Search

Thiabendazole (TBZ), a recalcitrant fungicide, is frequently applied in postharvest fruit treatment and generates significant volumes of industrial wastewater (WW) that conventional treatment plants cannot handle. This explores a bioelectrochemical system (BES) for TBZ degradation using Tunisian hypersaline sediments (THSs) as inoculum. Four sets of BES, along with biological controls, were tested using THS subjected to different levels of TBZ biostimulation. Sediments underwent one, two, or three biostimulation phases with increasing TBZ concentrations (0, 10, 100, and 300 mg kg−1). Potentiostatic control was applied to BES, polarized at 0.1 V vs. saturated calomel reference electrode (SCE), with a carbon felt working electrode (72 cm2 L−1) and maintained at 25°C. While current production was very low, sediments biostimulated with 100 mg kg−1 kg TBZ produced the highest current density (3.2 mA m−2), a 5-fold increase over untreated sediments (0.6 mA m−2). GC-FID analysis showed >99% TBZ degradation in all reactors. The TBZ half-elimination time from 27 days with biological treatments to 19 days in BES and further to 6 days following biostimulation. Bacterial analysis revealed a substantial microbial community shift after biostimulation, with a reduction in Bacillota (−64%) and an increase in Proteobacteria (+62%), dominated by Pseudomonas (45%) and Marinobacter (16%). These findings provide insight into the selective potential of biostimulation cycles to enhance microbial community composition and improve BES performance for TBZ wastewater treatment. [ABSTRACT FROM AUTHOR]

Antibiotics are extensively used to manage human, animal and plant ailments caused by microbial infections. However, rampant use of antibiotics has led to the development of antibiotic resistance, which is a public health concern. The development of antibiotic resistance is significantly influenced by agro-ecosystems. Rice agroecosystem receives high levels of antibiotics from direct applications, and sources like manure and irrigation water. Consequently, uptake of antibiotic residues by rice (Oryza sativa L.) is resulting in accumulation of antibiotics in plant parts. Accumulation of these antibiotics can be toxic to plant, and can be partitioned to rice grain and straw, and reach the human and animal food chain leading to the development of antibiotic resistance. Moreover, the antibiotics can alter soil microbes, which would result in loss of production. This study compiles information from existing literature on global antibiotic usage and explores how antibiotics enter the rice ecosystem through contaminated wastewater, manure, sewage sludge, and through direct application. A detailed discussion on the persistence and movement of antibiotics in different environment compartments is provided. The review also highlights the impacts of antibiotics on plants and natural microbiota, as well as issues pertaining to antimicrobial resistance in public health sectors. For sustainable mitigation of the issues of antibiotic residues in rice ecosystem, we suggest application of decontaminated manure, microbial bioremediation, optimization of the use of plant-based alternatives, enhancing regulations, and fostering global collaboration. We advocate integrated disease management approaches which can significantly reduce the antibiotic use in rice agroecosystem. [ABSTRACT FROM AUTHOR]

Bioremediation induced by bacteria offers a promising alternative for the contamination of aromatic hydrocarbons due to their metabolic processes suitable for the removal of these pollutants, as many of them are carcinogenic molecules and dangerous to human health. Our research focused on isolating a bacterium from the rhizosphere of the tara tree with the ability to degrade polycyclic aromatic hydrocarbons, using draft genomic sequencing and computational analysis. Enterobacter sp. strain UNJFSC 003 possesses 4460 protein-coding genes, two rRNA genes, 77 tRNA genes, and a GC content of 54.38%. A taxonomic analysis of our strain revealed that it has an average nucleotide identity (ANI) of 87.8%, indicating that it is a new native Enterobacteria. Additionally, a pangenomic analysis with 15 strains demonstrated that our strain has a phylogenetic relationship with strain FDAARGOS 1428 (Enterobacter cancerogenus), with a total of 381 core genes and 4778 accessory genes. Orthologous methods predicted that strain UNJFSC 003 possesses genes with potential for use in hydrocarbon bioremediation. Genes were predicted in the sub-pathways for the degradation of homoprotocatechuate and phenylacetate, primarily located in the cytoplasm. Studies conducted through molecular modeling and docking revealed the affinity of the predicted proteins in the degradation of benzo[a]pyrene in the homoprotocatechuate sub-pathway, specifically hpcB, which has enzymatic activity as a dioxygenase, and hpcC, which functions as an aldehyde dehydrogenase. This study provides information on native strains from Lomas de Lachay with capabilities for the bioremediation of aromatic hydrocarbons and other compounds. [ABSTRACT FROM AUTHOR]

• S. alfredii may be a phytoremediation material for HCMHMs soil. • Heavy metals migrated to rhizosphere soil and were mainly concentrated in roots and leaves by S. alfredii. • Bacteria increased the abundance of some quorum sensing signaling molecules under HCMHMs stress. • Bacteria promoted the path expression that converts serine to cysteine under HCMHMs stress. Pollution accident of nonferrous metallurgy industry often lead to serious heavy metal pollution of the surrounding soil. Phytoremediation of contaminated soil is an environmental and sustainable technology, and soil native microorganisms in the process of phytoremediation also participate in the remediation of heavy metals. However, the effects of high concentrations of multiple heavy metals (HCMHMs) on plants and native soil microorganisms remain uncertain. Thus, further clarification of the mechanism of phytoremediation of HCMHMs soil by plants and native soil microorganisms is required. Using the plant Sedum alfredii (S. alfredii) to restore HCMHM-contaminated soil, we further explored the mechanism of S. alfredii and native soil microorganisms in the remediation of HCMHM soils. The results showed that (i) S. alfredii can promote heavy metals from non-rhizosphere soil to rhizosphere soil, which is conducive to the effect of plants on heavy metals. In addition, it can also enrich the absorbed heavy metals in its roots and leaves; (ii) native soil bacteria can increase the abundance of signal molecule-synthesizing enzymes, such as trpE, trpG, bjaI, rpfF, ACSL , and yidC , and promote the expression of the pathway that converts serine to cysteine, then synthesize substances to chelate heavy metals. In addition, we speculated that genes such as K19703, K07891, K09711, K19703, K07891, and K09711 in native bacteria may be involved in the stabilization or absorption of heavy metals. The results provide scientific basis for S. alfredii to remediate heavy metals contaminated soils, and confirm the potential of phytoremediation of HCMHM contaminated soil. [ABSTRACT FROM AUTHOR]

Sludge biochar, as a soil amendment, has demonstrated its capacity to remediate heavy metal-contaminated soil. It is frequently utilized to facilitate phytoremediation or as a microbial carrier in remediation strategies, aiming to enhance overall remediation efficiency. Nonetheless, there exists a knowledge gap regarding the influence of biochar on the migration and accumulation of Pb and Zn within soil-microbe-plant systems, as well as its effects on plant growth conditions and microbial community composition. This study constructed a multifunctional microbiome and evaluated the role of microbiome and biochar in phytoremediation under Pb and Zn stress. Biochar immobilized microbiome (MB) significantly enhanced phytoremediation and showed synergistic effects by improving root phenotypes up to 2.4 times compared to the untreated group (CK). Meanwhile, the MB increased Pb root absorption by 56.9% and Zn aboveground transfer by 30%, and reduced the acid-extractable content of Pb and Zn under high concentrations. In addition, microbial community composition and diversity analyses showed that the bacterial and fungal communities of MB were more stable while multifunctional microbiome reshaped microbial community with boosted abundance of plant growth promoting microorganisms, and fungi of saprotroph and symbiotroph nutritional categories. This study provided a novel phytoremediation approach of castor with the combination of multifunctional microbiome and biochar. Highlights: Castor effectively transfers Zn to aboveground parts (TFmax = 2.89). Natural slag was detrimental to root growth, with 60.6% decrease in phenotypes. MB synergistically enhanced root length, surface area, tip, and volume to 2.4 times. MB increased Pb root absorption by 56.9% and Zn above-ground transfer by 30%. Multifunctional microbiome boosted the abundance of PGPRs. [ABSTRACT FROM AUTHOR]

Petroleum-contaminated soils provide an ideal environment for hydrocarbon-degrading bacteria, necessitating the study of their microbial ecology and community changes. This research compared diesel-impacted power plant soil (PPS) from the University of Calabar with pristine soil (CSS) as a control, the samples (50 g) were randomly collected from depths of 0–15 cm, 15–30 cm, and 30–45 cm. Physicochemical and metagenomic analyses were conducted. Taxonomic profiling with functional gene analyses via COG and PRK frameworks performed. PPS displayed higher concentrations of organic carbon (7.02%), total petroleum hydrocarbons (8500 mg/kg), nitrogen (0.51%), phosphorus (3.65 g/kg), lead (175 mg/kg), iron (2619 mg/kg), and copper (196.55 mg/kg) than CSS. Conversely, CSS had higher pH, temperature, conductivity, and moisture content. Bacterial abundance was slightly higher in CSS (89.24%) than in PPS (87.47%), with distinct dominant microbial taxa between samples. Functional analysis identified COG Class I (lipid transport and metabolism) as the most abundant in PPS (32.37%), linked to the predominant hydrocarbon-degrading bacterium Bacillus amyloliquefaciens (26.24%), absent in CSS. In contrast, CSS had COG Class O (posttranslational modification) as the highest (94%). These results demonstrate that petroleum pollution promotes the growth of hydrocarbon-degrading bacteria, underscoring the ecological impacts of contamination on soil microbial communities. [ABSTRACT FROM AUTHOR]

Although bioremediation is considered the most environmentally friendly and sustainable technique for remediating contaminated soil and water, it is most effective when combined with physicochemical methods, which allow for the preliminary removal of large quantities of pollutants. This allows microorganisms to efficiently eliminate the remaining contaminants. In addition to requiring the necessary genes and degradation pathways for specific substrates, as well as tolerance to adverse environmental conditions, microorganisms may perform below expectations. One typical reason for this is the high toxicity of xenobiotics present in large concentrations, stemming from the vulnerability of bacteria introduced to a contaminated site. This is especially true for planktonic bacteria, whereas bacteria within biofilms or microcolonies have significant advantages over their planktonic counterparts. A physical matrix is essential for the formation, maintenance, and survival of bacterial biofilms. By providing such a matrix for bacterial immobilization, the formation of biofilms can be facilitated and accelerated. Therefore, bioremediation combined with bacterial immobilization offers a comprehensive solution for environmental cleanup by harnessing the specialized metabolic activities of microorganisms while ensuring their retention and efficacy at target sites. In many cases, such bioremediation can also eliminate the need for physicochemical methods that are otherwise required to initially reduce contaminant concentrations. Then, it will be possible to use microorganisms for the remediation of higher concentrations of xenobiotics, significantly reducing costs while maintaining a rapid rate of remediation processes. This review explores the benefits of bacterial immobilization, highlighting materials and processes for developing an optimal immobilization matrix. It focuses on the following four key areas: (i) the types of organic pollutants impacting environmental and human health, (ii) the bacterial strains used in bioremediation processes, (iii) the types and benefits of immobilization, and (iv) the immobilization of bacterial cells on various carriers for targeted pollutant degradation. [ABSTRACT FROM AUTHOR]

Bioremediation is widely recognized as a promising and efficient approach for the elimination of Cd from contaminated paddy soils. However, the Cd removal efficacy achieved through this method remains unsatisfactory and is accompanied by a marginally higher cost. Cysteine has the potential to improve the bioleaching efficiency of Cd from soils and decrease the use cost since it is green, acidic and has a high Cd affinity. In this study, different combination modes of cysteine and microbial inoculant were designed to analyze their effects on Cd removal and the soil microbial community through the sequence extraction of Cd fraction and high-throughput sequencing. The results demonstrate that the mixture of cysteine and the microbial inoculant was the best mode for increasing the Cd removal efficiency. And a ratio of cysteine to microbial inoculant of 5 mg:2 mL in a 300 mL volume was the most economically efficient matching. The Cd removal rate increased by 7.7–15.1% in comparison with the microbial inoculant treatment. This could be ascribed to the enhanced removal rate of the exchangeable and carbonate-bound Cd, which achieved 94.6% and 96.1%, respectively. After the treatment, the contents of ammonium nitrogen (NH3–N), total phosphorus (TP), available potassium (AK), and available phosphorus (AP) in the paddy soils were increased. The treatment of combinations of cysteine and microbial inoculant had an impact on the soil microbial diversity. The relative abundances of Alicyclobacillus, Metallibacterium, and Bacillus were increased in the paddy soils. The microbial metabolic functions, such as replication and repair and amino acid metabolism, were also increased after treatment, which benefitted the microbial survival and adaptation to the environment. The removal of Cd was attributed to the solubilizing, complexing, and ion-exchanging effects of the cysteine, the intra- and extracellular adsorption, and the production of organic acids of functional microorganisms. Moreover, cysteine, as a carbon, nitrogen, and sulfur source, promoted the growth and metabolism of microorganisms to achieve the effect of the synergistic promotion of microbial Cd removal. Therefore, this study underscored the potential of cysteine to enhance the bioremediation performance in Cd-contaminated paddy soils, offering valuable theoretical and technical insights for this field. [ABSTRACT FROM AUTHOR]

Contamination by heavy metals (HMs) poses a significant threat to the ecosystem and its associated micro and macroorganisms, leading to ill effects on humans which necessitate the requirement of effective remediation strategies. Microbial remediation leverages the natural metabolic abilities of microbes to overcome heavy metal pollution effectively. Some of the mechanisms that aids in the removal of heavy metals includes bioaccumulation, biosorption, and biomineralization. Metals such as Cd, Pb, As, Hg, and Cr are passively adsorbed by energy independent process onto the surface by exopolysaccharide sequestration or utilizing energy to transfer metals into the cell and interact with the biomolecules to be sequestered, or being converted into its various valencies, thereby reducing the toxicity. Application of hyperaccumulators has shown to be effective in the removal of HMs especially while augmented with microbes to the rhizosphere region. Omics studies which include metabolomics and metagenomics provide significant information about the microbial diversities and metabolic processes involved in heavy metal remediation, allowing the development of more reliable and sustainable bioremediation approaches. This review also summarizes the recent advancements in microbial remediation, including genetic engineering and nanotechnology that has revolutionized and offered an unprecedented control and precision in the removal of HMs. These innovations hold a promising stand for enhancing remediation efficiency, scalability, and cost-effectiveness. [ABSTRACT FROM AUTHOR]

Marine pollution from anthropogenic activities poses a severe threat to aquatic environments globally. Contaminants such as microplastics, hydrocarbons, heavy metals, and pesticides pervade coastal and ocean waters, causing significant harm to marine life and ecosystems. To address this, biological approaches present sustainable remediation alternatives. This review systematically evaluates recent advancements in bioaugmentation strategies for mitigating marine pollution. We begin by discussing key pollutant types, their sources, and their impacts. The review then explores various biological techniques, including microbial degradation, plant-assisted methods, and nano-enabled approaches. Significant advancements in predictive modeling, genetic engineering, and 'omics tools are also examined. Our comprehensive literature analysis (2010–2024) highlights progress in several areas: the optimization of tailored microbial consortia, development of pollution sensors, and integration of nanotechnologies. Notable achievements include the enhanced functional range and resilience of genetically engineered agents and the discovery of novel degraders through 'omics tools. Despite these advancements, challenges remain. Knowledge gaps exist regarding the interactions between diverse marine microbes, and scaling bioaugmentation to address complex pollutant mixtures poses ongoing difficulties. Addressing these challenges requires sustained efforts across scientific, policy, and social domains to fully realize the potential of bioaugmentation for ocean protection. Article Highlights: Highlights advanced bioaugmentation strategies as sustainable alternatives for addressing marine pollution from microplastics, hydrocarbons, heavy metals, and pesticides. Showcases significant progress in microbial consortia optimization, pollution sensors, and integration of nanotechnologies. Emphasizes the impact of predictive modeling, genetic engineering, and 'omics tools in enhancing bioaugmentation effectiveness. Identifies ongoing challenges and knowledge gaps in microbial interactions and scaling techniques, underscoring the need for continued research and interdisciplinary efforts. [ABSTRACT FROM AUTHOR]

AbstractPyrethroids are synthetic products derived from natural pyrethroids present in flowers and are extensively used as pesticides for agriculture, animal husbandry, and household pest control. However, excessive and prolonged usage of pyrethroid insecticides can result in adverse effects on both non-target and target species. Therefore, effective technologies need to be developed to remove pyrethroid contamination and ensure environmental safety. Microbial remediation of various pesticide contaminants is highly practicable, low cost, and eco-friendly compared to physical and chemical methods. Different microbiota are screened to eliminate or degrade the contaminants. Microbial remediation technology utilizes the natural ability of microbiota to treat contaminated areas. Previous studies have mostly focused on the isolation and screening of microorganisms for pyrethroid biodegradation, as well as on the kinetics and pathways of pyrethroid biodegradation. In order to develop effective bioremediation strategies, further research based on molecular biology and bioengineering is required for a comprehensive exploration of pyrethroid-degrading microorganisms. To date, the microbial degradation of pyrethroid pesticides and the underlying mechanisms have been rarely reviewed. Therefore, this critical review encompasses the latest knowledge on synthetic pyrethroids from structural properties, bio-toxicity, and characterization of microbial degradation strains to degradation characteristics, intrinsic mechanisms, and microbial degradation pathways. The future of microbial remediation depends on combining advanced gene technology with traditional bioremediation methods to sustainably degrade pesticide contaminants. It also summarizes the factors affecting degradation efficiency and concludes with prospects, along with current challenges and limitations. [ABSTRACT FROM AUTHOR]

Background: 1,2-dichloroethane (1,2-DCA) biodegradation can occur through aerobic or anaerobic pathways that can be exploited in bioremediation strategies. Bioremediation interventions are site specific and generally based on anaerobic pathways, nevertheless expanding knowledge on proper conditions favoring the biodegradation and especially on 1,2-DCA degrading microorganisms is crucial. In this work the intrinsic biodegradation potential of an aquifer impacted by Chlorinated Aliphatic Hydrocarbons (mainly 1,2-DCA) was evaluated by characterizing the aquifer microbiome across space and time and by setting up biostimulation treatments in microcosms under different aerobic and anaerobic conditions, in parallel. Results: The microbial profiling of the aquifer revealed noticeable alpha and beta diversity across the sampling sites within the aquifer and strong fluctuations over time. Surprisingly both the anaerobic and aerobic biostimulation treatments led to the successful removal of 1,2-DCA in microcosms, the enrichment of known 1,2-DCA degraders and the detection of reductive or hydrolytic dehalogenases. Ancylobacter and Starkeya were enriched in aerobic microcosms. Desulfovibrio and Desulfuromonas, known as perchloroethylene degraders, were enriched in anaerobic microcosms, suggesting they could be yet unknown 1,2-DCA respirers. Conclusions: Our results demonstrate the occurrence of both aerobic and anaerobic bioremediation potential in the aquifer despite its negative redox potential. Due to the feasibility of direct oxidation with oxygen insufflation, we propose that an enhanced bioremediation strategy based on direct oxidation of 1,2-DCA could be applied to the contaminated aquifer as an ecofriendly, efficient and cost-effective approach as an alternative to anaerobic biodegradation. [ABSTRACT FROM AUTHOR]

Gold mine operations release toxic arsenic and other heavy metals into the environment, which can be accumulated in water resources and the food chain. As microbial bioremediation has been a promising method for pollutant removal from contaminated sites, the identification of bacterial communities in arsenic-contaminated resources has recently been in focus. The bacterial communities of tailings dam effluent (TDE) of a gold mine in Iran were analyzed. The bacterial communities were examined using the next-generation sequencing method (Illumina platform) targeting the V3-V4 region of 16S rRNA genes. The 16S rRNA dataset from this study was compared with three arsenic-contaminated groundwater (GW) microbiomes from SRA databases, using the bioinformatics tool QIIME 2. Our findings revealed that the prevalent taxonomic groups observed in all of the samples belonged to Proteobacteria (8.06-45.49%), Bacteroidetes (1.85-50.32%), Firmicutes (1.00-6.2%) and Actinobacteria (0.86-5.09%). Metagenomic analyses showed that Algoriphagus, Rhodobacter, Anaerospora, Limnobacter, Halomonas and Yonghaparkia are the main bacterial genera in TDE. Despite the limited similarities in the prokaryotic community of the samples, the most of the retrieved genera of the TDE are unique and the native bacteria of Iran.Conclusions: Long-term exposure to arsenic causes changes in bacterial abundance and richness. This resulted in natural selection and expression of the most compatible genes in existing condition. Although there are similarities in some microbial communities of ground waters, but it can be found some native microorganisms, which was adapted to the harsh environment of TDE. [ABSTRACT FROM AUTHOR]

In the present study, the relationship between the microbial community and heavy metal content of soil was analyzed based on 16S rRNA gene high-throughput sequencing, in order to screen the corresponding heavy metal-resistant bacteria in a copper mine waste dump and adjacent shrubbery. Approximately 22 phyla, 57 classes, 128 orders, 173 families, 263 genera, 433 species, and 954 OUTs obtained from soil sample species annotation indicated the Spearman relevance analysis at the phylum level. Specifically, Gemmatimonadota is positively correlated with arsenic (As); Patescibacteria is positively correlated with arsenic (As), copper (Cu), and cadmium (Cd); Proteobacteria is positively correlated with chromium (Cr); and Acidobacteriota is positively correlated with cadmium (Cd), respectively. Meanwhile, at the genus level, Acidibacter is positively correlated with arsenic (As); norank_f__LWQ8, norank_f__Gemmataceae, and Bryobacter are positively correlated with cadmium (Cd); Acidiphilium and Conexiactor are positively correlated with Zinc (Zn); norank_f__norank_o__IMCC26256 is positively correlated with nickel (Ni); norank_f__norank_o__norank_c__AD3 is positively correlated with manganese (Mn), and nickel (Ni); and Alicyclobacillus and unclassified_f__Acidiferobactereae are positively correlated with chromium (Cr). These bacterial flora are significantly and positively related to the resistance of heavy metals, which provides a promising reference for the development of in situ remediation of heavy metal pollution in mines. [ABSTRACT FROM AUTHOR]

Microbial electric syntrophy, involving direct electron transfer between electron-donating strains and electron-accepting strains, could reduce more than 50% of methane emissions and remove 90% of nitrate pollution in some wastewaters. Microbial electric syntrophy is also a key natural process allowing the survival of bacteria in harsh environmental conditions. Here we review natural and artificial cases of interspecies electron transfer in microbial syntrophy, with emphasis on methane production, electroactive bacteria, methanogens, anaerobic methane-oxidizing consortia, Geobacter species, phototrophic bacteria, co-cultures, anaerobic digestion, environmental remediation and microbial electrosynthesis. Environmental remediation includes nitrogen removal, reductive dechlorination and pollutant degradation. Microbial electrosynthesis can be used for carbon dioxide reduction. Conductive proteins and materials, and light-assisted electron transfer contribute to the direct interspecies electron transfer. [ABSTRACT FROM AUTHOR]

Soil contamination with petroleum hydrocarbons poses a significant environmental challenge, necessitating effective remediation strategies to mitigate ecological risks. This review paper systematically examines the current state of knowledge regarding soil contamination with petroleum hydrocarbons, focusing on diverse sources and the extent of contamination. The investigation encompasses a range of hydrocarbon compounds, including aliphatic and aromatic fractions, emphasizing the dynamic nature of the contamination scenarios. A thorough review of bioremediation techniques, which have shown promise and sustainability as methods for cleaning up soil contaminated with petroleum hydrocarbons are also involved in order to solve these issues. Each of the three microbial processes, biodegradation, bioaugmentation, and biostimulation, is covered in detail in the paper, along with the complex mechanics underlying each technique. The report also emphasises new developments in genetics and molecular biology that add to our understanding of the metabolic pathways and microbial interactions involved in hydrocarbon breakdown. The effectiveness of plantassisted bioremediation coupled with bioaugmentation and stimulation, specifically phytoremediation, is also explored, emphasizing the potential of certain plant species to enhance the removal of petroleum hydrocarbons from contaminated soils through rhizosphere interactions and plant-associated microbial activities. Furthermore, the paper evaluates the influence of environmental variables including soil composition, temperature, and moisture content on the effectiveness of bioremediation techniques, offering valuable perspectives on enhancing remediation efficiency through optimal conditions. The possibility for enhancing conventional bioremediation techniques through the incorporation of cuttingedge technology like nano-remediation is also explored. [ABSTRACT FROM AUTHOR]

One of the effective and safe methods of soil cleanup from oil pollution is bioremediation by introducing microorganisms or their metabolites. In this study, the effect of biosurfactants produced by Nocardiopsis sp. 3mo on the rate of bioremediation of oil-contaminated soils was assessed. Biosurfactants were introduced into soils contaminated with 2% oil at a concentration of 0.05 and 0.1%, and the degree of hydrocarbon degradation was estimated within 63 days. It was found that the studied biosurfactant belonged to the glycopeptide type. The aeration and irrigation of oil-contaminated soil (PSA) resulted in a 5% decrease in the number of hydrocarbons. The introduction of biosurfactants into oil-contaminated soil at a concentration of 0.5 (BS(0.5)) and 1 g kg−1 (BS(1)) resulted in a 29 and 35% decrease in the content of hydrocarbons, respectively. The state of the soil microbiome was assessed by its metabolic activity. Thus, the respiratory activity of microorganisms on the first day after contamination increases by 5–7 times, and urease activity by 3–4 times. The introduction of oil into the soil during the first day reduces the activity of dehydrogenase by 2.3–1.6 times. In the process of bioremediation, the indicators of microbial activity returned to values close to the original. Thus, it was established that the use of biosurfactants produced by Nocardiopsis sp. 3mo increases the ability of the native soil community to degrade hydrocarbons. [ABSTRACT FROM AUTHOR]

This study presents the results of evaluating hydrocarbonoclastic consortia in the biodegradation of microplastics derived from single-use, triple-layered polypropylene face masks. The choice of this carbon source was driven by the need to address the increase in single-use waste generated during the recent SARS-CoV-2 pandemic, as the use of face masks was a mandatory protective measure. Two bubble column bioreactors were used, each containing hydrocarbonoclastic consortia sourced from the Port of Veracruz and the Gulf of Mexico. The biodegradation activity of these consortia was assessed by observing the physical appearance of microplastic samples under a stereoscope and a microscope, as well as by calculating the weight loss of polypropylene after 15 days. The results revealed that the consortium from the Gulf of Mexico, with a maturity of 1 year, showed a higher capacity for polypropylene biodegradation, achieving a 19.98% degradation rate. This consortium also demonstrated more stable kinetics during the experimentation period. In contrast, the younger consortium from the Port of Veracruz exhibited a lower biodegradation rate of 3.77% and variable growth kinetics. Hydrocarbonoclastic bacteria identified within the consortia included Pseudomonas aeruginosa, Enterococcus faecalis, and Vibrio parahaemolyticus, among others. The hydrocarbonoclastic consortia have the potential to biodegrade from various forms of plastic waste, including single-use face masks. [ABSTRACT FROM AUTHOR]

Staphylococcus species, traditionally associated with pathogenicity, are gaining attention for their role in environmental bioremediation, particularly nitrate reduction, which is crucial for mitigating eutrophication. In this study, denitrifying, biofilm-forming Staphylococcus strains were isolated from Dal Lake, India. Biofilm formation was quantified using a microtiter plate assay, and extracellular polymeric substances (EPS) were measured by dry weight. Statistical analysis revealed a strong positive correlation between EPS production and nitrate removal efficiency (r = 0.96, p < 0.001), with EPS accounting for 92% of the variance in nitrate reduction (R2 = 0.92). Among the isolates, Staphylococcus epidermidis exhibited the highest nitrate reduction at 87% (SD = 2.3%), followed by S. succinus at 83% (SD = 2.1%), S. equorum at 77% (SD = 2.5%), and Staphylococcus sp. at 70% (SD = 2.8%). The consistency of these findings was confirmed by boxplot analysis, and the regression model's robustness was validated by residual plots showing minimal systematic error. This research work provides the first evidence of the nitrate-reducing capabilities of these Staphylococcus species, underscoring their potential in sustainable bioremediation strategies for aquatic environments. The significant correlation between EPS production and nitrate reduction highlights the critical role of biofilms in enhancing microbial remediation processes. The study not only advances the understanding of Staphylococcus in non-pathogenic roles but also suggests that these strains could be pivotal in bioremediation technologies, potentially influencing future environmental management practices. [ABSTRACT FROM AUTHOR]

Bacteria assume a pivotal role in mitigating environmental issues associated with heavy metals, microplastics, and pesticides. Within the domain of heavy metals, bacteria exhibit a wide range of processes for bioremediation, encompassing biosorption, bioaccumulation, and biotransformation. Toxigenic metal ions can be effectively sequestered, transformed, and immobilized, hence reducing their adverse environmental effects. Furthermore, bacteria are increasingly recognized as significant contributors to the process of biodegradation of microplastics, which are becoming increasingly prevalent as contaminants in marine environments. These microbial communities play a crucial role in the colonization, depolymerization, and assimilation processes of microplastic polymers, hence contributing to their eventual mineralization. In the realm of pesticides, bacteria play a significant role in the advancement of environmentally sustainable biopesticides and the biodegradation of synthetic pesticides, thereby mitigating their environmentally persistent nature and associated detrimental effects. Gaining a comprehensive understanding of the intricate dynamics between bacteria and anthropogenic contaminants is of paramount importance in the pursuit of technologically advanced and environmentally sustainable management approaches. [ABSTRACT FROM AUTHOR]

Microplastics (<5 mm size) continue to be a disruptor in the ecosystem being omnipresent in the various spheres of the earth. While there have been various approaches for their degradation, biological approaches continue to be an emerging technology owing to their reduced stress on the environment and energy efficiency. This review paper encompasses the problems created by these microplastics and specifically focuses on polyethylene terephthalate (PET) that are widely used in the packaging and textile industries. This review paper highlights the various microorganisms used to degrade PET and optimum conditions in which PET degradation was carried out. PET is converted to MHET (mono (2‐hydroxyethyl) terephthalic acid) by extracellular PETase, which is subsequently transferred into the periplasmic region of microorganisms by outer membrane anchored MHETase, which transforms MHET to terephthalic acid and ethylene glycol. Factors affecting PET degradation like temperature, pH, crystallinity and environment have also been analyzed. [ABSTRACT FROM AUTHOR]

Wetlands, refer to the confluence with regards to land and water having a rich biological diversity with multiple purpose. As per the Ramsar Convention, framed in August 2002, East Kolkata Wetlands have been considered to be of global significance. Although inappropriate supervision of these wetlands, has led to the gradual deterioration of this wetland. In this present study, the soil sample was collected from these reclaimed agricultural wetlands of Chowbaga area, of East Kolkata areas with coordinates of 22.5296°N, 88.4207°E. The predominant or lingering bacterial flora was isolated from the soil surrounding the rhizospheric region of Cucurbita sp. and Zea mays and their plant growth promotion properties of the lingering bacterial flora were analyzed. These plant growth promoting rhizobacteria (PGPR) included some species of Bacillus sp. that could augment plant growth by different methodologies like nitrogen fixation, phosphate solubilization, phytohormone synthesis, and siderophore production. One of the bacterial isolates DPP(C) showed highest ability of siderophore production of 37.89% at 48 hours, whereas DCP(A) showed better capability in IAA production of 56.785 μg/mL than rest of the bacterial isolates. These reclaimed agricultural lands were found to have very high quantities of heavy metals, especially lead. All the bacterial isolates, were found to have great potential in lead mitigation, whereby they could adsorb up to 8.28% of lead. Some studies have shown the capability of microbial degradation for bioremediation of organic forms of lead and thereby can be removed from agricultural field for longer period of time. The prospective potential use of PGPR has gradually escalated, since it is one of the best substitutes against the constant usage of chemical fertilizers as well as pesticides. The use of these PGPR is one of the most reliable methods for ensuring sustainable agriculture. Furthermore, in future, the PGPR population will be correlated with the nutrient availability and productivity of the plants. [ABSTRACT FROM AUTHOR]

In acidic groundwater, effectively removing both ammonia nitrogen (NH4+-N) and nitrate nitrogen (NO3−-N) poses a challenge. This study focused on studying the removal of NH4+-N and NO3−-N combined contaminations by zero-valent iron (ZVI) combined with microbial agents in both laboratory and field pilot-scale studies. Laboratory experiments showed that ZVI could reduce the denitrification stage from 15 days to 10 days by increasing solution pH and improving NO3−-N reduction efficiency. In a field pilot test (at Qingyuan, Guangdong Province, China), high-pressure injection pumps were used to inject alkaline reagents to raise the pH to 7~8. Meanwhile, compressors were applied to aerate the groundwater to increase the dissolved oxygen (DO) concentration above 2 mg·L−1. Subsequently, microbial agents of nitrobacteria were injected to initiate aerobic nitrification. As the DO level dropped below 2 mg·L−1, agents of micro-ZVI and denitrifying bacteria were injected to stimulate autotrophic denitrification. Intermittent aeration was employed to modify the redox conditions in the groundwater to gradually eliminate NH4+-N and NO3−-N. However, due to the effect of the low-permeability layers, adjustments in the frequency of remediation agent injection and aeration were necessary to achieve removal efficiencies exceeding 80% for both NH4+-N and NO3−-N. This work aims to overcome the limitations of microbial remediation methods in the laboratory and the field and advance nitrogen pollution remediation technologies in groundwater. [ABSTRACT FROM AUTHOR]

Microbial remediation of organically combined contaminated sites is currently facing technical challenges. White rot fungi possess broad-spectrum degradation capabilities, but most of the studies are conducted on polluted water bodies, and few research focus on the degradation of combined organically contaminated soils. This study aimed to investigate the physiological changes in Trametes versicolor to enhance its simultaneous degradation ability towards benzo(a)pyrene (BaP) and TPH. The results demonstrated that Trametes versicolor, when subjected to liquid fermentation, achieved an 88.08% degradation of individual BaP within 7 days. However, under the combined contamination conditions of BaP and TPH, the BaP degradation rate decreased to 69.25%, while the TPH degradation rate was only 16.95%. Furthermore, the degradation rate of BaP exhibited a significant correlation with the extracellular protein concentration and laccase activities. Conversely, the TPH degradation rate exhibited a significant and positive correlation with the intracellular protein concentration. Solid-state fermentation utilizing fungal agents proved to be the most effective method for removing BaP and TPH, yielding degradation rates of 56.16% and 15.73% respectively within 60 days. Overall, Trametes versicolor demonstrated a commendable capability for degrading combined PAHs-TPH pollutants, thereby providing theoretical insights and technical support for the remediation of organically combined contaminated sites. [ABSTRACT FROM AUTHOR]

Sustainable development is a concept that is based on the development of the human society without compromising the natural resources, which should improve human lives and protect the environment for future generations. The UN Agenda 2030 has set 17 goals aimed to transform the development of humanity in accordance with the environment, and with the social and economic rights. This concept is recognized as one of the most important concepts for the future international development. One of the four main pillars of the Agenda 2030 is a pillar Planet, which consists of five sustainability development goals (SDGs) aiming to clean the pollution on the Earth and set the sustainable use of the Earth's resources. The aim of paper is to demonstrate the role of oil pollution bioremediation in achieving SDGs by assessing the importance of this technology and using microorganisms as natural capacity of the Earth for self-cleaning. This review article highlights the applicability of bioremediation as an oil pollution cleaning technique and reviews the compliance of bioremediation with the SDGs. According to this review, bioremediation techniques are an important element which can help in integrated approach to achieve several goals set by the Agenda 2030. Due to the incomplete biodegradation and co-contamination by other chemicals, further research is needed in order to make bioremediation a more effective biotechnological strategy. It is necessary to integrate the Agenda 2030 to university curricula and stream SDGs into scientific funding by opening dedicated calls that contribute to selected SDGs of the Agenda 2030. [ABSTRACT FROM AUTHOR]

The presence of antibiotics in the wastewater is a growing concern, as they tend to bioaccumulate and are increasing the resistance of bacteria. This study investigates the microbial degradation of ciprofloxacin (CIP) in water using Escherichia coli (E. coli) and Enterococcus faecium (E. faecium). This research aims to degrade the ciprofloxacin antibiotic, which is creating multiple problems in the environment and wastewater. Bacterial strains were isolated from wastewater and sludge samples, and their identities were confirmed through 16S rRNA sequencing. The degradation potential was assessed using a shake flask method under varying conditions, including different antibiotic concentrations, temperatures, pH levels, and inoculum densities. E. coli effectively degraded CIP, achieving 90% degradation at 50 mg/L in 18 days, in optimal conditions like a temperature of 37 °C, a pH of 6.5, and an inoculum concentration of 10−8 CFU/mL. However, at higher concentrations (150 mg/L), degradation decreased. Similarly, E. faecium showed a maximum degradation rate of 100% at 50 mg/L of CIP in 18 days, with optimal degradation occurring at 40 °C, a pH of 6.5, and an inoculum density of 10−8 CFU/mL. This study underscores the effectiveness of selected microbial strains in bioremediation processes, highlighting their potential application in mitigating antibiotic pollution in aquatic environments. This is the preliminary study to explore the potential of isolated bacteria to degrade CIP, and their degradation ability can be utilized to develop a CIP-contaminated wastewater treatment plant. [ABSTRACT FROM AUTHOR]

Fluoranthene (Flu) is an ubiquitous, carcinogenic, high molecular weight tetracyclic polycyclic aromatic hydrocarbon whose increased accumulation in soil is matter of concern worldwide. In urban areas, an upsurge in population, industrialization and transportation activities has led to significant increase in the concentration of soil pollutants, such as Flu. Consequently, its concentration exceeds the carcinogen exposure risk thresholds in many urban areas, highlighting the urgent need for cost-effective and sustainable mitigation strategies. There has been an increased interest in microbe-mediated remediation in order to address this soil pollutant. In the present study, three Flu-degrading bacteria, Bacillus sp. VMF1, Bacillus sp. VMF2 and Bacillus licheniformis VMF3, have been isolated from urban soil of Delhi. Growth kinetic rate of three isolates was examined under a range of conditions of temperature, pH and salinity at five different concentrations of Flu. Additionally, their potential to degrade petroleum hydrocarbons was assessed. All isolates showed > 90% degradation of Flu at different concentrations. GC–MS analysis of broth cultures indicated the presence of compounds such as Dibutyl phthalate and Phenol,3,5-bis(1,1-dimethyl ethyl)- suggesting the involvement of phthalic acid pathway in Flu degradation. All isolates showed high growth kinetics under different pH and temperature condition at higher Flu concentration. Interestingly, these bacteria showed adaptation to high saline conditions, with enhanced growth and degradation efficiency. All isolates demonstrated promising capabilities in degrading petroleum hydrocarbons. Our findings thus underscore their adaptability and efficiency, making them promising candidates for Flu and petroleum hydrocarbon degradation, in diverse range of soil pH, temperature and salinity. [ABSTRACT FROM AUTHOR]

Extensive use of the neonicotinoid insecticides acetamiprid (ACE) and flonicamid (FLO) in agriculture poses severe environmental and ecological risks. Microbial remediation is considered a feasible approach to address these issues. Many ACE-and FLO-degrading microorganisms have been isolated and characterized, but few reviews have concentrated on the underlying degradation mechanisms. In this review, we describe the microbial degradation pathways of ACE and FLO and assess the toxicity of ACE, FLO and their metabolites. Especially, we focus on the enzymes involved in degradation of ACE and FLO, including cytochrome P450s, nitrile hydratases, amidases, and nitrilases. Those studies reviewed here further our understanding of the enzymatic mechanisms of microbial degradation of ACE and FLO, and aid in the application of microbes to remediate environmental ACE and FLO contamination. [ABSTRACT FROM AUTHOR]

Textile industries utilize a variety of dyes and chemicals, resulting in wastewater that contains numerous hazardous components. The release of these dyes into aquatic systems poses a serious environmental and harms human health due to their persistence, recalcitrance, and nonbiodegradability. To address this, microbial bioremediation and nano‐photocatalysts are commonly employed for the effective removal of dyes and toxic compounds from textile effluents. This review explores the ecofriendly and efficient use of microbes, such as fungi, yeast, bacteria, and algae, in dye treatment, emphasizing their role in decolorization and degradation. Additionally, microbial remediation is highlighted as a clean, effective, and safe technology for detoxifying azo dyes in wastewater. The review also compares microbial and nanoparticle methods for dye removal from textile wastewater, examining the environmental impact of each approach. Furthermore, we have highlighted challenges and prospects for the development direction and future of this field. [ABSTRACT FROM AUTHOR]

Microbial bioremediation is an advanced technique for removing herbicides and heavy metals from agricultural soil. In this study, the strain Stenotrophomonas pavanii MY01 was used for its ability to degrade glyphosate, a phosphorus-containing organic compound, producing PO43− as a byproduct. PO43− is known to form stable precipitates with heavy metals, indicating that strain MY01 could potentially remove heavy metals by degrading glyphosate. Therefore, the present experiment induced phosphate precipitation from Cu(II) (Hereinafter referred to as Cu2+) and Zn(II) (Hereinafter referred to as Zn2+) by degrading glyphosate with strain MY01. Meanwhile, the whole genome of strain MY01 was mined for its glyphosate degradation mechanism and its heavy metal removal mechanism. The results of the study showed that the strain degraded glyphosate best at 34°C, pH = 7.7, and an inoculum of 0.7%, reaching 72.98% within 3d. The highest removal of Cu2+ and Zn2+ in the test was 75.95 and 68.54%, respectively. A comparison of strain MY01's genome with glyphosate degradation genes showed that protein sequences GE000474 and GE002603 had strong similarity to glyphosate oxidoreductase and C-P lyase. This suggests that these sequences may be key to the strain's ability to degrade glyphosate. The GE001435 sequence appears to be related to the phosphate pathway, which could enable phosphate excretion into the environment, where it forms stable coordination complexes with heavy metals. [ABSTRACT FROM AUTHOR]

Heavy metals are extensively discharged through various anthropogenic activities, resulting in an environmental risk on a global scale. In this case, microorganisms can survive in an extreme heavy metal-contaminated environment via detoxification or resistance, playing a pivotal role in the speciation, bioavailability, and mobility of heavy metals. Therefore, studies on the mechanism for the microbial transformation of heavy metals are of great importance and can provide guidance for heavy metal bioremediation. Current research studies on the microbial transformation of heavy metals mainly focus on the single oxidation, reduction and methylation pathways. However, complex microbial transformation processes and corresponding bioremediation strategies have never been clarified, which may involve the inherent physicochemical properties of heavy metals. To uncover the underlying mechanism, we reclassified heavy metals into three categories based on their biological transformation pathways, namely, metals that can be chelated, reduced or oxidized, and methylated. Firstly, we comprehensively characterized the difference in transmembrane pathways between heavy metal cations and anions. Further, biotransformation based on chelation by low-molecular-weight organic complexes is thoroughly discussed. Moreover, the progress and knowledge gaps in the microbial redox and (de)methylation mechanisms are discussed to establish a connection linking theoretical advancements with solutions to the heavy metal contamination problem. Finally, several efficient bioremediation strategies for heavy metals and the limitations of bioremediation are proposed. This review presents a solid contribution to the design of efficient microbial remediation strategies applied in the real environment. [ABSTRACT FROM AUTHOR]

• Combined with the actual site groundwater characteristics. • Discussed the design of MFCs, including configuration and size, electrode, membranes and separators, contaminants. • Reviewed the progress of research on groundwater removal with MFCs in the last decade. • Considerd the efficiency and practicability of MFCs. Microbial fuel cells (MFCs) have become more prevalent in groundwater remediation due to their capacity for power generation, removal of pollution, ease of assembly, and low secondary contamination. It is currently being evaluated for practical application in an effort to eliminate groundwater pollution. However, a considerable majority of research was conducted in laboratories. But the operational circumstances including anaerobic characteristics, pH, and temperature vary at different sites. In addition, the complexity of contaminants and the positioning of MFCs significantly affect remediation performance. Taking the aforementioned factors into consideration, this review summarizes a bibliography on the application of MFCs for the remediation of groundwater contamination during the last ten decades and assesses the impact of environmental conditions on the treatment performance. The design of the reactor, including configuration, dimensions, electrodes, membranes, separators, and target contaminants are discussed. This review aims to provide practical guidance for the future application of MFCs in groundwater remediation. [Display omitted] [ABSTRACT FROM AUTHOR]

The present study was conducted to promote the remediation of oil-contaminated soils near the Zhidan oilfield using combined plant-microbe treatments・ Two plants, ryegrass (63・ 28%) and alfalfa (59・ 31%), were selected for their significant remediation capabilities in petroleu m-contaminated soil based on their seed tolerance to petroleum-contaminated soil, morphphysiological indices, and their ability to degrade soil petroleum hydrocarbons. A microbial fungicide, ZD, with efficient remediation capabilities for petroleum-contaminated soil, was isolated from the rhizosphere of ryegrass and alfalfa・ The use of ryegrass and alfalfa in conjunction with the composite microbial fungicide ZD for the remediation of petroleum-contaminated soil revealed that an inoculum of 1・ 25% of microbial fungicide ZD yielded a notable effectiveness(78.28%) in the combined plant-microbe remediation of petroleum・contaminated soil. This study successfully obtained plants and microbial agents from petroleum-contaminated soil, and after proper treatment, reused them for the efficient remediation of petroleum-contaminated soil, aligning with the principle of utilizing local resources for remediation purposes, as exemplified by the concept "what is taken from here, is used in here・" [ABSTRACT FROM AUTHOR]

Microbial electrochemical technologies represent innovative approaches to contaminated soil and groundwater remediation and provide a flexible framework for removing organic and inorganic contaminants by integrating electrochemical and biological techniques. To simulate in situ microbial electrochemical treatment of groundwater plumes, this study investigates Cr(VI) reduction within a bioelectrochemical continuous flow (BECF) system equipped with soil‐buried electrodes, comparing it to abiotic and open‐circuit controls. Continuous‐flow systems were tested with two chromium‐contaminated solutions (20–50 mg Cr(VI)/L). Additional nutrients, buffers, or organic substrates were introduced during the tests in the systems. With an initial Cr(VI) concentration of 20 mg/L, 1.00 mg Cr(VI)/(L day) bioelectrochemical removal rate in the BECF system was observed, corresponding to 99.5% removal within nine days. At the end of the test with 50 mg Cr(VI)/L (156 days), the residual Cr(VI) dissolved concentration was two orders of magnitude lower than that in the open circuit control, achieving 99.9% bioelectrochemical removal in the BECF. Bacteria belonging to the orders Solirubrobacteriales, Gaiellales, Bacillales, Gemmatimonadales, and Propionibacteriales characterized the bacterial communities identified in soil samples; differently, Burkholderiales, Mycobacteriales, Cytophagales, Rhizobiales, and Caulobacterales characterized the planktonic bacterial communities. The complexity of the microbial community structure suggests the involvement of different microorganisms and strategies in the bioelectrochemical removal of chromium. In the absence of organic carbon, microbial electrochemical removal of hexavalent chromium was found to be the most efficient way to remove Cr(VI), and it may represent an innovative and sustainable approach for soil and groundwater remediation. Integr Environ Assess Manag 2024;20:2033–2049. © 2024 The Author(s). Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC). Key Points: The research offers valuable insights that can contribute to advancing microbial electrochemical remediation systems designed to reduce Cr(VI) in water‐saturated soils.There were substantial differences from previously reported studies: acclimatization and/or adaptation and transfer of the electroactive bacterial community to Cr(VI) to a bioelectrochemical continuous flow system, no ion exchange membranes, and no nutrients and/or organic carbon added.The research was conducted to simulate most realistically the real conditions of Cr(VI)‐contaminated aquifers, in terms of solid‐to‐liquid ratio, interactions among soil phases, and physicochemical parameters (pH and electrical conductivity).The outcomes achieved in the system for Cr(VI) reduction in water‐saturated soil can demonstrate the feasibility of employing microbial electrochemical technology for the in situ treatment of contaminated aquifers, with interesting implications for economic and environmental sustainability. [ABSTRACT FROM AUTHOR]

In this review, we describe recent developments and strategies involved in the utilization of solid supports for the management of wastewater by means of biological treatments. The origin of wastewater determines whether it is considered natural or industrial waste, and the source(s) singly or collectively contribute to increase water pollution. Pollution is a threat to aquatic and humans; thus, before the discharge of treated waters back into the environment, wastewater is put through a number of treatment processes to ensure its safety for human use. Biological treatment or bioremediation has become increasingly popular due to its positive impact on the ecosystem, high level of productivity, and process application cost-effectiveness. Bioremediation involving the use of microbial cell immobilization has demonstrated enhanced effectiveness compared to free cells. This constitutes a significant departure from traditional bioremediation practices (entrapment, adsorption, encapsulation), in addition to its ability to engage in covalent bonding and cross-linking. Thus, we took a comparative look at the existing and emerging immobilization methods and the related challenges, focusing on the future. Furthermore, our work stands out by highlighting emerging state-of-the-art tools that are bioinspired [enzymes, reactive permeable barriers linked to electrokinetic, magnetic cross-linked enzyme aggregates (CLEAs), bio-coated films, microbiocenosis], as well as the use of nanosized biochar and engineered cells or their bioproducts targeted at enhancing the removal efficiency of metals, carbonates, organic matter, and other toxicants and pollutants. The potential integration of 'omics' technologies for enhancing and revealing new insights into bioremediation via cell immobilization is also discussed. [ABSTRACT FROM AUTHOR]

By constructing a numerical model of groundwater flow in an ionic rare earth mining area, the flow field and runoff characteristics of groundwater were simulating and predicting. The design scheme for groundwater pollution remediation was thus optimized based on the prediction results of flow field and streamline. According to the optimized results, the length of the grout curtain was adjusted from 160 m to 95 m, and the depth was adjusted from 20 m to 0.5 m below the relative waterproof layer, and the top line was adjusted from the surface to 114 m elevation. The injection wells of in-situ chemical coupled microbial remediation engineering were adjusted from uniform layout to centralized layout in heavily polluted areas, ensuring that all groundwater in the remediation period can flow through the injection area. The length of the permeable reactive barriers was adjusted from 56 m to 41.5 m, the depth of the grout wall was increased to 0.5 m below the relative waterproof layer, and the top line elevation extended from the bottom of the repair unit to 101.4 m. Considering the amount of groundwater overflow in the mining area, the scale of ecological ditch treatment was adjusted from 232 m³/d to 262 m³/d. After optimization, groundwater pollution remediation scheme was more scientific, reasonable, and low-cost, which has great reference significance for the formulation of similar groundwater pollution remediation schemes. [ABSTRACT FROM AUTHOR]

After shale gas well sites are exploited, remediation is essential to restore the ecological environment. Effective bioremediation often has long cycles, so reducing this period is a research focus. To elucidate the intrinsic mechanisms between microorganisms and oil removal and to support the acceleration of bioremediation, gas chromatography–mass spectrometry and high-throughput sequencing technologies were utilized. The oil transformation and microbial response mechanisms during the natural remediation process from August to December at an abandoned shale gas well site in Weiyuan County, Neijiang City, Sichuan Province, were analyzed, revealing the directions of microbial succession. The Results showed that from August to September, the greatest degradation of oil components (C10-C20、C21-C30 alkanes) occurred, with Actinobacteriota, Gemmatimonadota, Proteobacteria, Acidobacteriota, Bacteroidota, and Ascomycota playing major roles. Key contributors to oil degradation included Sphingomonas, Flavisolibacter, Ramlibacter, Mortierella, Fusarium, and Rectifusarium. These microorganisms, along with those such as Chloroflexi, Gemmatimonas, Ellin6067, Cercospora, Sarocladium, Preussia, Calyptrozyma, Staphylotrichum, and Exophiala, which facilitate the cycling of nutrients like carbon, nitrogen, and phosphorus, collectively promote the degradation of oil. Moisture content, electrical conductivity, total nitrogen, total phosphorus, and pH affect the activity of oil-degrading microbes and thus oil degradation. Conversely, microbes alter soil chemistry during degradation, impacting those physicochemical properties. This feedback mechanism influences the activity of other oil-degrading microbes, creating a dynamic interaction network. Ultimately, the microbial community shifts towards populations that aid soil ecosystem restoration. This study reveals microbial succession and its role in oil degradation, offering insights for improving and accelerating bioremediation. [ABSTRACT FROM AUTHOR]

High lead (Pb) levels in agricultural soil and wastewater threaten ecosystems and organism health. Microbial remediation is a cost-effective, efficient, and eco-friendly alternative to traditional physical or chemical methods for Pb remediation. Previous research indicates that micro-organisms employ various strategies to combat Pb pollution, including biosorption, bioprecipitation, biomineralization, and bioaccumulation. This study delves into recent advancements in Pb-remediation techniques utilizing bacteria, fungi, and microalgae, elucidating their detoxification pathways and the factors that influence Pb removal through specific case studies. It investigates how bacteria immobilize Pb by generating nanoparticles that convert dissolved lead (Pb-II) into less harmful forms to mitigate its adverse impacts. Furthermore, the current review explores the molecular-level mechanisms and genetic engineering techniques through which microbes develop resistance to Pb. We outline the challenges and potential avenues for research in microbial remediation of Pbpolluted habitats, exploring the interplay between Pb and micro-organisms and their potential in Pb removal. [ABSTRACT FROM AUTHOR]

Copyright of Global Journal of Environmental Science & Management (GJESM) is the property of Global Journal of Environmental Science & Management and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)