Taurine (TAU) has recently been found to have an impactful role in regulating plant responses under abiotic stresses. This study presented the comparative effects of TAU seed priming and foliar spray application on chickpea plants exposed to hexavalent chromium. Taurine priming and foliar applications (1.6 and 2.4 mM) notably modulated morpho-physiological and biochemical responses of plants under Cr(VI) stress. Plants subjected to 25 mg kg-1 soil Cr in the form of potassium dichromate (K2Cr2O7) displayed a significant reduction in growth, chlorophyll, and uptake of essential nutrients (N, K, P, and Ca). Cr(VI) toxicity also resulted in a notable increase in osmolyte accumulation, lipid peroxidation, relative membrane permeability, ROS generation, antioxidant enzyme activities, antioxidant compounds, endogenous Cr levels, and aerial Cr translocation. Taurine abridged lipoxygenase activity to diminish lipid peroxidation owing to the overproduction of ROS initiated by a higher Cr content. The acquisition and assimilation of essential nutrients were augmented by the TAU-related decrease in leaf and root Cr levels. Consequently, TAU enhanced growth by mitigating oxidative damage, reducing Cr content in the aerial parts, and reinforcing the activities of antioxidant enzymes. Compared to foliar spray, TAU seed priming has demonstrated superior efficacy in mitigating Cr phytotoxicity in plants.

Lead (Pb), a prevalent heavy metal contaminant in aquatic environments, has complex effects on the gut microbiome function of aquatic animals. In this study, metagenomic analysis of Bufo gargarizans tadpoles was carried out following Pb exposure. Moreover, histological analysis was performed on the intestines. The results showed that Pb exposure induced histological damage to the intestinal epithelium. Significant differences in microbial abundance and function were detected in the 200 mu g/L Pb group compared to the control group. Specifically, an increase in Bosea and Klebsiella was noted at 200 mu g/L Pb, which potentially could induce inflammation in tadpoles. Notably, the decrease in the abundance of glycoside hydrolases subsequent to exposure to 200 mu g/L Pb is likely to attenuate carbohydrate metabolism. Furthermore, increased fluoroquinolone-related antibiotic resistance genes (ARGs), phenolic-related ARGs, and iron uptake systems following 200 mu g/L Pb exposure might heighten the disease risk for tadpoles. These discoveries augment our comprehension of the influences of Pb on the intestinal well-being of amphibians and offer valuable insights for further assessment of the ecological risks that Pb poses to amphibians.

Cadmium (Cd) contamination in soil threatens global food production and human health. This study investigated zinc (Zn) addition as a potential strategy to mitigate Cd stress using two barley genotypes, Dong-17 (Cd-sensitive) and WSBZ (Cd-tolerant). Hydroponically grown seedlings were treated with different Cd (0, 1.0, 10 mu M) and Zn (0, 5, 50 mu M) levels. Results showed that Zn addition effectively alleviated Cd induced growth inhibition, improving SPAD values, photosynthetic parameters, fluorescence efficiency (Fv/Fm), and biomass. Zn reduced Cd contents in roots and shoots, inhibited Cd translocation, and ameliorated Cd induced ultrastructural damage to organelles. Transcriptomic analysis revealed distinct gene expression patterns between genotypes, with WSBZ showing enhanced expression of metal transporters, antioxidant defense, and stress signaling genes. Significantly, cell wall related pathways were upregulated in WSBZ, particularly lignin biosynthesis genes (PAL, C4H, 4CL, COMT, CAD/SAD), suggesting cell wall reinforcement as a key Cd tolerance mechanism. Zn induced upregulation of ZIP family transporters and downregulation of Cd transporters (HvHMA) aligned with reduced Cd accumulation. These findings provide comprehensive insights into molecular mechanisms of Zn mediated alleviation of Cd toxicity in barley, supporting improved agronomic practices for Cd contaminated soils.

Permafrost thaw represents one of Earth's largest climate feedback risks, potentially releasing vast carbon (C) stores as greenhouse gases (GHG). However, our ability to predict emissions remains limited by poor understanding of how changing organic matter (OM) composition affects microbial carbon processing. We test a metabolism-centered redox framework, which views microbial processes as coupled oxidative-reductive reactions, to mechanistically explain how organic matter metabolite quality controls greenhouse gas production in permafrost-affected peatland ecosystems. Rather than relying solely on geochemical redox measurements, our approach examines how microbes balance electron flow through metabolic pathways. Using active layer peat (9-19 cm) from contrasting environments (bog and fen), we employed multi-omics approaches, including metabolomics, metagenomics, and metatranscriptomics, to link OM chemistry to microbial function. Our results reveal distinct dissolved organic matter metabolite composition, with fen systems enriched in compounds with higher substrate quality (low molecular weight (MW) sugars with high H:C ratios and low aromaticity) and bog systems dominated by compounds with lower substrate quality (high MW phenols with lower H:C ratios and higher aromaticity). In fen samples, these sugar-like compounds correlated with higher oxidative metabolism and methanogenesis, supported by increased glycolysis gene expression. Initially, electrons from increased oxidative metabolism were balanced through nitrate and sulfate reduction, but as these electron acceptors were depleted, methanogenesis increased to maintain redox balance. Fen samples showed rapid degradation of both high- and low-substrate-quality compounds, suggesting sufficient energy for efficient C cycling. Conversely, bog samples exhibited more polyphenolic compounds, lower glycolysis activity, and higher stress-related gene expression, suggesting energy was diverted towards cell maintenance under acidic conditions rather than C processing. This approach suggests that predicting greenhouse gas emissions requires an understanding of how organic matter quality shapes microbial energy allocation strategies, providing a mechanistic framework for improving emission predictions from permafrost-affected peatlands and similar ecosystems.

The environmental prevalence of the tire wear-derived emerging pollutant N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine-quinone (6PPD-Q) has increasingly raised public concern. However, knowledge of the adverse effects of 6PPD-Q on soil fauna is scarce. In this study, we elucidated its impact on soil fauna, specifically on the earthworm Eisenia fetida. Our investigation encompassed phenotypic, multi-omics, and microbiota analyses to assess earthworm responses to a gradient of 6PPD-Q contamination (10, 100, 1000, and 5000 mu g/kg dw soil). Post-28-day exposure, 6PPD-Q was found to bioaccumulate in earthworms, triggering reactive oxygen species production and consequent oxidative damage to coelomic and intestinal tissues. Transcriptomic and metabolomic profiling revealed several physiological perturbations, including inflammation, immune dysfunction, metabolic imbalances, and genetic toxicity. Moreover, 6PPD-Q perturbed the intestinal microbiota, with high dosages significantly suppressing microbial functions linked to metabolism and information processing (P < 0.05). These alterations were accompanied by increased mortality and weight loss in the earthworms. Specifically, at an environmental concentration of 6PPD-Q (1000 mu g/kg), we observed a substantial reduction in survival rate and physiological disruptions. This study provides important insights into the environmental hazards of 6PPD-Q to soil biota and reveals the underlying toxicological mechanisms, underscoring the need for further research to mitigate its ecological footprint.

Excessive phosphorus emissions can result in the eutrophication of water bodies, causing severe environmental damage as well as influencing the efficiency of water treatment equipment. The impacts of carbon/phosphorus ratios on performance and mechanism of the upflow anaerobic sludge bed reactor remain unclear. Henrie, the effects of different carbon/phosphorus ratios (i.e., 80:1, 40:1, and 20:1) on the transformation of phosphorus in the biological treatment process of an upflow anaerobic sludge blanket (UASB) reactor were studied. The results showed that phosphines are of great importance in the phosphate reduction process. After a stable operation, the phosphine reached the highest 81.91 mg/m3 at a C/P ratio of 40:1. It was proved that the optimum operating condition of the reactor was carbon to phosphorus ratio of 40:1. Phosphate-reducing bacteria were present in the UASB reactor, and the relative abundance of Clostridia in the sludge was 1.90 % and 1.59 % when the C/P was 80:1 and 20:1, respectively. This implied that the low carbon to phosphorus ratio reduces the phosphorusreducing microbial activity in the reactor. Lower C/P values could inhibit the uptake and use of P in the phosphonate transport system and the transport of phosphate in the cell by the microbial Pst system, impeding the mineralization of organophosphates. The study provides new insights into improving the efficiency of treating phosphorus-rich wastewater.

A novel iron-based phosphate cement (IPC), derived from iron-rich smelting slag (ISS), was developed as a sustainable and efficient binder for the stabilization/solidification of trivalent chromium (Cr3+). The mechanical properties, hydration behavior, microstructure, leaching toxicity, chromium chemical forms, and environmental safety of chromium-stabilized iron phosphate cement (CIPC) were thoroughly evaluated. The results showed that, with a mass ratio of ISS to ammonium dihydrogen phosphate (ADP) of 2.0, and even with the addition of 20 % chromium nitrate nonahydrate (CN), the compressive strength of CIPC reached 4.2 MPa after curing for 28 d. Furthermore, chromium leaching was well below 1 mg/L, significantly lower than the GB 5085.3-2007 standard limit of 15 mg/L, demonstrating the effective encapsulation of Cr3+ due to IPC's high early strength. In the IPC system, Cr3+ was primarily stabilized by forming CrPO4 and CrxFe1-x(OH)3 co-precipitates, which were further solidified through the physical encapsulation of IPC hydration products, such as (NH4)2Fe(PO3OH)2 center dot 4H2O, (NH4) (Mg,Ca)PO4 center dot H2O, and FePO4. This process resulted in a solidification efficiency of up to 99 %. BCR analysis confirmed that more than 98 % of the chromium in the CIPC remained in a stable residual form. Finally, the ecological risk index (PERT) was found to be 23.52, far below the safety threshold of 150, indicating the solidified material's long-term environmental safety. This study provides an innovative approach for the reutilization of ISS while effectively stabilizing/solidifying chromium.

The recent combination of significantly reduced launch costs and the confirmed presence of water ice on the Moon presents new opportunities for lunar construction beyond the constraints of traditional In-Situ Resource Utilization (ISRU). This study investigates an alternative approach that incorporates Earth-supplied cement with lunar-derived resources to manufacture concrete directly on the lunar surface. In this concept, cement is transported from Earth, while lunar rocks are processed into aggregate and water ice is electrolyzed to provide the water and atmosphere necessary for concrete mixing. The resulting precast blocks are assembled into modular arch structures and covered with regolith for thermal and radiation protection. A comparative cost analysis shows that if launch costs fall from current levels (approximately US $1,410/kg) to projected levels under systems like Starship (US $10/kg), transportation costs for materials and equipment to build a habitat for two could drop from around US $138.6 million to just US $0.98 million. This roughly 99% reduction implies that conventional concrete-based construction may become economically viable for early lunar infrastructure. However, further research is needed in key areas such as performance of concrete structure under vacuum condition, in-situ water extraction efficiency, and optimization of regolith covering design.

Uranium/cadmium (U/Cd) pollution poses a significant global environmental challenge, and phytoremediation offers a sustainable solution for heavy metal contamination. However, the mechanisms by which plants survive U/Cd stress remain unclear. Here, we conducted soil culture experiments of moso bamboo seedlings under U/Cd stress (U, Cd and U + Cd) to examine the effects of it on plant growth, mineral metabolism, and rhizosphere micro-environment. Our findings reveal that U/Cd stress inhibits seedling growth, enhances reactive oxygen species damage, and bolsters the antioxidant system. Additionally, Partial Least Squares Path Modeling (PLS-PM) was employed to uncover potential tolerance mechanisms in moso bamboo under U/Cd stress. U/Cd is mainly distributed in the root cell walls and also exists predominantly in the residual state within the roots. Correspondingly, U and Cd significantly disrupt mineral metabolism in plant. Metabolomic analyses indicate that U/ Cd markedly suppress amino acid metabolism pathways, while they stimulate carbon metabolism to mitigate toxicity. Furthermore, U/Cd stress disrupts the rhizosphere microbial community structure, and the competitive interaction of nitrogen functions exists between rhizosphere microorganism and bamboo roots. PLS-PM reveal the U/Cd stress impacts the interaction of the soil-rhizosphere-plant system. Together, these findings offer new insights into the response mechanism of bamboo plants to heavy metal stress, and provide a theoretical foundation for screening heavy metal tolerant plants and managing mining areas.

Geopolymer concrete is a promising alternative to traditional cement due to its lower carbon footprint and enhanced mechanical properties. While carbonatogenic bacteria have been widely studied in Portland cement, their role in geopolymers remains underexplored, particularly in noncalcium precipitation mechanisms. This study screened limestone quarry samples using 16S amplicon sequencing to identify potential carbonatogenic bacteria. Following isolation and precipitation analysis, Lysinibacillus fusiformis JH2 was selected and incorporated into fly ash-bottom ash-based geopolymer paste. XRD and SEM analysis revealed that microbial carbonation led to the formation of aragonite, natrite, and brucite, refining pore structures, enhancing durability, and increasing compressive strength. Incorporating JH2 endospores significantly improved early strength, achieving 17.5 MPa within 7 days, meeting Indonesian structural standards, and increasing strength by up to 166 %. Notably, bacteria remained viable and retained their ability to form endospores, opening possibilities for endospore storage in artificial aggregates for selfhealing and bio-enhanced construction materials. These findings also show a potentially novel microbial pathway for non-calcium precipitation, contributing to the faster, more sustainable enhancement of geopolymer concrete for industrial applications.