ABSTRACTSpores of a hot spring isolated strain of Bacillus subtilis were tested as a biotechnological tool to be used for the detoxification and bioremedition of heavy metals. Lead and cadmium were efficiently adsorbed by B. subtilis spores with those of C1 more efficient than those of the lab collection strain PY79. Metal‐adsorption did not alter the functionality of C1 spores that were still fully resistant to heat, ethanol or chloroform and able to germinate after the interaction with Cd2+ or Pb2+. The spore‐adsorbed metals were released upon disruption of the spore coat layers, suggesting that the metals were mostly accumulated within the spore coat. Heat‐inactivated spores released almost all adsorbed metals, allowing the recovery of Cd2+ and Pb2+. While Cd2+ polluted water impaired the normal germination and growth of seeds of the model plant Arabidopsis thaliana, treatment of the polluted water with C1 spores restored plant growth.

Environmental imbalances caused by pollution and climate change has led to extreme erratic change in weather patterns and widespread ecosystem distress. In order to mitigate these imbalances, numerous sustainable methods have been adopted, among which microbial remediation strategy mediated through microbial enzymes holds significant promise. One such class of enzyme- laccase (EC 1.10.3.2) is known multicopper oxidase enzymes, naturally reported from bacteria, fungi, insects, plants can catalyze the oxidation of a wide range of phenolic and non-phenolic substrates by reducing molecular oxygen to water which imparts antioxidant properties to the enzyme, making it valuable in combating oxidative stress-a condition increasingly prevalent due to climate-induced environmental distress. The enzyme is also known for its multifarious applications of laccase, including heavy metal degradation and detoxification, decolorization of dyes, degradation of plastics, and optimization of food stability. The present review focuses on emphasising the role of laccase in improving the environmental health by balancing the oxidative status and remediation the pollutants.

Environmental Applications of Aspergillus oryzae: Keratinase Production for Sustainable Dehairing and Heavy Metal Detoxification

Emerging evidence suggests that endocrine-disrupting chemicals specifically heavy metals, may influence metabolic disorders including Type 1 Diabetes mellitus (T1DM). Poor glycaemic control is a key issue in management of T1DM. This cross-sectional study explores the association of toxic heavy metals with prevalence of T1DM and glycaemia. A total of 153 individuals with T1DM with mean age of 13 years and age- and sex matched 60 healthy controls from Coimbatore, South India were recruited. Clinical data including glycated haemoglobin and sociodemographic and environmental exposure data were collected. Urine samples were analysed for Copper (Cu), Zinc (Zn), Cadmium (Cd), Arsenic (As), Barium (Ba) and Lead (Pb), which are all known endocrine-disrupting chemicals. Urinary concentrations of all heavy metals were normalized to urine creatinine and expressed as ug/mg creatinine. The levels of all analyzed metals were significantly higher in T1DM compared to controls. Correlation analysis revealed the positive association between glycaemia and heavy metals. Arsenic and lead showed significant trend with T1D prevalence on comparison to control while zinc and cadmium showed significant trend with uncontrolled glycaemia. This study reveals the association of heavy metals exposure on the etiology and pathophysiology of T1DM. In addition, this study highlights the need of screening of urinary heavy metals as part of metabolic risk assessment and development of targeted therapies for heavy metal detoxification for achieving better glycaemia in T1DM.

MdPHR1 activates the antioxidant system, reduces the accumulation of reactive oxygen species, regulates the expression of genes related to heavy metal detoxification, and reduces plant sensitivity to zinc or cadmium. In the process of the rapid development of industrial and agricultural production, the excessive accumulation of cadmium (Cd) and zinc (Zn) in the soil seriously threatens the survival and development of plants and even endangers human health. Therefore, it is of great significance to explore new genes and mechanisms to regulate heavy metal tolerance in plants. We demonstrated that MdPHR1 (MYB-CC transcription factor) gene expression was markedly up-regulated after Zn or Cd treatment. Moreover, apple callus and transgenic Arabidopsis lines overexpressing MdPHR1 exhibited enhanced tolerance to Zn or Cd stress. The transgenic materials exhibited enhanced activity of essential antioxidant enzymes, including catalase (CAT), superoxide dismutase (SOD), and peroxidase (POD), accompanied by a significant decrease in reactive oxygen species (ROS) and malondialdehyde (MDA) levels. Additionally, enhanced biomass production and elevated chlorophyll levels were observed in the overexpression lines. Moreover, ectopic overexpression of MdPHR1 in Arabidopsis regulated the preserving structural expression of antioxidant synthesis-related genes and heavy metal detoxification-related genes, thereby increasing the activity of antioxidant enzymes and promoting the efflux of Zn or Cd ions. Thus, Zn- or Cd-induced phytotoxicity was significantly mitigated. Collectively, our results demonstrate that MdPHR1 functions as a key positive regulator in plant adaptation to Zn or Cd stress. These findings provide valuable insights for molecular breeding strategies designed to improve crop tolerance to heavy metal stress.

Environmental pollution arising from industrialization, agricultural intensification, and rapid urbanization remains a major ecological and public health concern. Persistent contaminants such as heavy metals, hydrocarbons, pesticides, plastics, and pharmaceutical residues accumulate in soil and water, disrupting ecosystems and threatening human well-being. Conventional remediation methods, including chemical treatments, incineration, and physical removal, often provide incomplete solutions due to high costs, partial pollutant removal, and the generation of secondary waste. Bioremediation offers a more sustainable alternative by harnessing microbial metabolism to degrade or detoxify pollutants. However, its efficiency is often limited by low pollutant bioavailability, slow degradation rates, and microbial sensitivity to toxic environments. Advances in nanotechnology have introduced engineered nanoparticles (ENPs) that can overcome these barriers through synergistic interactions with microorganisms. ENPs enhance pollutant solubilization, facilitate electron transfer, and improve microbial tolerance under stress, resulting in more efficient and adaptable remediation systems. This review synthesizes recent progress in nano–bio remediation, emphasizing applications in heavy metal detoxification, hydrocarbon degradation, wastewater treatment, and plastic biodegradation. It also critically examines nanoparticle toxicity, environmental persistence, cost implications, and regulatory uncertainties. Finally, the paper highlights future directions focused on biocompatible nanomaterials, engineered microbial strains, interdisciplinary collaboration, and circular economy integration to ensure the safe, scalable, and sustainable deployment of nano–bio remediation technologies.

Heavy metals are obnoxious pollutants that are detrimental to humans and other species and constitute a menace to the ecosystem's stability. The present study unravels the bioaccumulation efficacy of five microalgae, i.e., R1, H2, F1, Mg1, and M1 isolated from different agroclimatic zones of Punjab, India, for the heavy metal reduction in untreated domestic wastewater. Physicochemical analysis revealed that maximum reduction efficiency in BOD, COD, TDS, and electrical conductivity (EC) was obtained for the H2 consortium followed by R1 and Mg1. The isolation and physiological characterization of dominating photosynthetic organisms from each consortium unraveled their morphological and biochemical constitution. Furthermore, they were evaluated for heavy metal detoxification potential from untreated domestic wastewater by ICP-OES. The eukaryotic aseptate cylindrical filamentous isolate H2 (PP621793) has the highest capacity for remediating heavy metals. It showed a 50%, 50%, 40%, and 75% reduction in As, Cd, Ni, and Pb, respectively. A simultaneous study on heavy metal bioaccumulation recorded maximum biosorption in the biomass of the H2 isolate. Hence, this investigation reports the isolation of a novel microalga H2 from the Hoshiarpur district of the sub-mountain undulating zone of Punjab and underscores its potential for heavy metal detoxification from untreated domestic wastewater.

Evolutionary diversification and metal-specific roles of metallothioneins in Musca domestica: Insights from genomic and functional analyses.

BackgroundHeavy metals present in the environment, including lead, cadmium, and mercury, pose significant health risks to pregnant women and fetal development through food, water, and air contamination. Exposure to these metals has been linked to miscarriage, low birth weight (LBW), preterm birth, and developmental issues in children. The mechanism of oxidative stress, characterized by increased 8-hydroxy-2’-deoxyguanosine (8-OHdG) and malondialdehyde (MDA) levels, contributes to DNA damage, genomic instability, and adverse pregnancy outcomes. Additionally, DNA methylation changes induced by metal exposure may further exacerbate these risks. Certain micronutrients play a crucial role in heavy metal detoxification, and Moringa oleifera, a locally available plant rich in antioxidants and chelating compounds, has demonstrated protective effects against mercury (Hg), lead (Pb), and cadmium (Cd) toxicity in experimental studies. However, intervention studies on pregnant women remain scarce.ObjectiveThe objective of this study was to evaluate the effect of M. oleifera supplementation in reducing heavy metal toxicity and oxidative stress biomarkers, 8-OHdG and MDA, in pregnant women exposed to high levels of heavy metals.MethodsA quasi-experimental, nonrandomized pre-post test design is used. Pregnant women with elevated heavy metal levels, identified through initial screening, will be included in the intervention group, receiving M. oleifera supplementation for 2 months. The control group will consist of women from similar geographical regions who will not receive the intervention. Primary outcomes will include changes in heavy metal concentrations, measured using inductively coupled plasma mass spectrometry (ICP-MS). Secondary outcomes will focus on reductions in oxidative stress biomarkers, measured via enzyme-linked immunosorbent assay (ELISA). Statistical analyses, including analysis of covariance (ANCOVA), will be used to adjust for baseline differences between the groups.ResultsA total of 26 mothers for each group have participated. As of February 2025, the laboratory analyses have been ongoing, and the result is expected to be published at the end of 2025. The protocol anticipates that the intervention group will show a significant reduction in both heavy metal levels and oxidative stress biomarkers compared to the control group, suggesting the potential efficacy of M. oleifera in detoxifying heavy metals and reducing oxidative stress.ConclusionsThis study is expected to provide preliminary evidence on the potential effectiveness and safety of M. oleifera supplementation for reducing heavy metal toxicity and oxidative stress in pregnant women.

ABSTRACT Agricultural waste management is critical for reducing environmental pollution and enhancing soil health, particularly the treatment of organic waste containing heavy metals. This study investigates the distinct effects of mesophilic and thermophilic microbial inoculation on composting. Using rice straw and swine manure as feedstocks, composting piles were inoculated with mesophilic (Bacillus subtilis and Trichoderma reesei) or thermophilic (Geobacillus stearothermophilus and Aspergillus fumigatus) microorganisms, alongside a control group with no inoculation. The results revealed that thermophilic inoculation significantly enhanced organic degradation and humification, leading to more efficient stabilization of heavy metals such as Pb, Zn, and Cr, especially during the thermophilic and mature phases. Microbial community analysis showed that thermophilic inoculation created a more connected microbial network and boosted the microbial functionality. Spearman correlation analysis indicated that the enhanced key metabolic pathways of IT, particularly those involved in organic matter degradation and heavy metal detoxification, were associated with reduced metal bioavailability during thermophilic phase. These findings highlighting the potential of thermophilic inoculants for sustainable waste management and environmental protection.

Plasmid-mediated transmission can account for half of carbapenem-producing Enterobacterales (CPE) dissemination, underscoring the need to identify genetic determinants of plasmid persistence in the hospital setting. From 1,088 CPE isolates detected through nationwide surveillance in Singapore over five years, 1,115 closed carbapenemase-producing plasmids were identified and clustered, of which 92.5% (n = 1031) were grouped into 48 plasmid clusters (PCs). The most common plasmid genotypes were PC1 and PC2. Of 389 isolates carrying blaKPC-2-positive PC1 plasmids and 283 isolates carrying blaNDM-1-positive PC2 plasmids, 236 (60.7%) and 168 (59.4%) putatively acquired the carbapenemase gene via plasmid-mediated horizontal transmission, whereas 153 (39.3%) and 115 (40.6%) putatively acquired the carbapenemase gene via clonal lineage-dependent vertical transmission, respectively. Less abundant plasmids showed distinct inserted genomic regions encoding genes related to heavy metal and formaldehyde detoxification not found in predominant plasmids. Our data suggest that PC1 and PC2 genotypes are better adapted for stable propagation of blaKPC-2 and blaNDM-1, respectively, during inter-patient clonal spread and across multiple species (and sequence types) compared to other genetic settings. We propose that a crucial factor enabling evolutionarily successful carbapenemase plasmid genotypes to achieve hyperendemicity in the population is the maintenance of conserved genomes, thus minimizing fitness costs to their hosts.

The human microbiome is a diverse group of microbes that regulates the host's environment and health. Probiotic microorganisms improve gastrointestinal microbial balance. However, frequent exposure to heavy metals (HMs) such as arsenic, lead, cadmium, chromium and mercury can disrupt the delicate balance gut microbiota, altering its composition. Exopolysaccharide (EPS) from probiotics can effectively reduce HM toxicity and mobility in the environment, potentially enhancing the gut microbiota's ability to regulate the host's environment. The current paper discusses the role of probiotic supplementation on HM biosorption to build awareness about the health effects of HMs on human metabolism and raises concerns about their sources, distribution and the potential effects on human gut health. HM toxicity occurs through reactive oxygen species which can cause damage to cellular components such as DNA, proteins and lipids. This oxidative damage can lead to various health issues, including neurodegenerative diseases, cardiovascular problems and impaired immune function. EPS biopolymers have shown promising results in the removal of HMs from contaminated environments through binding with metal ions, preventing their harmful effects on living organisms. Thus, EPS biopolymers have been found to enhance the growth and activity of probiotic microorganisms, further aiding in the bioremediation process. Vigorous research is needed to understand the underlying mechanism and cell surface morphology of bacteria for better sorption and removal of HMs. © 2025 Society of Chemical Industry.

Heavy metal poisoning remains a critical public health issue worldwide, causing neurological, renal, and systemic damage. Dimercaprol (British Anti-Lewisite, BAL), developed during World War II as an antidote against arsenic and other toxic metals, continues to be clinically relevant due to its strong chelating properties. Despite its long history of use, detailed biochemical data on its metabolic degradation and fragmentation pathways remain scarce. This study aims to elucidate the gas-phase degradation mechanisms of BAL using experimental tandem mass spectrometry (MS/MS). MS/MS analyses were performed on a Shimadzu LCMS-8050 triple quadrupole equipped with electrospray ionization (ESI). Dimercaprol was directly infused at 0.1 mg/L, and precursor ions were fragmented via collision induced dissociation with argon. Collision energies ranged from 10 V to 50 V, and product ion spectra were acquired between 2 m/z–120 m/z. Spectral data were compared against predicted fragmentation patterns available in the Drug Bank database. Distinct collision energy-dependent fragmentation patterns were identified. At -10 V and -20 V, the ion m/z 107 ([C3H7S2]+) was predominant, while at -40V, fragments m/z 75 ([C3H7S]+) and m/z 61 ([C2H5S]+) were observed. These results diverged significantly (≥15% intensity differences) from Drug Bank simulations, highlighting the limitations of predictive models for organosulfur compounds. Thermochemical analysis indicated preferential stabilization of positive charge on sulfur centers, with reaction enthalpies between 221 kcal/mol–279 kcal/mol. A seven-step fragmentation pathway was proposed, leading to cyclic intermediates that explain BAL’s metabolic behavior. This study experimentally identified key fragmentation markers of dimercaprol (m/z 107, 75,61), providing robust fingerprints for its degradation. The discrepancies within in silico spectra emphasize the necessity of experimental validation, particularly for sulfur-containing pharmacological agents. These insights not only clarify BAL’s degradation pathways but also support the rational design of novel therapeutic derivatives for heavy metal detoxification.

IntroductionTo elucidate the physiological and molecular responses of peanut (Arachis hypogaea L L. c.v. ‘Haihua No. 1’) to copper stress, this study aimed to investigate the changes in root morphology, ion content, oxidative stress, and gene expression under copper stress conditions.MethodsSeedlings were exposed to 0 (control) or 50 mg/L CuSO₄ solution, with three biological replicates for each treatment. Root length and biomass were measured quantitatively, along with tissue contents of eight ions (K+, Na+, Mg2+, Ca2+, Fe3+, Mn2+, Cu2+, Zn2+), secondary oxidative stress indices, and activities of key antioxidant enzymes. RNA-seq and qPCR validation were performed to analyze transcriptional changes and identify specific gene-response modules in peanut seedling roots under copper stress.ResultsCopper stress significantly induced the expression of MPK4, a key component of the MPK4 pathway. Post-translationally, MPK4 likely phosphorylated two critical protein classes: NAC and LBD. NAC functioned as a core transcription factor, directly regulating the transcription of copper defense-related genes. LBD directly down-regulated genes associated with lateral root growth, indirectly promoting the expression of genes involved in GSH-dependent heavy metal detoxification and secondary oxidative stress (e.g., GST and POD), thereby enhancing the plant's detoxification and antioxidant capacity.DiscussionThis study provides insights into the regulatory mechanisms that peanut plants employ to cope with copper stress. The findings highlight the roles of MPK4, NAC, and LBD in the plant's response to copper stress and suggest that these genes could be targeted in breeding programs to develop copper-tolerant peanut cultivars. The results may provide theoretical support for the development of such cultivars.

Modern perspectives on chelation therapy: optimizing biochemical approaches to heavy metal detoxification

Bioremediation of heavy metal-contaminated sites is currently considered one of the most promising strategies for environmental remediation. Bacteria, with their simple structure and ease of modification, serve as ideal biological resources. Although numerous review studies have examined the mechanisms of microbial adsorption of heavy metals, most focus on macro-level processes. However, there is a lack of systematic research on how microorganisms respond to heavy metal stress and how their cellular components and metabolites in the adsorption and transport of heavy metals. In this review, we collected scientific information on bacterial-mediated bioremediation of heavy metals and conducted a comprehensive induction and analysis of it in combination with our own insights. The results showed that due to their structural composition, bacterial cell walls and membranes serve as barriers against heavy metal stress. Bacterial cells achieve heavy metal adsorption, detoxification, and transport through extracellular adsorption, intracellular chelation, and efflux. Specifically, extracellular adsorption involves ion exchange, complexation, redox reactions, nanoparticle formation, and biomineralization. Intracellular chelation is primarily mediated by bacterial metabolites such as metallothioneins and siderophores, while transport is mainly facilitated by components of efflux systems, including P-ATPases, CDF family proteins, and CBA transporters. This review aims to clarify patterns of organism-environment interactions, advance the development and application of heavy metal biosorbents, and further mitigate the risks of heavy metals to humans and the environment.

The eradication of heavy metal contamination has emerged as a paramount objective in preserving and conserving global water resources. The present study highlights the potential of halophilic fungal melanin derived from Curvularia lunata as an eco-friendly, cost-effective, highly stable, and efficient biosorbent for removing toxic heavy metals. UV and FTIR spectroscopy characterization confirmed the presence of functional groups typical of eumelanin. Particle size analysis revealed a notable reduction in size from unmodified melanin (54.22-87.94nm) to melanin nanoparticles (MNPs) (22.74-26.41nm), indicating improved surface area for adsorption. Inductively Coupled Plasma Mass Spectrometry (ICP-MS) data further validated the superior adsorption capabilities of MNPs compared to unmodified melanin. Specifically, the MNPs exhibited a 100% removal efficiency of over 18 metals out of 24 at a concentration of 0.15mg/L and at pH 7, surpassing the performance of native melanin. X-ray photoelectron spectroscopy (XPS) was applied to specify the elemental composition of the solid surfaces and the chemical forms of adsorbed metals. Ultrasound-assisted extraction (UAE) significantly enhances adsorption efficacy by facilitating better dispersion and generating a higher surface area, thereby increasing the Number of active binding sites available on MNPs for heavy metal chelation. This mycoremediation-based approach presents a scalable and industrially adaptable solution for water detoxification, offering an advantageous alternative to conventional high-performance membrane technologies with minimal process modifications.

Carbonaceous materials enhanced algal-bacterial biofilm systems for synergistic redox transformation of Cr(VI) and As(III): ROS-driven mechanism and microbial regulation.

Silicon's role in enhancing cadmium substitution for zinc in Thalassiosira weissflogii: implications for heavy metal detoxification in marine environments.

Enhanced electron transfer capacity in lignin-rich compost-derived dissolved organic matter: A comparison with protein-rich compost.