, a series of evodiamine amino acid conjugates were designed and synthesized based on the evodiamine lead compound (±)-8b discovered in our previous work. The structure-activity relationship (SAR) studies culminated in the identification of a promising conjugate (-)-15h featuring a N-Boc-l-glutamine group and a chiral carbon atom (sinister), which exhibited nanomolar antiproliferative activity against LoVo and RKO colorectal cancer cells. Moreover, (-)-15h could inhibit topoisomerases I, arrest the cell cycle in the G2/M phase, and induce apoptosis. Importantly, (-)-15h (tumor growth inhibition rate was 82.53 % in 40 mpk) showed better efficacy and tolerability to that of parent compound (-)-8b (tumor growth inhibition rate was 51.22 % in 40 mpk) in LoVo xenograft model. Further, (-)-15h (tumor growth inhibition rate was 70.09 % in 40 mpk) showed comparable efficacy and better tolerability to that of topotecan (tumor growth inhibition rate was 70.67 % in 0.5 mpk) in HT-29 xenograft model. Collectively, this study further provided a strong scientific basis for amino acid-based structural modifications and a drug lead for anti-colorectal cancer applications.

Rubisco (ribulose 1,5-bisphosphate carboxylase/oxygenase) is the central enzyme for converting atmospheric CO into organic molecules, playing a crucial role in the global carbon cycle. In cyanobacteria and some chemoautotrophs, Rubisco complexes, along with carbonic anhydrase, are enclosed within specific proteinaceous microcompartments, known as carboxysomes. The polyhedral carboxysome shell ensures a dense packaging of Rubisco and creates a high-CO internal environment to facilitate the fixation of CO. Rubisco and carboxysomes have been popular targets for bioengineering, with the intent of enhancing plant photosynthesis, crop yields, and biofuel production. However, efficient generation of Form 1B Rubisco and cyanobacterial β-carboxysomes in heterologous systems remains challenging. Here, we developed genetic systems to efficiently engineer functional cyanobacterial Form 1B Rubisco in E. coli, by incorporating Rubisco assembly factor Raf1 and modulating the RbcL/S stoichiometry. We further accomplished effective reconstitution of catalytically active β-carboxysomes in E. coli with cognate Form 1B Rubisco by fine-tuning the expression levels of individual β-carboxysome components. In addition, we investigated the encapsulation mechanism of Rubisco into carboxysomes via constructing hybrid carboxysomes; this was achieved by creating a chimeric encapsulation peptide incorporating SSLDs that permits the encapsulation of Form 1B Rubisco into α-carboxysome shells. Our study provides insights into the assembly mechanisms of plant-like Form 1B Rubisco and its encapsulation principles in both β-carboxysomes and hybrid carboxysomes, and highlights the inherent modularity of carboxysome structures. The findings lay the framework for rational design and repurposing of CO-fixing modules in bioengineering applications, e.g. crop engineering, biocatalyst production, and molecule delivery.

Hemodialysis (HD) is a treatment with a significant environmental impact. One dialysis cycle is equivalent to the daily consumption of 3.5-4 people, and the average annual electricity consumption of a center is equivalent to that of approximately 2.5-3 households (9 kWh/day per household). The carbon footprint (kg CO2 equivalent) measures direct and indirect greenhouse gas emissions and is influenced by the production of the various materials used, their transport, patients, and healthcare personnel. In this context, it is necessary to understand the real impact of each center on the environment and act sustainably. The aim of this review is to analyze the environmental footprint generated by dialysis, rethink processes, and propose management strategies to provide tools applicable to any unit to reduce the negative impact of this activity. Each center must measure and monitor indicators, set its own standards, design improvement plans, and carry out annual monitoring in a multidisciplinary manner.

Microplastics (MPs) contamination is pervasive in agricultural soils, significantly influencing carbon and nitrogen biogeochemical cycles and altering greenhouse gas (GHG) fluxes. This review examines the sources, status, mechanisms, and ecological consequences of MPs pollution in agricultural soils, with a focus on how MPs modified soil physicochemical properties and microbial gene expression, ultimately impacting GHG emissions. MPs were found to reduce soil water retention, decreasing soil respiration and increasing emissions of CO, CH₄, and NO. They also enhanced soil aggregate stability and influenced soil organic carbon (SOC) sequestration, contributing further to GHG emissions. MPs-induced increases in soil pH were associated with suppressed CH₄ and NO emissions, whereas the abundance of genes encoding enzymes for cellulose and lignin decomposition (e.g., abfA and mnp) stimulated enzyme activity, intensifying NO release. Additionally, a reduced soil C/N ratio promoted denitrification processes. Changes in microbial communities, including increases in Actinomycetes and Proteobacteria, were observed, with a rise in genes associated with carbon cycling (abfA, manB, xylA) and nitrification-denitrification (nifH, amoA, nirS, nirK), further exacerbating CO and NO emissions. This review provides valuable insights into the complex roles of MPs in GHG dynamics in agricultural soils, offering perspectives for improving environmental management strategies.

Benthic dinoflagellates constitute a group of microalgae that inhabit the ocean floor, adhering to substrates such as coral, seagrasses, and sand. Certain species within this group have the potential to produce toxins. Ocean warming could increase the occurrence of harmful benthic dinoflagellate blooms, which pose a significant threat to coastal ecosystems in tropical and subtropical regions. However, the impact of water temperatures on the growth and toxicity of these harmful algal species remains uncertain. In this study, we investigated the physiological and transcriptional responses, as well as toxin production, of Gambierdiscus belizeanus, a common dinoflagellate responsible for increasing ciguatera risk, when exposed to temperatures ranging from 18 °C to 28 °C. Based on 70-day growth curves, G. belizeanus grew fastest at 26 °C, with a maximum specific growth rate of 0.088 ± 0.018 div·d. At stationary phase of algal cultures, the photosynthetic efficiency (Fv/Fm) of algal cells at 26 °C was the highest (0.56 ± 0.02) among all treatments; significant decreases in pigment contents, including chlorophyll a, chlorophyll c, and carotenoids, were observed in algal cells exposed to 18 °C. However, during the exponential phase, only algal cultures exposed to 22 °C exhibited significantly lower levels of chlorophyll a and photosynthetic efficiency. The levels of algal toxins (44-methylgambierone and gambierone) in the 18 °C and 22 °C groups were significantly higher than those in groups exposed to higher temperatures (26 °C and 28 °C). Transcriptomic analysis showed that improved growth and photosynthesis at higher temperatures (26 °C and 28 °C) corresponded with the increased activity of crucial genes in carbon metabolism and photosynthesis. These genes, essential for energy and growth, could potentially facilitate the spread of G. belizeanus blooms. Lower temperatures led to molecular adaptations in G. belizeanus, such as modulated cell cycle genes and suppressed photosynthesis, explaining the physiological changes observed. Furthermore, the activation of toxin production-related genes under lower temperatures suggests a potential risk to ecosystems due to bioaccumulation of toxins. This study elucidates the distinct cellular and molecular responses of harmful dinoflagellates to variations in seawater temperature. These findings enhance our understanding of the emerging threats that toxin-producing benthic dinoflagellates pose to coastal ecosystems. This concern is especially significant as ocean warming has enabled some benthic toxic dinoflagellates to extend their range into higher-latitude regions.