Discover insights from thousands of peer-reviewed papers on microbial electrochemical systems
A. Sindhuja, C. Kurinjimalar, Gladstone Christopher Jayakumar et al.
Journal of the American Leather Chemists Association · 2020
A new Bacillus species has been isolated and used for treating chrome leather wastes. The activity of Bacillus species is evaluated for the degradability of the Chrome Leather Waste (CLW). An initial CLW substrate concentration at 0.5 and 1%, along with the bacterial strain is studied against the control sample without bacterial strain. The higher proteolytic enzyme production and hydroxyproline release in the CLW containing medium confirms the degradation process, whereas it is significantly less in control samples. The degradation profile of CLW shows higher in 1% CLW as compared to 0.5% CLW. In 1% CLW, the protease activity of the isolated strain has been increased from 1.615 to 5.625 U/mL. In addition to protease activity, the isolated strain also expressed chromate reductase activity. Furthermore, FTIR, TGA, and SEM studies confirm the degradation of leather wastes.
Ernitha Panjaitan, Lamria Sidauruk, Ebsan Marihot Sianipar et al.
JURNAL AGRONOMI TANAMAN TROPIKA (JUATIKA) · 2025
The remediation of heavy metal-contaminated soil is a crucial step in environmental recovery. This study evaluated the effectiveness of bacteria and biochar in reducing lead (Pb) and copper (Cu) contamination in agricultural soil surrounding the Medan Industrial Area. A Factorial Randomized Block Design (RBD) was employed, incorporating two factors: bacteria (Corynebacterium glutamicum and Lactobacillus sp.) at three levels (0 g, 5 g, and 10 g per plant) and biochar application at three levels (0 g, 10 g, and 20 g per plant), using mustard greens (Brassica juncea) as the indicator plant. The observation parameters included biomass and Pb and Cu content in both soil and plant tissue. Data analysis was conducted using ANOVA and the Honestly Significant Difference Test (HSD) at the 5% significance level The results indicated that bacterial treatment at a level of 5 g per plant and biochar at 20 g per plant significantly increased the wet weight per plant, the wet weight per plot, and the wet weight of plant roots when biochar was administered. The concentrations of the heavy metals lead (Pb) and copper (Cu) in soil and plants decreased with increasing levels of bacteria and biochar. The average reduction in Pb in soil and plants due to bacterial treatment was 1.28% and 0.29%, respectively, while the average decrease in Cu content in soil and plants was 1.03% and 0.17%. Biochar treatment reduced Pb in soil and plants by 0.44% and 0.07%, respectively, and Cu by 0.34% and 0.08%. This study demonstrates that bacteria and biochar stabilize heavy metals in contaminated soil.
Analía Alvarez, Claudia Benimeli, Juliana Saez et al.
International Journal of Molecular Sciences · 2012
In the last few decades, highly toxic organic compounds like the organochlorine pesticide (OP) hexachlorocyclohexane (HCH) have been released into the environment. All HCH isomers are acutely toxic to mammals. Although nowadays its use is restricted or completely banned in most countries, it continues posing serious environmental and health concerns. Since HCH toxicity is well known, it is imperative to develop methods to remove it from the environment. Bioremediation technologies, which use microorganisms and/or plants to degrade toxic contaminants, have become the focus of interest. Microorganisms play a significant role in the transformation and degradation of xenobiotic compounds. Many Gram-negative bacteria have been reported to have metabolic abilities to attack HCH. For instance, several Sphingomonas strains have been reported to degrade the pesticide. On the other hand, among Gram-positive microorganisms, actinobacteria have a great potential for biodegradation of organic and inorganic toxic compounds. This review compiles and updates the information available on bacterial removal of HCH, particularly by Streptomyces strains, a prolific genus of actinobacteria. A brief account on the persistence and deleterious effects of these pollutant chemical is also given.
Ishita Biswas, Debanjan Mitra
Futuristic Trends in Biotechnology Volume 3 Book 10 · 2024
Industrial use of chromium leads to the contamination of natural environment with chromium pollution and the hexavalent form is very harmful to the living system compared to the trivalent and other forms. The most sophisticated way of chromium reduction is the use of an enzyme chromate reductase exclusively produced by the bacteria. An insilico sequence and structure analysis of chromate reductase enzyme from three mesophilic bacteria Acetobacter aceti, Escherichia coli, and Pseudomonas putida has been studied. Amino acid variation study indicates a highest number of charged and uncharged residues in P. putida and A. aceti comparedto E. coli. Secondary structure analysis indicates that protein from E. coli contains additional beta-hairpin and beta bugle. Higher number of salt bridges, aromatic-aromatic interactions, cation-pi interactions in P. putida chromate reductase provides its more stability then the other two. Molecular dynamics simulation studies through RMSD and RMSF indicates less fluctuation in case of P. putida chromate reductase while lowest Rg indicates tightly packed nature and lower SASA indicates better folding of the said protein. This is the first reporting on structural and sequence analysis of chromate reductase of the three mesophilic bacteria and among them P. putidaproved to be the most sable one to be used in the industrial level for better chromate alleviation.
Hana Horváthová, Katarína Lászlová, Katarína Dercová
Acta Chimica Slovaca · 2019
Abstract Remediation of polychlorinated biphenyls (PCBs) in minimal mineral water media in the presence of bacterial mixed cultures consisting of several individual strains is proposed. Starting from the fact that the properties and features of bacterial strains in mixed cultures can be supplemented and compensated, two-, three- and seven-membered mixed cultures (MC) were performed. The strains used for the construction of the MC were isolated from the waste canal of a former PCB producer. The highest biodegradation of 70 % of the sum of seven defined PCB congeners was achieved by two-membered MC containing the strains Rhodococcus sp. and Stenotrophomonas maltophilia added in the biomass ratio of 1 : 3 and 3 : 1. PCB biodegradation by a seven-membered MC was lower (58 %) but provided several benefits over the less-membered mixed cultures or the individual strains: similarity to naturally occurring microflora, easier preparation of the inocula, certain and repeatable results. Periodical reinoculation of the water media resulted to PCB biodegradation increase to 65 %. Seven-membered MC was applied to the historically PCB contaminated sediment as well, where a 59 % degradation of the sum of seven PCB congeners was determined.
Huan Wang, Lingui Xue, Yanli Huo et al.
Research Square · 2022
Abstract Many researchers have paid attention to solving the problem of multiple heavy metals pollution in the tailings area. However, the studies only stay at the laboratory level, which cannot completely demonstrate an efficient approach to remediate polluted environment due to iron tailings. This study aimed at investigating the effects and mechanisms of compound bacterial flora combined with peganum harmala to remediate the tailings area of Linze County, Zhangye City, Gansu Province due to the accumulation of numerous heavy metals such as Pb, Cd and Mn. The preliminary experiment was conducted in the laboratory to obtain data that should be compared with the tailings data. Compared with the control, after 84 days of restoration, parameters of the tailings soil inoculated with the compound bacterial flora were improved, pH was decreased from 7.74 to 7.18, the electrical conductivity was decreased by 21.15% ~70.49%, and activities of alkaline phosphatase, sucrase and urease were increased by 95.94%~99.64%、88.42%~98.43%、83.28%~86.95% respectively. The improvement of soil parameters was more evident in the treatment groups inoculated with compound bacterial flora and Peganum harmala . The results of high-throughput sequencing at different remediation stages showed that the structure of the soil microbial community changed after inoculation with compound bacterial flora, but the dominant species remained unchanged, only their relative abundance changed. At the phylum level, the dominant species in T (total tailings soil treatment groups) were Proteobacteria, Bacteroidota and Actinobacteriota, while the dominant species in 3:1 (H: add yellow cinnamon soil treatment groups) were more than Chloroflexi and Acidobacteriota. According to the analysis of Heatmap, the environmental factors such as pH, WHC, EC, Pb, Cd and Mn have evinced a significant impact on the bacterial community structure. This study provides a reference basis for the remediation approach to the soil polluted by different heavy metals.
Tirishya Gota1, Pragya Kulkarni1
Spectrum of Emerging Sciences · 2024
The globe is currently dealing with serious issues related to health and water pollution. Some frequent sources of water contamination are municipal sewage systems and industrial water.This study examined the antibacterial capabilities of CuO NPs made using a green approach, as well as their impact on polluted water. Because of their many uses and unique qualities, copper oxide nanoparticles, or CuO NPs, have garnered a lot of interest in a variety of sectors, including biomedical sciences and nanomedicine. There are several ways to create copper oxide nanoparticles, including chemical, physical, and biological techniques. The physicochemical methods use a lot of energy, are costly, and discharge a lot of hazardous chemicals into the environment. Conversely, the biological approach offers a simple, comfortable, economical, dependable, and environmentally beneficial means of producing copper oxide nanoparticles. Systematic analysis with UV-Vis, FTIR, XRD and Antimicrobial study validated the synthesis of Copper oxide nanoparticles. The bio mediated synthesis of copper oxide nanoparticles is examined in this review, along with their medicinal uses, which include antibacterial, antifungal, and antiviral.
A. Sizencov, E. Sal'nikova
Ekosistemy · 2024
The escalating technogenic burden on the environment has adverse effects on ecological systems at various levels. Heavy metals significantly contribute to environmental contamination due to their strong biological impact and cumulative properties. The search for new methodological approaches to mitigate the consequences of technogenic pollution induced by heavy metals is an urgent task for ensuring the environmental sustainability of the region. Physical and chemical remediation techniques have several drawbacks, such as high costs and incomplete removal, which can lead to secondary contamination. Bacterial remediation is a highly efficient method that ensures a reduction in the level of human-induced pressure on the ecological system: bacteria – water – soil – plant – animal – human. The article examines meta-analytical data on the mechanisms of interaction between bacterial cells and metals, as well as methods of soil bioremediation and assessment of the sorption characteristics of microorganisms from the genus Bacillus sp. The results of empirical studies presented in the review demonstrate significant bioremediation potential of representatives of this group towards essential and xenobiotic elements from the group of heavy metals. Thus, the level of mercury sorption from substrates can reach up to 96.40 % of the applied concentration, lead – up to 99.5 %, cadmium – 98.3 %, arsenic – 98.3 %, nickel – 99.2 %, chromium – 95.0 %, copper – 91.8 % and zinc – 87.0 %, respectively. The research focuses on developing alternative methods that are not only highly efficient but also environmentally friendly for remediating areas affected by human-induced stress, by utilizing bacterial cell populations. The majority of the analyzed works studies use indigenous strains the tolerance to metals and sorption capacity of which are determined by their selection characteristics under conditions of excessive cationic load of metals on their environment.
Daniel Abiriga, Andrew Jenkins, Kristian Alfsnes et al.
bioRxiv (Cold Spring Harbor Laboratory) · 2020
Abstract Literature on microbiome of landfill leachate-contaminated aquifers is scarce despite groundwater contaminations from landfills being common globally. In this study, a combination of microbiological techniques was applied to groundwater samples from an aquifer contaminated by a municipal landfill and undergoing intrinsic bioremediation. Groundwater samples were obtained from three multilevel sampling wells placed along the groundwater flow path in the contaminated aquifer and additionally from a background well located in a nearby uncontaminated aquifer. The samples were subjected to chemical analysis, microbial culturing and characterisation, cell counting by fluorescence microscopy and 16S rRNA metabarcoding. Good concordance was realised with the results from the different microbiological techniques. Samples from the uncontaminated aquifer had both lower cell density and lower microbial diversity compared to samples from the contaminated aquifer. Among the wells located in the contaminated aquifer, microbial diversity increased between the well closest to the landfill and the intermediate well, but was lower at the most distant well. The majority of the cultured microbes represented taxa frequently recovered from contaminated environments, with 47% belonging to taxa with previously documented bioremediation potential. Multivariate redundancy analysis showed that microbial composition was most similar in wells located closer to the landfill, although beta diversity analysis indicated a significant difference in microbial composition across the wells. Taken together with the results of cell counting, culture and metabarcoding, these findings illustrate the effect of landfill leachate on the microbial community and indicate that microbes are capable of hydrocarbon, sulphur, nitrogen, iron and manganese metabolism.
Lakshmi Priya R., V. Gayathri
Ecology, Environment and Conservation · 2025
Glyphosate is a broad spectrum, non-selective herbicide widely used in the agriculture for the control of weed population. Their presence in environment causes persistent negative effects in human health due to its toxicity. Bioremediation of polluted soil is the primary way of eliminating glyphosate from the environment. The aim of this study is to isolate and identify the herbicide (glyphosate) degrading bacteria from the herbicide polluted agricultural soil and to bioremediate the polluted sample by the bacteria isolate. Their efficiency to degrade glyphosate was tested by various tests like enrichment culture technique, minimum inhibitory concentration and degradation in soil.
Samaneh Gohari, Rahim Aali, Hosein Alidadi et al.
Remediation Journal · 2025
ABSTRACT Inorganic mercury from spent fluorescent lamps is classified as hazardous waste and has become a severe concern for the environment. This study aimed to survey the effect of indigenous heterotrophic bacteria from domestic wastewater on the remediation of inorganic mercury. In this study, the mercury from phosphor power was leached and then detoxified using bacterial strains isolated from domestic wastewater. Nitric and hydrochloric acid solutions were applied for mercury leaching. Twenty‐eight bacterial strains were isolated from domestic wastewater on Reasoner's 2A agar. Then, to check the bacterial mercury resistance, these strains were sub‐cultured on a Luria‐Bertani medium amended with mercury chloride. 16S rRNA gene sequencing was used to determine the genus and species of mercury‐reducing bacteria. This method was performed by the polymerase chain reaction (PCR) amplification of 16S rRNA, followed by sequencing. Bacterial strains demonstrating the remediation capacity of mercury were Acinetobacter junii, Aeromonas cariae, Pseudomonas alcaliphila, Pseudomonas marginalis, Aeromonas sanarellii, Klebsiella singaporensis , and Pseudomonas simiae . These strains showed bio‐uptake efficiency within the range of 67.9% to 92.2%. The lowest and highest rates of mercury remediation were related to P. simiae (67.9%) and P. marginalis (92.24%), respectively. The results show that 18 of these 28 bacterial strains displayed resistance to mercury. To determine the bio‐uptake capacity, the bacteria isolated from wastewater were exposed to the mercury leached from the fluorescent lamps, and mercury content was measured by atomic absorption spectrophotometry. The seven bacteria isolated from wastewater reduced the mercury concentration to less than 5 μg/L. The results of this study revealed that sewage heterotrophic bacteria can be used as an efficient and low‐cost method for mercury bioremediation in discarded fluorescent lamps.
Lyndsay Carrigee, Carina Jung, Matthew Carr et al.
· 2025
Microcystins are a class of hepatotoxins produced by some harmful algal bloom–associated cyanobacteria and are the most reported toxins in freshwaters. Their cyclic structure makes them resistant to conventional methods used in water treatment operations (boiling, chlorination, and UV treatment). Some bacteria can naturally degrade microcystins via the mlrABCD cluster, a pathway initiated by the primary enzyme microcystinase (MlrA). MlrA linearizes the cyclic microcystin, greatly reducing its toxicity. Protein fusion was employed to produce a recombinant MlrA enzyme fused to maltose-binding protein ([MBP] MBP-MlrA) and to evaluate long-term enzymatic stabilization and reconstitution for future applications. MBP-MlrA degraded cyclic microcystin in vitro and demonstrated stability across a range of biological pHs. At a concentration of 0.61 ng/μl in buffer, MBP-MlrA achieved and maintained an average degradation rate of approximately 101.95 μM/h/ng of protein across fifteen freeze/thaw cycles. Stability assays demonstrated that enzyme activity was preserved over 5 months at −20°C. Results also demonstrated the effectiveness of MBP-MlrA to linearize microcystin upwards of 55.59 μM/h/ng of protein at the bench scale in both buffer and various freshwater matrices. The presence of the linear metabolite is of concern regarding intermediate toxicity, and future studies to incorporate the MlrB peptidase are discussed.
Amila Henagamage, C.M Peries, G. Seneviratne
Research Square · 2021
Abstract Heavy metal pollution due to excessive use of chemical fertilizers (CF) causes a major damage to the environment. Microbial consortia, closely associated with the rhizosphere are able to remediate heavy metal-contaminated soil by reducing plant toxicity. Thus, this study was undertaken to examine the remedial effects of microbial biofilms against contaminated heavy metals. Fungi and bacteria isolated from soil were screened for their tolerance against Cd 2+ , Pb 2+ and Zn 2+ . Fungal-bacterial biofilms (FBBs) were developed with the highest tolerant isolates and were further screened for their bioremediation capabilities against heavy metals. The best biofilm was evaluated for its rhizoremediation capability with different CF combinations using a pot experiment conducted under greenhouse conditions with potato. Three bacterial and two fungal isolates were selected to develop FBBs upon the tolerance index (TI) percentage. Significantly (P < 0.05) the highest metal removal percentage was observed in Trichoderma harzianum and Bacillus subtilis biofilm under in situ condition. The biofilm with 50% of recommended CF (50CB) significantly (P < 0.05) reduced the soil available Pb 2+ by 77%, Cd 2+ by 78% and Zn 2+ by 62% compared to 100% recommended CF (100C). In comparison to initial soil, it was 73%, 76% and 57% lower of Pb 2+ , Cd 2+ and Zn 2+ , respectively. In addition, 50CB treatment significantly (P < 0.05) reduced the metal penetration into the tuber tissues in comparison with 100C. Thus, it is concluded that T. harzianum–B. subtilis biofilm is an ideal combination to remediate soil contaminated with Cd 2+ , Pb 2+ and Zn 2+ .
C. Yap, S. Peng
American Journal of Biomedical Science & Research · 2019
The use of microbial bioremediation in recovering polluted soils is not a new technology based on many review reports and studies on its efficiencies and on how to increase the effectiveness. In this short paper, we reviewed the advantages and weaknesses of microbial remediation in cleaning up the polluted ecosystems. Based on the identified weaknesses/disadvantages or incompleteness of the microbial remediation by Sharma and Reddy (2004), future studies should focus on how to increase the effectiveness of the bioremediation technology that should further reduce environmental stress on the terrestrial and aquatic ecosystems. Overall, strategies in the future studies for improving the microbial remediation are discussed.
E. Shahsavari, Abdulatif A. Mansur, A. Aburto-Medina et al.
A handbook of environmental toxicology: human disorders and ecotoxicology · 2020
Abstract Our environment is threatened by thousands of contaminants, mainly as a result of human activities and industrialization. These include both inorganic (e.g. heavy metals) and organic compounds (e.g. polycyclic aromatic hydrocarbons, chlorinated hydrocarbons and herbicides). It has been shown that many of these hazardous chemicals cause health problem such as cancer in living organisms. Therefore, removing them from environments and soils represents a key challenge from both ecosystem and human health perspectives. Among the approaches used to remove these pollutants, microbial remediation or bioremediation represents a promising technology that is cost-effective, environmentally friendly and less disruptive than alternative technologies. Bioremediation involves microbes that are present in or added to the contaminated environment which are capable of degrading contaminants, or reducing them to less toxic forms. There are a number of bioremediation techniques, including natural attenuation, bioaugmentation, biostimulation, phytoremediation/rhizoremediation and necrophytoremediation Many factors, such as soil texture, pH, temperature, levels of oxygen, nutrients and the microbial status of the soils, influence the rate and extent of bioremediation along with the type and bioavailability of the contaminants. In this chapter, we highlight the current status of bioremediation, examining the development of techniques used to assess and optimize the degradation of the contaminants.
C. U. Emenike, Miss Jayanthi Barasarathi, A. Pariatamby et al.
Environmental Reviews · 2018
Environmental deterioration is caused by a variety of pollutants; however, heavy metals are often a major issue. Development and globalization has now also resulted in such pollution occurring in developing societies, including Africa and Asia. This review explores the geographical outlook of soil pollution with heavy metals. Various approaches used to remedy metal-polluted soils include physical, chemical, and biological systems, but many of these methods are not economically viable, and they do not ensure restoration without residual effects. This review evaluates the diverse use of plants and microbes in biotransformation and removal of heavy metals from contaminated soil. Mechanisms on how natural processes utilizing plants (phytoremediation) and microorganisms (bioremediation) remove or reduce heavy metals from soil at various levels are presented. This review concludes that remediation technologies are necessary for the recovery of metal-contaminated environments and the prevention of continuous environmentally toxic impacts on living organisms.
Xin Wang, Jianjiang Hou, Wenrui Liu et al.
Journal of Environmental Science and Health, Part B · 2021
Abstract With the development of modern agriculture, the pollution caused by the use of chemical fertilizers and pesticides has become a serious problem, posing a threat to human health and the living environment. The remediation of plant microorganisms has been seen as an economical, effective, and eco-friendly method of cleaning up soils contaminated with organophosphorus pesticides. In this study, white-rot fungi were immobilized by adsorption method, a plant-microbial remediation met was established. The data results show that after 30 days, the combined remediation system for corn microbes increased the rate of chlorpyrifos degradation by 18% compared to the single remediation of the plant, and the rate of combined remediation of ryegrass microbes increased by 23%. The effect of CPF content in soil on the combined remediation is mainly reflected in the significant difference in the number of microorganisms (P < 0.05). In this article, plant-microbial remediation were applied to soil contaminated by CPF, which provides a new idea for the remediation of pesticide-contaminated soil. Combined bioremediation may be a better alternative to mitigate the impact of high pollution on microorganisms at different pollutant concentrations compared to single microbial remediation or phytoremediation.
Miao Hu, Colin Scott
Applied and Environmental Microbiology · 2024
ABSTRACT Per- and polyfluoroalkyl substances (PFAS) are highly fluorinated synthetic organic compounds that have been used extensively in various industries owing to their unique properties. The PFAS family encompasses diverse classes, with only a fraction being commercially relevant. These substances are found in the environment, including in water sources, soil, and wildlife, leading to human exposure and fueling concerns about potential human health impacts. Although PFAS degradation is challenging, biodegradation offers a promising, eco-friendly solution. Biodegradation has been effective for a variety of organic contaminants but is yet to be successful for PFAS due to a paucity of identified microbial species capable of transforming these compounds. Recent studies have investigated PFAS biotransformation and fluoride release; however, the number of specific microorganisms and enzymes with demonstrable activity with PFAS remains limited. This review discusses enzymes that could be used in PFAS metabolism, including haloacid dehalogenases, reductive dehalogenases, cytochromes P450, alkane and butane monooxygenases, peroxidases, laccases, desulfonases, and the mechanisms of microbial resistance to intracellular fluoride. Finally, we emphasize the potential of enzyme and microbial engineering to advance PFAS degradation strategies and provide insights for future research in this field.
Dr Ajab Singh
International Journal of Environmental Sciences · 2025
Modern agricultural practices, while enhancing food production, have significantly altered the environment, primarily through excessive use of fertilizers, pesticides, and unsustainable land management techniques. These alterations negatively impact soil health, water quality, and ecosystem stability. Microbial communities, being sensitive to environmental changes, serve as effective bioindicators for assessing the ecological impact of agricultural activities. Additionally, their inherent metabolic versatility positions them as potent agents for bioremediation. This review explores the environmental consequences of contemporary agricultural methods, emphasizing the role of microbial indicators in ecological monitoring and the potential of microbial-based bioremediation techniques. The review further highlights advancements in metagenomics, microbial ecology, and biotechnological applications aimed at restoring environmental balance and promoting sustainable agriculture.
Halima M., Sneha Unnikrishnan, Karthikeyan Ramalingam
Advances in Environmental Engineering and Green Technologies · 2021
Across the globe, in both developed and developing countries, wheat provides the fundamental support for all other important foods. However, due to climate change, environmental stress, soil infertility, etc., the yield of wheat is affected. To overcome these issues, biofertilizers are recommended. They are eco-friendly, cost-efficient, and affordable by marginal farmers too when compared with chemical fertilizers. Biofertilizers are made up of living microorganisms that colonize the rhizosphere to promote plant yield and prevent plant disease. Pesticide degrading strains of bacteria are emerging as the best technique to overcome the negative effect of pesticides. Due to insufficient awareness among farmers, agricultural land and crops are cultivated through chemical fertilizers, which became a major threat to human health and agriculture. On the other hand, the government is implementing several measures in marketing bio-fertilizers for the betterment of agriculture and human health. In this chapter, the significance and future perspectives of biofertilizers have been covered.
Samreen Nazeer, Muhammad Zubair Akram, Madad Ali
Advances in Environmental Engineering and Green Technologies · 2021
Soils are a vital part of agricultural production. Soil health plays a significant role in the best crop production. Nowadays, our lands are under immense pressure. This pressure may be in the form of climatic changes that affect crop productivity or may be due to population increment that forces our current food system to produce more food to meet consumer needs. Climatic changes affect soil sustainability in the wrong way. Salinity, drought, and heavy metals disturb land structure badly. As the population increases, it dramatically impacts the current production system to fulfill the present needs. In all these situations, agricultural soil sustainability is a challenging factor for soil scientists to make our agriculture sustainable because agricultural sustainability couldn't be possible without maintaining soil health. Many approaches are available to improve soil structure and health. Among these, plant growth-promoting rhizobacterium is a good option. It not only improves soil structure but also helps the plants under abiotic stress conditions.
Aman Kumar, Mansi Rani, Abhay Kumar Thakur
Contemporary Advances in Science and Technology · 2024
Heavy metal contamination poses a significant threat to the environment and public health because of its persistent toxicity and the bioaccumulation of pollutants. Microbial remediation, leveraging the metabolic capabilities of microorganisms, has emerged as an efficient and sustainable path to reduce and remove substantial, heavy metal pollution. This chapter provides a comprehensive overview of microbial remediation studies, focusing on the mechanisms used by various bacteria, fungi, and algae to remove toxic substances and immobilize heavy metals. This chapter deals with several biochemical pathways in biosorption, bioaccumulation, biotransformation, and bioprecipitation. The role of genetic engineering and synthetic biology in increasing the microbial ability for targeted heavy metal removal was highlighted. The case studies explained here are the details of the booming field application of microbial remediation and the analysis of challenges and limitations in scaling up these technologies. In this chapter, insight for future research direction emphasizes the need for an interdisciplinary approach to optimize and integrate microbial remediation for its maximum efficacy within the broader environmental management framework discussed in the conclusion.
Joan Mwihaki Nyika
Advances in Environmental Engineering and Green Technologies · 2021
Microalgae are promising tools in improving soil fertility and agricultural production in the era of increased population and the need for food security, which is mostly hindered by climate change. The microbes have the ability to sequester atmospheric carbon dioxide, produce metabolites with many applications in addition surviving and growing in harsh environmental conditions. In this chapter, microalgae species of the cyanobacteria and green algae groups are established as good soil biofertilizers and conditioners which are crucial in nutrient cycling, improved soil structure, and increased soil microbial activity. These are requirements for better crop production. Microalgae are also crucial biocontrol agents that suppress and kill plant pathogens and pests, regulate the production of phytohormones, and in bio-remediation of polluted soils. Their use is therefore a road map to sustainable agriculture and food security. To ensure their optimal use, extensive research is necessary to understand the mechanisms of action behind the benefits.
Raghunath Satpathy
Advances in Environmental Engineering and Green Technologies · 2021
The halogenated hydrocarbons have been widely used by human beings. They are xenobiotic and toxic. The microbes having a specific group of hydrolase enzymes, known as dehalogenases, that actually break the carbon-halogen bonds of the halogenated substances and subsequently convert them into their non-toxic forms. In this chapter, the categories of dehalogenase enzymes possessed by microorganisms are narrated. The overall source, mechanism of catalysis, and structural aspects of the haloalkane dehalogenase enzymes have been discussed with special focus to the bioremediation of 1, 2 dichloroethane.
Haozhe Zheng
Highlights in Science, Engineering and Technology · 2022
With the growing problem of oil seepage from gas stations around the world, remediation of oil-contaminated soils is receiving increased attention. Microbial electrochemical techniques have been shown to remove hydrocarbons from soil. Microbial fuel cells (MFC) show a strong potential to immobilize and dissipate contaminants using microorganisms. In this context, this review briefly introduces the conventional methods for remediation of petroleum soil contamination, focusing on the effects of different factors and configurations on the effectiveness of MFC remediation. Compared to traditional remediation methods, applying MFC to petroleum leaks in gas stations has better environmental and economic benefits. It does not require the application of chemicals or ex situ remediation of the soil, which largely reduces the cost and does not cause secondary pollution to the surrounding environment such as soil or atmosphere. In the long term, this technology has a good potential to enhance the remediation effect by changing the applied electric field, soil texture, and petroleum degrading bacteria. In addition, making soil MFC simultaneously achieve combined remediation of petroleum hydrocarbons and other contaminants remains to be studied. Finally, this paper emphasizes that there are few practical applications about MFC site remediation and there is a need to conduct site tests with large scale. If the pilot-scale tests are similar to the laboratory-scale treatment results, the technology will gain more popularity.
Mohd Faheem Khan
Processes · 2025
Fluorinated xenobiotics, such as per- and polyfluoroalkyl substances (PFAS), fluorinated pesticides, and pharmaceuticals, are extensively used across industries, but their extreme persistence, driven by the high carbon–fluorine (C–F) bond dissociation energy (~485 kJ/mol), poses serious environmental and health risks. These compounds have been detected in water, soil, and biota at concentrations from ng/L to µg/L, leading to widespread contamination and bioaccumulation. Traditional remediation approaches are often costly (e.g., EUR >100/m3 for advanced oxidation), energy-intensive, and rarely achieve complete degradation. In contrast, microbial defluorination offers a low-energy, sustainable alternative that functions under mild conditions. Microorganisms cleave C–F bonds through reductive, hydrolytic, and oxidative pathways, mediated by enzymatic and non-enzymatic mechanisms. Factors including electron donor availability and oxygen levels critically influence microbial defluorination efficiency. Microbial taxa, including bacteria, fungi, algae, and syntrophic consortia, exhibit varying defluorination capabilities. Metagenomic and microbial ecology studies continue to reveal novel defluorinating organisms and metabolic pathways. Key enzymes, such as fluoroacetate dehalogenases, cytochrome P450 monooxygenases, reductive dehalogenases, peroxidases, and laccases, have been characterised, with structural and mechanistic insights enhancing the understanding of their catalytic functions. Enzyme engineering and synthetic biology tools now enable the optimisation of these enzymes, and the design of microbial systems tailored for fluorinated compound degradation. Despite these advances, challenges remain in improving enzyme efficiency, broadening substrate specificity, and overcoming physiological constraints. This review emphasises the emerging promise of microbial defluorination as a transformative and green solution, uniquely integrating recent multidisciplinary findings to accelerate the development of sustainable microbial defluorination strategies for effective remediation of fluorinated xenobiotics.
Arunima Nayak, Brij Bhushan
Advances in Environmental Engineering and Green Technologies · 2021
Rapid industrialization, urbanization, and use of modern agricultural practices have resulted in the rise in pollutant levels in soil. In this context, nano-bioremediation has emerged as a new tool for controlling soil pollution by the application of nanomaterials with subsequent use of bioremediation. Due to its cost-effectiveness, eco-friendliness, and sustainability, the use of bioremediation in soil reclamation has rapidly gained prominence. Nanomaterials have helped in remediating toxic soil environments, thereby improving microbial activity and bioremediation efficiency. The overall time as well as costs are greatly reduced. The major limitation of this technology is its longer treatment time and its ineffectiveness for a wide range of pollutants. The chapter has an aim to present an overview of the recent advances and applications in the field of nano-bioremediation of various polluted areas of the environment. Different classes of nanomaterials along with their properties as well as application towards removal of soil pollutants will be addressed.
Rupesh Dutta Banik, Pritha Pal, Sibashish Baksi
Journal of Survey in Fisheries Sciences · 2023
Meeting environmental regulations for both liquid and solid wastes are produced during the manufacture of leather items is one of the long-term issues facing the leather industry. Insufficient treatment of these wastes will cause environmental pollution and endanger human health. Trimmings have generally been underutilized among other trash that are produced. Hair is not utilized, however collagen found in trims and garbage. Many organic and inorganic particles together with the discharge of suspended or gas-solid oil and grease, nitrogen-containing compounds, and heavy metals either by themselves or in their reduced salt form, chlorides, sulphates, chemical oxygen demand (COD) and total dissolved solids (TDS) are all considerably generated and influenced by tanning operations. Formaldehyde used in the production of finished leather that are difficult to biodegrade and can cause the production of free formaldehyde, a recognized carcinogen. Microbial bioremediation is a novel technique that may be used in a variety of soil and water environments due to microorganisms' adaptability to remove hazardous pollutants that could offer a safer and affordable strategy. The pollution profile of leather industries, microbial bioremediation for pollution reduction from diverse ecological lattices and interactions between the microbes and contaminants has received substantial attention in this review.
Himanshi Verma, Meghna Jindal, Shabir A. Rather
Advances in Environmental Engineering and Green Technologies · 2021
The soil is a repository of microorganisms such as bacteria, fungi, algae, and protozoa. Among these, more bacteria are found, most of which are located in the rhizosphere region of the soil. The rhizosphere, under the direct control of plant root secretions, is the complex, narrow area of the soil. It is densely populated with microorganisms (mostly bacteria) that interact with the plants. These interactions influence the growth of the plant directly or indirectly. Plant growth-promoting rhizobacteria (PGPR) inhabiting the rhizosphere colonizes the plant roots and increases plant growth via different mechanisms. Iron is an essential micronutrient required by almost all life forms including plants. Oxidation of Fe2+ (soluble) to Fe3+ (insoluble) due to the soil's aerobic conditions limits its bioavailability. Siderophores are selective low molecular weight ferric ion chelators secreted by bacteria to acquire iron from the surrounding. They bind to iron (Fe3+) with high specificity as well as high affinity. By helping the insolubilisation of iron, it promotes the growth and yield.
Rajalakshmi Sridharan, Veena Gayathri Krishnaswamy
Advances in Environmental Engineering and Green Technologies · 2021
Industrialization led to an increase in chemicals in the environment. The soil absorbs these chemicals and holds them for years until treated. The action of bacteria, fungi, and algae utilize the pollutants and generate energy. The bioremediation contains a diverse treatment process, but the effectiveness of the bioremediation increases by the enzymatic action. Laccase, a copper-containing enzyme, is versatile and oxidizes complex organic compounds without generating reactive oxygen species (ROS). This process is carried by laccase-mediated systems (LCMs) controlled by low redox potential. The presence of redox mediators oxidizes the chemical compounds at the higher rate, making laccase degradation of the pollutants effectively. The chapter provides a glimpse of soil bioremediation by bacteria and fungi as individual species and symbiotic species, the production of laccase enzyme by bacteria and fungi, methods adopted to enhance the enzyme activity, and degradation of pollutants in soil.
Arpitha Chikkanna, Devanita Ghosh
Research Anthology on Emerging Techniques in Environmental Remediation · 2022
Microorganisms play very important role in elemental and mineral chemistry on earth surface. Along with the major biogeochemical cycles such as Carbon, Nitrogen, Sulphur and Phosphorus, which are crucially involved in thermodynamic balances in earth system, microbes are also involved in trace metal cycling. The organic carbon sustaining the indigenous microbial communities critically controls these microbial processes. A large number of the microbial communities are able to form a wide variety minerals, of which many have only biogenic origin and cannot be formed inorganically. Microbes also play a critical role in dissolution of minerals; a process which not only helps in soil formation and the transport of nutrients to higher trophic levels, but can also have many important industrial roles. Thus, in these metabolic activities, microorganisms contribute to the geological phenomenon of the transformation of metals and minerals. This chapter focuses on the role of various microbial metabolic processes that are involved in mineralization and mineral dissolution and the consequences involved with it.
Md. Idrish Raja Khan
Advances in Environmental Engineering and Green Technologies · 2021
Mycoviruses are obligate parasites of fungi and can infect the majority of the fungal groups. They remain mysterious to various communities throughout the globe. Mycoviruses are responsible for certain changes in fungal hyphae, which could be asymptomatic and may cause a reduction or elimination of the virulence capacity of fungal hosts by the process called hypovirulence. Such fungal-virus system could be valuable for the development of novel biocontrol approaches against fungal pathogens for the development of a sustainable environment. There are adequate reports where mycovirus has been employed as a biocontrol approach against the pathogenic fungi in the fields of agriculture and other allied sciences. The prime focus of this review is to emphasize naturally available mycoviruses and strategies to adopt the mycovirus therapy which could serve as an excellent alternative strategy against chemical prophylactic and therapeutic approaches.
Ruiyi Qu
Theoretical and Natural Science · 2024
Abstract. Soil pollution is a global environmental problem that poses a threat to ecological balance and human health. Microbial soil remediation is an eco-friendly technology that utilizes microorganisms to degrade or transform soil pollutants. Due to some drawbacks of traditional soil remediation methods, microbial remediation method has become a hot research topic nowadays. In recent years, the development of genomics analysis technology has greatly promoted the progress of microbial remediation research, and the use of genomics approach is free from the technical constraints of traditional research and can efficiently obtain the relative abundance of microbial communities and other information. In this paper, we reviewed the application of genomics in microbial soil remediation, and discussed the genomic analysis of several examples of heavy metal contaminated soil remediation, which provides a reference for researchers to quickly screen analytical methods in the field of microbial soil remediation, and reveals the biological significance of genomics analytical techniques.
Avni Jain, Neha Singh, Suphiya Khan
Advances in Environmental Engineering and Green Technologies · 2021
The demand for the development of eco-friendly, sustainable, and adaptable technologies for the disinfection of the environmental contaminants is increasing nowadays. Nano-bioremediation is one such technique that has made possible the use of biosynthetic nanoparticles for soil pollution remediation. It is an effective, efficient, and feasible method for revitalizing soil potential and rendering it pollution free. Pollutants present in soil are a great threat to soil biota, environment, and in fact human health. Nanomaterials exhibit the unique chemical and physical properties because of which they have always received attention in the growing era of bioremediation. Use of nanotechnology for bioremediation is one such technology as it focuses mainly on the interaction between the contaminants, the microorganisms, and the nanomaterials being used for both the positive (i.e., stimulating) and negative or toxic environmental effects. Thus, this chapter focuses on the need to recover the polluted soil and application of nano-remediation technology for restoring soil's cultivation capacity.
Amrendra Kumar, Swati Agarwal
Advances in Environmental Engineering and Green Technologies · 2021
Microbial products are being used from ages in known as well as unknown forms. Some common products harvested from microbes include proteins, amino acids, antibiotics, antibodies, secondary metabolites, organic acids, lipids, and so on. It also includes antivirals, polymers, surfactants, enzyme inhibitors, nutraceuticals, and many industrial and agricultural products. Moreover, sometimes the whole single celled microbes are harvested as a rich source of protein called single cell proteins. In a nutshell, all these products cover almost every economic sector like food, feed, agriculture, healthcare, fuel, textile, and pharmaceutical. Hence, these microbial products have serious socio-economic impressions and have unleashed enormous possibilities in terms of commercial production. However, only a small fraction of microbial products are exploited, and a larger chest remains to be achieved. In the chapter, the importance of microbes in the production of proteins, enzymes, and secondary metabolites are discussed in detail with special emphasis on sustainable agriculture.
R. Gayathri, J. Ranjitha, V. Shankar
Bioremediation for Environmental Pollutants · 2023
Chemical elements with an atomic mass unit ranging from 63.5 – 200.6 (relative atomic mass) and a relative density exceeding 5.0 are generally termed as heavy metals. Since they are non-biodegradable inorganic contaminants, physical and chemical methods of degradation are ineffective. Heavy metals cannot be degraded easily due to their physical and chemical properties, such as the rate of oxidation &amp; reduction reactions, rate of solubility, formation of complexes with other metal ions, etc. They are flexible, and easily accumulated in the environment. In the case of bioaccumulation, they are highly lethal to the organisms. The process of removal of toxic and hazardous material from the environment using plants and microorganisms is termed bioremediation. The disposal of toxic contaminants using plants is termed phytoremediation. Microbial bioremediation consists of the removal of toxic elements with the application of microorganisms during which the toxic substance is converted into either end products or nontoxic and non-hazardous forms or recovery of metals.&nbsp;<br>
Junqia Kong, Zhibin He, Chen Longfei et al.
· 2021
Lacking of systematic evaluations in soil quality and microbial community recovery after different amendments addition limits optimization of amendments combination in coal mine-soils. We performed a short-term incubation experiment over 12 weeks to assess the effects of three amendments (biochar: C; nitrogen fertilizer at three levels: N-N1~N3; microbial agent at two levels: M-M1~M2) based on C/N ratio (regulated by biochar and N level: 35:1, 25:1, 12.5:1) on soil quality and microbial community in the Qilian Mountains, China. Over the incubation period, soil pH and MBC/MBN were significantly lower than unamended treatment in N addition and C+M+N treatments, respectively. Soil organic carbon (SOC), total nitrogen (TN), available nitrogen (AN), available phosphorus (AP), available potassium (AK), microbial biomass carbon (MBC) and microbial biomass nitrogen (MBN) contents had a significant increase in all amended treatments (P<0.001). Higher AP, AK, MBC, MBN and lower MBC/MBN were observed in N2-treated soil(corresponding to C/N ratio of 25:1). Meanwhile, N2-treated soil significantly increased species richness and diversity of soil bacterial community (P<0.05). Principal coordinate analysis further showed that soil bacterial community compositions were significantly separated by N level. C-M-N treatments (especially at N2 and N1 levels) significantly increased the relative abundance (>1%) of the bacterial phyla Bacteroidetes and Firmicutes, and decreased the relative abundance of fungal phyla Chytridiomycota (P<0.05). Redundancy analysis illustrated the importance of soil nutrients in explaining variability in bacteria community composition (74.73%) than fungal (35.0%). Our results indicated that N and M addition based on biochar can improve soil quality by neutralizing soil pH and increasing soil nutrient contents, and the appropriate C/N ratio (25:1: biochar+N2-treated soil) can better promote mass, richness and diversity of soil bacterial community. Our study provided a new insight for achieving restoration of damaged habitats by changing microbial structure, diversity and mass by regulating C/N ratio of amendments
Shenaz Sultana Ahmed, Popy Bora
bioRxiv (Cold Spring Harbor Laboratory) · 2023
ABSTRACT Growing brinjal ( Solanum melongena L.) in a soil polluted with organophosphorus pesticide (OP) residues coupled with an additional threat of wilt disease caused by Ralstonia solanacearum ( Rs ), pose a formidable management challenge for residue free crop production. Our study aimed at identifying efficient OP-degrading bacteria (OPDB) and their compatibility with microbial bio-control agents (MBCA) for twin objective of microbial degradation of OP -residues and reduction in incidence of bacterial wilt of brinjal in OP-contaminated soil. As many, ten bacterial isolates showing OP-degrading potential were recovered through colony growth in mineral salt (MS) - medium treated with 25 ppm chlorpyriphos. Efficient isolates displaying growth up to 700ppm chlorpyriphos were further screened for OP-degradation, leading to identification of two most efficient OPDB, Acromobacter marplatensis [MW397524] ( Am ) and Pseudomonas azotoformans [MW397525] ( Pa ). These two isolates having in vitro compatibility with each other, showed further compatibility with two most widely used MBCA, viz., Pseudomonas flourescens [KT258013] ( Pf ) and Trichoderma harzianum [ON364138] ( Th ), facilitating the development of consortium having extended functional corridor. The response of combination of OPDB + MBCA( Am + Pa + Pf + Th ) showed 80% lower percent wilt incidence (PWI), 2.8 times higher fruit yield of brinjal, and 15-25% lower OP-residues over un-inoculated control treatment. Our studies, hence, put forward a strong unified delivery mechanism of OPDB and MBCA as a part of green technology for chemical residue -free vegetable production in contaminated soils. IMPORTANCE Microbes isolated from crop rhizospheres are known to exhibit multiple functions (plant growth promotion, antagonism against soil borne pathogens e.g., Rs, and acaricidal properties) depending upon type of stimuli by regulating the plant defense. Considering the limited past efforts on twin objective of cleaning up the pesticide residues accumulated in the soil (microbial removal of pesticide residues) and providing an additional safeguard against soil borne pathogen causing bacterial wilt in brinjal to collectively develop a microbial consortia mediated crop production system, devoid of any chemical residues. Such an effort adds strength to organic production system on pesticide contaminated soils. In the present study, we succeeded in identifying two most effective chloropyrifos residues degrading OPDB having compatibility two MBCA for developing consortia formulation, which aided in developing pesticide residue free soil, neutralising bacterial wilt pathogen ( Rs ), and creating a better nutrient supply for a well deserved production system. Such efforts would pave the way for developing more robust microbial formulations (with emphasis on entomopathogenic application) having dynamic microbial functions to replace any futuristic use of agrochemcials.
G‐Y. Rhee, Y‐C. Cho, E.B. Ostrofsky
Remediation Journal · 1999
Abstract The extent of natural dechlorination varies widely in sediments and fails to reach its maximum potential. Recent laboratory and field studies have suggested that the potential for further dechlorination is low in the Hudson and St. Lawrence Rivers. Laboratory investigations have also indicated that polychlorinated biphenyl (PCB) dechlorination is directly coupled to the growth of dechlorinating microorganisms in that: (a) there was no growth of dechlorinating microorganisms below the threshold concentration, (b) the rate of chlorine removal per gram sediment was significantly correlated to the growth rate of the microorganisms, (c) the negative effect of lower moisture levels on dechlorination was correlated to the microorganism death rate, and (d) the extent of natural dechlorination in the St. Lawrence River appears to be related to the in‐situ population size of dechlorinators. There also appear to be many dechlorinating populations, each with different requirements and competence. Therefore, the growth enhancement of these microorganisms is the key to promoting PCB dechlorination either in situ or ex situ. © 1999 John Wiley & Sons, Inc.
Kumud Dubey, K. P. Dubey
Advances in Environmental Engineering and Green Technologies · 2021
Bauxite residue (red mud) is an industrial waste bye product of Alumina industry. It is toxic and highly alkaline in nature having heavy metals. Its disposal is the paramount environmental issue in Alumina industry. In the present study, bioremediation of red mud was carried out through cyanobacteria amendments and plantation. Two cyanobacterial species (viz. Phormidium and Oscillatoria) were found promising after studying their effect on physico-chemical characteristics of red mud. Seeds of selected tree species (viz. Dalbergia sissoo, Prosopis juliflora, Acacia auriculiformis, Pithecellobium dulce, Cassia siamia) were procured, and a nursery of these tree species was raised. Performances of two cyanobacteria (viz. Phormidium and Oscillatoria sps.) in combinations with PSB and VAM on red mud are very encouraging and hold considerable promise for bioremediation and revegetation of red mud. Inoculated seedlings of P. juliflora, P. dulce, A. auriculiformis, and C. siamia performed well for red mud revegetation.