Autonomous Bionanorobots via a Cage-Shaped Silsesquioxane Vehicle for In Vivo Heavy Metal Detoxification.

Nanorobots hold great promise for integrated drug delivery systems that are responsive to molecular triggers. Herein, we successfully developed an automatic smart bionanorobot that has transport capability and recognizes and removes zinc ions from poisoned cells based on nanoscale polyhedral oligomeric silsesquioxane molecules. This intelligent bionanorobot can easily move inside and outside the cell and find zinc ions owing to its highly selective recognition to zinc ions and high cell permeability, especially the well-combined high penetration and strong binding energy. More importantly, it was also found that this intelligent bionanorobot can restore round HeLa cells to a normal fusiform cell morphology following high-concentration zinc treatment and does not interfere with cell proliferation and division. It was also shown by in vivo experiments that the bionanorobot can inhibit persistent enlargement of the liver caused by zinc ion poisoning.

Silymarin Dehydroflavonolignans Chelate Zinc and Partially Inhibit Alcohol Dehydrogenase.

Silymarin is known for its hepatoprotective effects. Although there is solid evidence for its protective effects against Amanita phalloides intoxication, only inconclusive data are available for alcoholic liver damage. Since silymarin flavonolignans have metal-chelating activity, we hypothesized that silymarin may influence alcoholic liver damage by inhibiting zinc-containing alcohol dehydrogenase (ADH). Therefore, we tested the zinc-chelating activity of pure silymarin flavonolignans and their effect on yeast and equine ADH. The most active compounds were also tested on bovine glutamate dehydrogenase, an enzyme blocked by zinc ions. Of the six flavonolignans tested, only 2,3-dehydroderivatives (2,3-dehydrosilybin and 2,3-dehydrosilychristin) significantly chelated zinc ions. Their effect on yeast ADH was modest but stronger than that of the clinically used ADH inhibitor fomepizole. In contrast, fomepizole strongly blocked mammalian (equine) ADH. 2,3-Dehydrosilybin at low micromolar concentrations also partially inhibited this enzyme. These results were confirmed by in silico docking of active dehydroflavonolignans with equine ADH. Glutamate dehydrogenase activity was decreased by zinc ions in a concentration-dependent manner, and this inhibition was abolished by a standard zinc chelating agent. In contrast, 2,3-dehydroflavonolignans blocked the enzyme both in the absence and presence of zinc ions. Therefore, 2,3-dehydrosilybin might have a biologically relevant inhibitory effect on ADH and glutamate dehydrogenase.

Biosorption of Zn(II) from Seawater Solution by the Microalgal Biomass of Tetraselmis marina AC16-MESO.

Biosorption refers to a physicochemical process where substances are removed from the solution by a biological material (live or dead) via adsorption processes governed by mechanisms such as surface complexation, ion exchange, and precipitation. This study aimed to evaluate the adsorption of Zn2+ in seawater using the microalgal biomass of Tetraselmis marina AC16-MESO "in vivo" and "not alive" at different concentrations of Zn2+ (0, 5, 10, and 20 mg L-1) at 72 h. Analysis was carried out by using the Langmuir isotherms and by evaluating the autofluorescence from microalgae. The maximum adsorption of Zn2+ by the Langmuir model using the Qmax parameter in the living microalgal biomass (Qmax = 0.03051 mg g-1) was more significant than the non-living microalgal biomass of T. marine AC16-MESO (Qmax = 0.02297 mg g-1). Furthermore, a decrease in fluorescence was detected in cells from T. marina AC16-MESO, in the following order: Zn2+ (0 < 20 < 5 < 10) mg L-1. Zn2+ was adsorbed quickly by living cells from T. marine AC16-MESO compared to the non-living microalgal biomass, with a decrease in photosystem II activities from 0 to 20 mg L-1 Zn2+ in living cells.

Adsorption of Zn2+ from Synthetic Wastewater Using Dried Watermelon Rind (D-WMR): An Overview of Nonlinear and Linear Regression and Error Analysis.

Sustainable wastewater treatment is one of the biggest issues of the 21st century. Metals such as Zn2+ have been released into the environment due to rapid industrial development. In this study, dried watermelon rind (D-WMR) is used as a low-cost adsorption material to assess natural adsorbents' ability to remove Zn2+ from synthetic wastewater. D-WMR was characterized using scanning electron microscope (SEM) and X-ray fluorescence (XRF). According to the results of the analysis, the D-WMR has two colours, white and black, and a significant concentration of mesoporous silica (83.70%). Moreover, after three hours of contact time in a synthetic solution with 400 mg/L Zn2+ concentration at pH 8 and 30 to 40 °C, the highest adsorption capacity of Zn2+ onto 1.5 g D-WMR adsorbent dose with 150 µm particle size was 25 mg/g. The experimental equilibrium data of Zn2+ onto D-WMR was utilized to compare nonlinear and linear isotherm and kinetics models for parameter determination. The best models for fitting equilibrium data were nonlinear Langmuir and pseudo-second models with lower error functions. Consequently, the potential use of D-WMR as a natural adsorbent for Zn2+ removal was highlighted, and error analysis indicated that nonlinear models best explain the adsorption data.

Production of Zinc and Copper as Nanoparticles by Green Synthesis Using Pseudomonas fluorescens.

<b>Background and Objective:</b> Nanoparticles with a little size to an enormous surface (1-100 nm) have expected clinical, mechanical and agricultural applications. This study aimed to produce nano Zinc Oxide (ZnO) and nano Copper Oxide (CuO) particles by green synthesis. <b>Materials and Methods:</b> Two strains of <i>Pseudomonas fluorescens</i> i.e., PSI and PSII, both cell culture supernatants and cell pellets from the two strains were examined separately in CuSO₄ or ZnSO₄ solutions. The supernatants from both strains produced color changes in both solutions referring to the formation of nano CuO or ZnO particles. The solutions were examined for nano-particle characteristics using UV-spectroscopy, particle size and morphology were tested using a scanning electron microscope and transmission electron microscopy. <b>Results:</b> UV-Vis absorption spectrum of solutions at a wavelength range 200-800 nm exhibits a distinct absorption peak in the region of 238-331 and at 303-366 nm for CuO or ZnO NPs, respectively. Absorption bands and the characteristic Surface Plasmon Resonance (SPR) spectra confirm the existence of CuO and ZnO NPs. SEM analysis micrographs indicated that CuO NPs were formed as spherical particles, while the exact shape of ZnO NPs could be identified as oval aggregates. <b>Conclusion:</b> Changes of color occurred in both solutions of two strains referring to the formation of nano CuO or ZnO particles.

Zinc ionophores isolated from Terminalia bellirica fruit rind extract protect against cardiomyocyte hypoxia/reoxygenation injury.

The study aimed to isolate and characterize zinc ionophores from Terminalia bellirica fruit using a liposome assay and test its utility in H9c2 rat cardiomyoblasts cells subjected to hypoxia/reoxygenation. Ethyl acetate extract that exhibited zinc ionophore activity was resolved to yield three polyphenols that were characterized as epicatechin-3-gallate (ECG), epigallocatechin-3-gallate (EGCG) and epigallocatechin (EGC) by nuclear magnetic resonance and electrospray ionization-mass spectra. The polyphenols enhanced the uptake of zinc into the liposomes and increased FluoZin-3 fluorescence. These polyphenols in the presence of 10 µM ZnCl2 enhanced the zinc import into H9c2 cells, whose intracellular zinc levels were otherwise lowered upon hypoxia/reoxygenation. EGCG proved to be more potent than ECG, which indeed was more effective than EGC in improving cellular zinc levels and in attenuating the apoptosis of H9c2 cells after hypoxia/reoxygenation injury. The polyphenols required zinc for anti-apoptotic effect. The cardioprotective effect is indeed due to enhanced zinc uptake mediated by these polyphenols.

Fractionation of Heavy Metals in Multi-Contaminated Soil Treated with Biochar Using the Sequential Extraction Procedure.

Heavy metals (HMs) toxicity represents a global problem depending on the soil environment's geochemical forms. Biochar addition safely reduces HMs mobile forms, thus, reducing their toxicity to plants. While several studies have shown that biochar could significantly stabilize HMs in contaminated soils, the study of the relationship of soil properties to potential mechanisms still needs further clarification; hence the importance of assessing a naturally contaminated soil amended, in this case with Paulownia biochar (PB) and Bamboo biochar (BB) to fractionate Pb, Cd, Zn, and Cu using short sequential fractionation plans. The relationship of soil pH and organic matter and its effect on the redistribution of these metals were estimated. The results indicated that the acid-soluble metals decreased while the fraction bound to organic matter increased compared to untreated pots. The increase in the organic matter metal-bound was mostly at the expense of the decrease in the acid extractable and Fe/Mn bound ones. The highest application of PB increased the organically bound fraction of Pb, Cd, Zn, and Cu (62, 61, 34, and 61%, respectively), while the BB increased them (61, 49, 42, and 22%, respectively) over the control. Meanwhile, Fe/Mn oxides bound represents the large portion associated with zinc and copper. Concerning soil organic matter (SOM) and soil pH, as potential tools to reduce the risk of the target metals, a significant positive correlation was observed with acid-soluble extractable metal, while a negative correlation was obtained with organic matter-bound metal. The principal component analysis (PCA) shows that the total variance represents 89.7% for the TCPL-extractable and HMs forms and their relation to pH and SOM, which confirms the positive effect of the pH and SOM under PB and BB treatments on reducing the risk of the studied metals. The mobility and bioavailability of these metals and their geochemical forms widely varied according to pH, soil organic matter, biochar types, and application rates. As an environmentally friendly and economical material, biochar emphasizes its importance as a tool that makes the soil more suitable for safe cultivation in the short term and its long-term sustainability. This study proves that it reduces the mobility of HMs, their environmental risks and contributes to food safety. It also confirms that performing more controlled experiments, such as a pot, is a disciplined and effective way to assess the suitability of different types of biochar as soil modifications to restore HMs contaminated soil via controlling the mobilization of these minerals.

Speciation of Zn and Cu in Technosol and evaluation of a sequential extraction procedure using XAS, XRD and SEM-EDX analyses.

Metal speciation, linked directly to bioaccessibility and lability, is a key to be considered when assessing associated human and environmental health risks originated from anthropogenic activities. To identify the Zn and Cu speciation in the highly contaminated, technogenically transformed soils (Technosol) from the impact zone near the industrial sludge reservoirs of chemical plant (Siverskyi Donets River floodplain, southern Russia), the validity of the BCR sequential extraction procedure using the X-ray absorption fine-structure and X-ray powder diffraction (XRD) analyses was examined after each of the three stages. After the removal of exchange and carbonate-bonded Zn and Cu compounds from Technosol (first stage of extraction), the resulting residual soil showed enrichment in a great diversity of metal compounds, primarily with Me-S and Me-O bonds. The number of compounds with a higher solubility decreased at the subsequent stages of extraction. In the residual soil left over after extracting the first and second fractions, the dominant Zn-S bond appeared as würtzite (hexagonal ZnS) that made up more than 50%, while the Cu-S bond was almost completely represented only by chalcocite (Cu2S). The XRD analysis revealed the authigenic minerals of metals with S: sphalerite (cubic ZnS), würtzite (hexagonal ZnS), covellite (CuS) and bornite (Cu5FeS4). The scanning electron microscopy data confirmed that würtzite was the dominant form of Me with sulfur-containing and carbonate-containing minerals. The Zn-S bond was the main component (57%), whereas the Cu-O bond was dominant in the residual fraction (the fraction after the third-stage extraction). The results revealed that the composition of the residual fractions might include some of the most stable and hard-to-recover metal compounds of technogenic origin. Thus, the application of the novel instrumental methods, coupled with the chemical fractionation, revealed the incomplete selectivity of the extractants in the extraction of Zn and Cu in long-term highly contaminated soils.

Tools and techniques for illuminating the cell biology of zinc.

Zinc (Zn2+) is an essential micronutrient that is required for a wide variety of cellular processes. Tools and methods have been instrumental in revealing the myriad roles of Zn2+ in cells. This review highlights recent developments fluorescent sensors to measure the labile Zn2+ pool, chelators to manipulate Zn2+ availability, and fluorescent tools and proteomics approaches for monitoring Zn2+-binding proteins in cells. Finally, we close with some highlights on the role of Zn2+ in regulating cell function and in cell signaling.

Phyto-Facilitated Bimetallic ZnFe2O4 Nanoparticles via Boswellia carteri: Synthesis, Characterization, and Anti-Cancer Activity.

BACKGROUND: The growing dissatisfaction with the available traditional chemotherapeutic agents has enhanced the need to develop new methods for obtaining materials with more effective and safe anti-cancer properties. Over the past few years, the usage of metallic nanoparticles has been a target for researchers of different scientific and commercial fields due to their tiny sizes, environment-friendly properties, and a wide range of applications. To overcome the obstacles of traditional physical and chemical methods for the synthesis of such nanoparticles, a new, less expensive, and eco-friendly method has been adopted using natural existing organisms as a reducing agent to mediate the synthesis of the desired metallic nanoparticles from their precursors, a process called green biosynthesis of nanoparticles. OBJECTIVE: In the present study, zinc-iron bimetallic nanoparticles (ZnFe2O4) were synthesized via an aqueous extract of Boswellia carteri resin mixed with zinc acetate and iron chloride precursors, and they were tested for their anticancer activity. METHODS: Various analytic methods were applied for the characterization of the phyto synthesized ZnFe2O4, and they were tested for their anticancer activity against MDA-MB-231, K562, MCF-7 cancer cell lines, and normal fibroblasts. RESULTS: Our results demonstrate the synthesis of cubic structured bimetallic nanoparticles ZnFe2O4 with an average diameter of 10.54 nm. MTT cytotoxicity assay demonstrates that our phyto-synthesized ZnFe2O4 nanoparticles exhibited a selective and potent anticancer activity against K562 and MDA-MB-231 cell lines with IC50 values 4.53 µM and 4.19 µM, respectively. CONCLUSION: In conclusion, our biosynthesized ZnFe2O4 nanoparticles show a promising, environmentally friendly, and low coast chemotherapeutic approach against selective cancers with a predicted low adverse side effect toward normal cells. Further, in vivo, advanced animal research should be done to execute their applicability in living organisms.

Metallomics Analysis for Assessment of Toxic Metal Burdens in Infants/Children and Their Mothers: Early Assessment and Intervention Are Essential.

Accumulation of toxic metals in infants/children is of serious concern worldwide, from the viewpoint of their harmful effects on the normal growth and development. This metallomics study investigates the extent of toxic metal burdens in infants/children and the relationship to those in their mothers for 77 child/mother pair subjects. For mercury, its geometric mean concentration in infants/children was of similar level to that in their mothers, and a high-significant close correlation was observed between infants/children and their mothers (ß = 0.758, r = 0.539, p < 0.0001). A significant but less intimate mother/child relationship was observed for arsenic (ß = 0.301, r = 0.433), lead (ß = 0.444, r = 0.471) and aluminum (ß = 0.379, r = 0.451). Remarkably, the burden levels of lead, cadmium and aluminum in infants/children were approximately three times higher than those in their mothers (p < 0.0001), and the burden levels in some individuals were several tens of times higher than in the mothers. In contrast, some essential metal levels such as zinc, magnesium and calcium in infants/children were significantly lower than those in their mothers, and 29 individuals (37.7%) in the child subjects were estimated to be zinc-deficient. In addition, significant inverse correlations were observed between zinc and lead (r = -0.267, p = 0.019), and magnesium and arsenic (r = -0.514, p < 0.0001). These findings suggest that these toxic metal burdens and essential metal deficiencies in infants/children are of serious concern for their neurodevelopment, indicating that the early assessment and intervention are crucial. It is expected that larger epidemiological and intervention studies will provide a reasonable and essential pathway for intervention of neurodevelopment disorders.

Poly(styrene)-co-2-vinylpyridine copolymer as a novel solid-phase adsorbent for determination of manganese and zinc in foods and vegetables by FAAS.

The aim of this study is to extract zinc and manganese from foods and vegetables using an amphiphilic copolymer adsorbent, poly(styrene)-co-2-vinylpyridine which was synthesized via reversible addition fragmentation chain transfer (RAFT) polymerization from styrene and 2-vinyl pyridine in the presence of a trithiocarbonate and 2,2'-azo-bis isobutyro nitrile (AIBN) in toluene solution under argon at 80 °C. Fourier Transform Infrared (FTIR) and proton nuclear magnetic resonance (1H NMR) spectroscopy were used in the characterization of the obtained copolymer. Under the optimum conditions, several validation variables such as uncertainty measurement, selectivity, robustness, precisions, matrix effects and accuracy were investigated. Taking an adsorption time of 15 min, detection limits of 0.04 µg L -1 and 0.2 µg L-1and 7.9 µg L-1and enrichment factors of 145 and 110 were obtained for Mn(II) and Zn(II), respectively.The method was successfully applied to the analysis of Mn(II) and Zn(II) in foods and vegetables.

A Comparative Study on Cu2+, Zn2+, Ni2+, Fe3+, and Cr3+ Metal Ions Removal from Industrial Wastewaters by Chitosan-Based Composite Cryogels.

Materials coming from renewable resources have drawn recently an increased attention in various applications as an eco-friendly alternative in the synthesis of novel functional materials. Polysaccharides, with their prominent representative - chitosan (CS), are well-known for their sorption properties, being able to remove metal ions from dilute solutions either by electrostatic interactions or chelation. In this context, we proposed here a comparative study on Cu2+, Zn2+, Ni2+, Fe3+, and Cr3+ metal ions removal from industrial wastewaters by CS-based composite cryogels using batch technique. The composite cryogels consisting of CS embedding a natural zeolite, namely clinoptilolite, were synthesized by cryogelation, and their sorption performance were compared to those of CS cryogels and of acid-activated zeolite. A deeper analysis of thermodynamics and kinetics sorption data was performed to get insights into the sorption mechanism of all metal ions onto sorbents. Based on the optimized sorption conditions, the removal of the above-mentioned ions from aqueous solutions by the composite sorbent using dynamic technique was also evaluated.

Efficient separation of Zn(â ¡) from Cd(â ¡) in sulfate solution by mechanochemically activated serpentine.

Clay minerals are widely used to treat sewage containing heavy metals such as zinc and cadmium. In this study, the chemical reactivity of natural serpentine was signally improved through mechanochemical activation, achieving the efficient separation of Zn(Ⅱ) and Cd(Ⅱ) ions in a mixed solution. The activated serpentine would release a large amount of Mg2+ and OH- and thereby selectively precipitate Zn(Ⅱ) ions as an uncommon metamorphic zinc mineral, bechererite, in the presence of SO42-. By adjusting the parameters including grinding intensity, reaction temperature, serpentine dosage and salt species, the optimum conditions were determined and a 92% separation rate of Zn(Ⅱ) and Cd(Ⅱ) ions was achieved. The mechanochemical activation of natural clay minerals expresses a great potential for purification of heavy metal contaminated sewage, as well as the simultaneous separation and recovery of multi-metal secondary resources.

Total metal content and chemical speciation analysis of iron, copper, zinc and iodine in human breast milk using high-performance liquid chromatography separation and inductively coupled plasma mass spectrometry detection.

The aim of this research was to quantify essential trace elements (iron, copper, zinc and iodine) and establish their speciation in human milk. Both the element and the species are important in new-born nutrition. Colostrum, and transitional and mature milks (25) were collected from 18 mothers of pre-term or full-term infants. Concentrations of the target elements were determined using ICP-MS. For speciation, HPLC coupled to ICP-MS was employed. Total contents of the micronutrients varied in mothers of pre-term (Fe = 0.997, Cu = 0.506, Zn = 4.15 and I = 0.458 mg L-1) and mothers of full-term (Fe = 0.733, Cu = 0.234, Zn = 2.91 and I = 0.255 mg L-1) infants. Fe, Cu and Zn were associated with biomolecules with high molecular mass compounds, such as immunoglobulins, albumin and lactoferrin whilst iodine was only found as iodide.

Purification Behavior of Zn(II) in Water by Magnesium Hydroxyapatite: Surface Complexation, and Dissolution-Precipitation.

As an innovative and economical material, hydroxyapatite does little harm to the environment. In this study, a magnesium hydroxyapatite (Mg-HAP) adsorbent was prepared by doping magnesium. Magnesium doping can increase the hydroxyl groups on the surface of Mg-HAP to form more adsorption sites and improve the removal effect of the heavy metal Zn(II) in water. This study was implemented to survey the effect of different sorption elements, including the liquor initial pH, initial concentration, dose of adsorbents, and other factors, on the adsorption effect. The outcomes show that the sorption effect was best at the time that the liquor was weakly acidic (pH = 6); At a pH of 6, the temperature of 25 °C when the optimal dosage of adsorbent is 0.25 g, the maximum adsorption amount is 62.11 mg/g. Through data fitting, the adsorption process can be accurately described as a pseudo-second-order dynamics model and the Langmuir isotherm equation. According to the thermodynamic analysis, the sorption of zinc ions by Mg-HAP belongs to the process of spontaneous endothermic and entropy increase, and the increase of temperature was conducive to adsorption. Material characterization and analysis indicate that surface complexation and dissolution-precipitation was the main mechanism for adsorption of Zn(II).

A review on the applicability of activated carbon derived from plant biomass in adsorption of chromium, copper, and zinc from industrial wastewater.

Metal ion contamination in wastewater is an issue of global concern. The conventional methods of heavy metal removal from wastewater have some drawbacks, ranging from generation of sludge to high cost of removal. Adsorption technique for copper(II), zinc(II), and chromium(VI) using activated carbon has been found efficient. However, it is not economical on a large scale. This, therefore, necessitates the search for economical and readily available plant biomass-based activated carbons for the sequestration of the metal ions. This review presents the state of the art on the adsorption of copper(II), zinc(II), and chromium(VI) from industrial wastewater. Based on the literature review presented, the groundnut husk and corncob based activated carbons were found to possess the maximum adsorption capacities for copper(II), zinc(II), and chromium(VI) removal, when compared with the other plant biomass-based activated carbons. The high values of the adsorption capacities obtained were as a result of the isotherms and pH of the adsorbent as well as the initial concentration of the metal solutions. From the review, the equilibrium data fitted better with Langmuir and Freundlich isotherms than with other isotherms. Research gaps were identified which include a need to investigate the kinetic and the thermodynamic behaviors of the metal ions onto the studied adsorbents. Furthermore, a comparative analysis of the three types of activation of the adsorbents should be investigated using single and multi-metals. The optimization of particle size, contact time, temperature, initial concentration, and adsorbent dosage for adsorption of copper(II), zinc(II), and chromium(VI) onto the studied adsorbents using response surface methodology is equally required.

Removal of Zinc from Aqueous Solutions Using Lamellar Double Hydroxide Materials Impregnated with Cyanex 272: Characterization and Sorption Studies.

Removal of heavy metals from wastewater is mandatory in order to avoid water pollution of natural reservoirs. In the present study, layered double hydroxide (LDH) materials were evaluated for removal of zinc from aqueous solutions. Materials thus prepared were impregnated with cyanex 272 using the dry method. These materials were characterized through X-ray diffraction (XRD), Fourier transform infrared (FTIR), and thermal analysis. Batch shaking adsorption experiments were performed in order to examine contact time and extraction capacity in the removal process. Results showed that the equilibrium time of Zn (II) extraction is about 4 h for Mg2Al-CO3 and Mg2Al-CO3-cyanex 272, 6 h for Zn2Al-CO3, and 24 h for Zn2Al-CO3-cyanex 272. The experimental equilibrium data were tested for Langmuir, and Freundlich isotherm models. Correlation coefficients indicate that experimental results are in a good agreement with Langmuir's model for zinc ions. Pseudo-first, second-order, Elovich, and intraparticular kinetic models were used to describe kinetic data. It was determined that removal of Zn2+ was well-fitted by a second-order reaction kinetic. A maximum capacity of 280 mg/g was obtained by Zn2Al-CO3-cyanex 272.

Extracting bio-zinc and taurine from Pinctada martensii meat.

Recently, intensive processing of marine resources has attracted considerable attention. In order to further utilize the byproducts of aquatic shellfish (Pinctada martensii meat) with high value, this study proposes a method of extracting zinc and taurine from P. martensii meat. Zinc was first extracted from P. martensii meat with an ultrasonic crusher, and then taurine was further extracted by ultrasonic-assisted water extraction from the remaining shellfish. After optimization, the biological zinc extraction rate reached 8.63%, and the taurine extraction rate reached 0.71%. Meanwhile, the parameters for cation exchange separation and taurine purification were optimized, in which the injection volume, pH value, and elution rate were set to 8.0 mL, 4.5, and 3.0 mL/min, respectively. Ultimately, the purity the extracted taurine reached 98.16%. This study provides a novel method for the extraction of biological zinc and taurine by deep processing of shellfish meat.

Emerging applications of biochar: Improving pig manure composting and attenuation of heavy metal mobility in mature compost.

This study evaluated the effect of integrated bacterial culture and biochar on heavy metal (HM) stabilization and microbial activity during pig manure composting. High-throughput sequencing was carried out on six treatments, namely T1-T6, where T2 was single application of bacteria culture (C), T3 and T5 were supplemented with 12 % wood (WB) and wheat-straw biochar (WSB), respectively, and T4 and T6 had a combination of bacterial consortium mixed with biochar (12 % WB and 12 % WSB, respectively). T1 was used as control for the comparison. The results show that the populations of bacterial phyla were significantly greater in T6 and T4. The predominate phylum were Proteobacteria (56.22 %), Bacteroidetes (35.40 %), and Firmicutes (8.38 %), and the dominant genera were Marinimicrobium (53.14 %), Moheibacter (35.22 %), and Erysipelothrix (5.02 %). Additionally, the correlation analysis revealed the significance of T6, as the interaction of biochar and bacterial culture influenced the HM adsorption efficiency and microbial dynamics during composting. Overall, the integrated bacterial culture and biochar application promoted the immobilization of HMs (Cu and Zn) owing to improved adsorption, and enhanced the abundance and selectivity of the bacterial community to promote degradation and improving the safety and quality of the final compost product.