Ehsan Gazi, Paul R. Whatley, Maurice D. Walker et al.

Remediation Journal • 2025

ABSTRACT The remediation of urban infrastructure contaminated with an environmentally persistent pathogen requires a large proportion of surfaces to be treated with liquid‐based biocides. Critical to this wide area decontamination effort, will be logistically viable approaches that apply target quantities of formulation to these surfaces while ensuring complete surface coverage over the variety of geometries present. This work quantitatively evaluated the uniformity in delivering formulations at two different target volumes of 1000 and 3700 L/ha, through a range of sprayers, to a representative urban street. Agricultural‐based spray systems were assembled from commercial‐off‐the‐shelf components and mounted onto a quad bike and mobile elevated work platform (MEWP). These provided agile methods for treating pedestrian paving, roads, front gardens, house roofs, and external walls. Also, a combination of person‐worn electric‐ and gasoline‐powered backpack sprayers was evaluated for their use in delivering formulation into dense hedgerows. A remediation strategy was proposed on how the evaluated technologies may be deployed in a system‐of‐systems approach to deliver target doses onto the structures identified in this example street while minimizing contamination spread.

Annie Lee, Stewart H. Abrams, Eric Moskal et al.

Remediation Journal • 2013

Abstract This article presents a case study of the source‐area treatment of tetrachloroethene (PCE) in a low‐permeability formation using zero‐valent iron (ZVI). Evidence of the stimulation of biological reduction processes within the treatment zone occurred. Pneumatic fracturing and injection of microscale ZVI slurry in the overburden and weathered bedrock zones was performed at a commercial brownfields redevelopment site in Maryland. A 20,000‐square‐foot source area impacted with PCE at concentrations greater than 15,000 µg/L was treated at depths ranging from 10 to 70 feet bgs. An average ZVI dosage of 0.0024 iron‐to‐soil mass ratio within the overburden zone led to a 75 percent decrease in PCE mass in less than one year. For the weathered bedrock zone, an average 0.0045 iron‐to‐soil mass ratio resulted in a 92 percent decrease in PCE mass during the same period. The reducing environment and hydrogen generated by the ZVI may have stimulated Dehalobacter populations, as evidenced by concentrations up to 10 4 cells per milliliter measured within the treatment area despite a groundwater pH as high as 9. The biological reductive dechlorination of the chlorinated ethenes explains the temporary increase in trichloroethene and cis ‐1,2‐dichloroethene concentrations. © 2013 Wiley Periodicals, Inc.

Paul E. Flathman, Douglas E. Jerger, Lucy S. Bottomley

Groundwater Monitoring & Remediation • 1989

Abstract On‐site biological cleanup following spills of biodegradable hazardous organic compounds in lagoon, soil, and ground water environments is a cost‐effective technique when proper engineering controls are applied. Biodegradation of hazardous organic contaminants by microorganisms minimizes liability by converting toxic reactants into harmless end products. Three case histories presented in this paper detail: • Bench‐scale evaluation of the potential for biological remediation in the spill site matrix • Field implementation of biological treatment techniques. Cost‐effectiveness, minimal disturbance to existing operations, and on‐site destruction of spilled contaminants are several of the advantages identified for implementing biodegradation as a technique for spill cleanup and environmental restoration.

Jacimaria R. Batista, Tina M. Gingras, Adriano R. Vieira

Remediation Journal • 2002

Abstract Ion‐exchange (IX) resin is perhaps the most promising technology to remove the contaminant perchlorate (ClO 4 − ) from waters. However, ion exchange is only a separation technology that transfers the perchlorate from waters to the waste solutions used to regenerate the resins. The waste solutions contain high perchlorate concentrations, and treatment technologies for these regenerant solutions are needed. In this article, we review the latest knowledge on perchlorate removal by ion‐exchange resins; propose three systems that combine ion‐exchange resins (for perchlorate removal) and biological reduction for treating the waste solutions resulting from resin regeneration; and discuss the challenges and research needed to fully develop the proposed technology. © 2002 Wiley Periodicals, Inc.

Dora M. Taggart, Trent A. Key

Environmental Contamination Remediation and Management • 2024

Abstract Molecular biological tools (MBTs) are used to assess and characterize the microbiology and associated biological processes at contaminated sites, including ecological roles, phylogenetic diversity, and metabolic and co-metabolic capabilities related to contaminant biodegradation and biotransformation. MBTs have changed our approach to the assessment and remediation of petroleum hydrocarbons in the environment. In contaminated-site management, several MBTs and stable isotope analysis methods can be used to measure the presence, abundance, and activity of petroleum hydrocarbon-degrading microorganisms and transformation pathways: (1) quantitative polymerase chain reaction (qPCR) to quantify microorganisms and genes encoding enzymes for biodegradation or biotransformation, (2) DNA sequencing to comprehensively identify the microorganisms presence and microbial community structure, (3) stable isotope probing (SIP) provides conclusive evidence of biodegradation through the use of 13 C-labeled surrogate compounds of petroleum hydrocarbons that microbes use as carbon and/or energy sources, and (4) compound-specific isotope analysis (CSIA) measures the ratio of naturally occurring stable isotopes within a contaminant to indicate (bio)degradation. This chapter discusses the use, benefits, and limitations of MBTs. Several real-world case studies are provided to demonstrate how to investigate the biodegradation of petroleum hydrocarbon constituents under varying field conditions to better characterize governing biogeochemical processes and to better inform remedial decisions.

Elvis G. Ngwenya, Maud Walsh, Caroline A. Metosh‐Dickey et al.

Remediation Journal • 2006

Abstract Biological and physicochemical approaches were utilized in a treatment train for acid mine dis charge (AMD) waters. Anaerobic bioreactors, chemical precipitation reactors, and biopolymer chelation reactors, operated in static, semicontinuous, and continuous flow modes, removed significant quantities of metals and sulfates associated with AMD water. Static tests indicated accept able copper removal via precipitation by generation of hydrogen sulfide in anaerobic reactors. However, low pH affected the biopolymer coating in the chelation reactor, resulting in loss of bed surface. Corrections of AMD to pH > 7 resulted in some metal precipitationprior to biopolymer treatment. A series of static semicontinuous tests at pH 5.0 provided improved metal and sulfate removal. Copper (Cu + ) was reduced to trace concentrations, while manganese (Mn + ), although reduced, proved to be the most recalcitrant of the metals. © 2006 Wiley Periodicals, Inc.

Alan F. Rozich

Remediation Journal • 1994

Abstract Biological systems are frequently used for wastewater treatment and hazardous materials remediation. The primary problem cited with these systems is the lack of a structured methodology that can be used to predict the performance for design and operational applications. The purpose of this article is to present the background and examples of a novel methodology for analyzing biological treatment processes. This technique is much more cost‐effective and accurate than conventional approaches. The article will address applications for both biological wastewater treatment systems and bioremediation processes.

Troy Fowler, Bruce Thompson, Jim Mueller

Remediation Journal • 2011

Abstract Remediating environmental contamination by either biological or chemical methods typically results in the generation of temporary chemical intermediates as part of the process. These intermediate compounds may be related to either contaminant degradation pathways or reactions generated from the amendment itself. This article summarizes previously researched pathways and representative case studies discussing the authors' experience in generating relatively high concentrations of acetone and 2‐butanone (also referred to as methyl ethyl ketone [MEK]) during both biological and chemical treatments. Experience shows that even relatively high concentrations of acetone and MEK intermediates are quickly attenuated and prove not to be a hazard outside of the treatment area. © 2011 Wiley Periodicals, Inc.

Dora M. Taggart, Kate Clark

Remediation Journal • 2021

Abstract Stakeholders of petroleum hydrocarbon‐contaminated (PHC) sites aim to meet remediation goals cost‐effectively. But contaminated sites are typically complex, and when inefficient remediation strategies are implemented, time and money are wasted. Various strategies can be implemented for site remediation and almost all at some point involve a biological component. Therefore, during site characterization, seeing the complete picture by obtaining multiple lines of evidence—chemistry (concentrations of contaminants and daughter products), geochemistry (redox status, electron acceptors, electron donors), microbiology (species and their genes for catalyzing biodegradation of reactions, i.e., functional genes), and the contaminant degradation ongoing at baseline (stable isotope methods)—is critically important for selecting the best remediation strategy. Additionally, molecular biological evidence is important for monitoring treatment progress and informing decisions to retreat, change treatments, or transition to monitored natural attenuation.

Marina Robas, P. Jiménez, D. González et al.

International Journal of Environmental Research and Public Health • 2021

Soil pollution from heavy metals, especially mercury, is an environmental problem for human health. Biological approaches offer interesting tools, which necessarily involve the selection of organisms capable of transforming the environment via bioremediation. To evaluate the potential use of microorganisms in phytorhizoremediation, bacterial strains were isolated from rhizospheric and bulk soil under conditions of chronic natural mercury, which were identified and characterized by studying the following: (i) their plant growth promoting rhizobacteria (PGPR) activities; and (ii) their maximum bactericide concentration of mercury. Information regarding auxin production, phosphate solubilization, siderophore synthesis and 1-aminocyclopropane-1-carboxylic acid deaminase (ACCd) capacity of the isolates was compiled in order to select the strains that fit potential biotechnological use. To achieve this objective, the present work proposes the Bio-Mercury Remediation Suitability Index (BMR-SI), which reflects the integral behavior of the strains for heavy metal polluted soil bioremediation. Only those strains that rigorously fulfilled all of the established criteria were selected for further assays.

Chi-Chun Huang, Chih-Ming Liang, Ting-I Yang et al.

PLOS ONE • 2021

Anthropogenic activities accompanied by heavy metal waste threaten the environment. Heavy metal pollution alters the soil microbial community composition, and the microorganisms that adapt to this stress increase in abundance. The remediation process of contaminated soil not only reduces the concentration of heavy metals but also alters the bacterial communities. High-throughput 16S rDNA sequencing techniques were applied to understand the changes in soil microbial communities. Using the remediation approach of the soil mixing, the concentrations of heavy metals in the contaminated areas were diluted and the soil environment was changed. The change of soil environment as a disturbance contributed to the alteration of microbial diversity of the remediated areas. The pH and heavy metals (Cr, Cu, Ni, and Zn) were the most influential factors driving the changes in community structure. The bacterial community structure was significantly different among sample areas. The decrease of heavy metals in soil may be the important factors that changed the microbial composition. This study provides the better understanding of the changes in composition of microbial communities affected by the remediation process in heavy metal-contaminated soil.

E. IbekweS., P. Okerentugba, G. Okpokwasili

International journal of environmental bioremediation & biodegradation • 2020

Mathematical modeling is a method of simulating real-life situations with mathematical equations to forecast their future behaviour. The modeling of the microbiological parameters was done using SPSS 23 for descriptive statistics while E-view 10 software was used for pooled regression model. Crude oil-contaminated soil from Bodo in Ogoniland was sampled for treatment using bioremediation technology and seven treatment options designated as A to G were setup in triplicates in cells. Five were biostimulated with NH4NO3 and KH2PO4 while unamended and heat-treated served as control. The bioremediation lasted for 56 days with 50 % contaminated media amended with 1 % treatment material. The setup was sampled repeatedly at intervals for analysis within the study period. ES had highest THB count on day 28 while FS had the lowest counts on day 56. For hydrocarbon utilizing bacteria (HUB), CS had the highest count on day 42 while FS had the lowest HUB counts on day 56. For all the treatments options on day 0, the total petroleum hydrocarbon (TPH) ranged from 846.25 to 4406 mg/kg while polycyclic aromatic hydrocarbon (PAH) ranged from 2.02 to 202.70 mg/kg. In all the treatments by day 56, the TPH was < 405 mg/kg while PAH was < 6.5 mg/kg. By day 56, the percentage loss of TPH of treatment options as measured with GC-FID were AS (63 %), BS (72 %), CS (76 %), DS (95 %), ES (98 %), FS (59 %) and heat treated GS (47 % ). ES had the highest TPH (4403.91 mg/kg) on day 0 while CS recorded the lowest TPH (93.01 mg/kg) on day 56. By day 56, the percentage loss of PAH of treatments as measured with GC-FID were AS (98 %), BS (97 %), CS (93 %), DS (94 %), ES (96 %), FS (31 %) and heat treated GS (31 %). However, ES had the highest percentage loss (98 %) of TPH followed by DS (95 %) and lastly GS (47 %). FS had the highest PAH (201.67 mg/kg) on day 0 while AS had the lowest PAH (0.04 mg/kg) on day 56. The AS had the highest percentage loss of PAH (98 %) followed by BS (97 %) and lastly FS and GS (31 %). A total of 121 hydrocarbon utilizing bacteria were obtained which include Micrococcus sp 35 (28.93 %), Acinetobacter sp (9.92 %), Pseudomonas sp (28.93 %), Bacillus sp (14.05%), Alcaligenes sp (4.96 %), Proteus sp (1.65 %) and unidentified isolates (11.57 %). Regression model of bacteria showed the effect of time, nitrogen and phosphorous on microbiological and effect of HUB and THB on physicochemical parameters. Time and nitrogen had positive effect on HUB and THB while phosphorous had negative effect. A unit increase in time and nitrogen increased HUB by 0.0545 and 19.8826 while an increase in total phosphorus decreased HUB by 51.83. Time, HUB and THB affected TPH negatively. A unit increase in time, HUB and THB decreased TPH by 30.84, 74.75 and 145.1 unit respectively. These changes and effects by these mathematical models were statistically significant at P¨Cvalue <0.05 and t-values. F-values implied overall models were statistically significant. These models have established that adjusting of limiting nutrients (nitrogen, phosphorous) is key to effective and efficient bioremediation of crude oil-contaminated media.

Wen-Li Cui, Yingying Liu, Wenguang Li et al.

Toxics • 2023

Soil remediation agents (SRAs) such as biochar and hydroxyapatite (HAP) have shown a promising prospect in in situ soil remediation programs and safe crop production. However, the effects of SRAs on soil microbial communities still remain unclear, particularly under field conditions. Here, a field case study was conducted to compare the effects of biochar and HAP on soil bacterial communities in a slightly Cd-contaminated farmland grown with sweet sorghum of different planting densities. We found that both biochar and HAP decreased the diversity and richness of soil bacteria, but they differently altered bacterial community structure. Biochar decreased Chao1 (−7.3%), Observed_species (−8.6%), and Shannon indexes (−1.3%), and HAP caused Shannon (−2.0%) and Simpson indexes (−0.1%) to decline. The relative abundance (RA) of some specific taxa and marker species was differently changed by biochar and HAP. Overall, sweet sorghum cultivation did not significantly alter soil bacterial diversity and richness but caused changes in the RA of some taxa. Some significant correlations were observed between soil properties and bacterial abundance. In conclusion, soil remediation with biochar and HAP caused alterations in soil bacterial communities. Our findings help to understand the ecological impacts of SRAs in soil remediation programs.

Noam Shani, Vasantha Aravinthan, Pierre Rossi et al.

Groundwater Monitoring &amp; Remediation • 2013

Groundwater microbial community samples are traditionally collected using pumping techniques optimized for groundwater chemistry assessment, although the impact of groundwater pumping parameters on apparent bacterial community structures ( BCSs ) is not really known. We therefore studied the impact of pumping lift, flow regime, and tubing material on BCS , which were analyzed by terminal‐restriction fragment length polymorphism (T‐ RFLP ). Ruzicka dissimilarity coefficients were calculated between T‐ RFLP profiles to assess disparities between BCS . Variations in pumping lift, flow regime, and tubing material did not affect the apparent BCS in experiments using a homogenous water system under laboratory conditions showing that the conditions within the tube had no detectable effect on BCS . However, pumping groundwater from aquifer monitoring wells at different flow rates in the field revealed a significant impact on the apparent BCS . Water samples collected from fine sediment were the most affected by the pumping flow rate.

Claudia Campillo-Cora, Daniel Arenas-Lago, Manuel Arias-Estévez et al.

• 2023

Abstract. Chromium (Cr) pollution in soils is a global concern that should be assessed. Pollution Induced Community Tolerance (PICT) methodology is a highly sensitive tool that can directly indicate metal toxicity in the microbial community. Ten soils with a wide range of properties were spiked with 31.25, 62.5, 125, 250, 500, 1000 and 2000 mg Cr·kg-1, in addition to the control. Bacterial growth (using [3H]-leucine incorporation technique) was used to determine PICT, that is, whether bacterial communities developed tolerance in response to Cr additions to different soil types. Some bacterial communities did not grow normally at 1000 or 2000 mg Cr·kg-1, probably due to high Cr toxicity, while others did. Regarding below 500 mg Cr·kg-1, bacterial communities showed two responses depending on soil type: 7 of the 10 studied soils showed increased tolerance to Cr, while for the remaining 3 soils did not develop tolerance to Cr. Furthermore, the Cr level from which bacterial communities developed tolerance was dependent on the soil, i.e. Cr was more toxic in some of studied soils. The Cr effect on microbial communities was mainly determined by Dissolved Organic Carbon (DOC) and the fraction of Cr extracted with distilled water (H2O-Cr) (R2 = 95.6 %). Their effect on Cr in the soil might lead to an increase in toxicity (selection phase of PICT).

Xin Zhang, Hong Qi Wang, Qian Wang et al.

Applied Mechanics and Materials • 2012

Through greenhouse pots experiments, an orthogonal test method was employed here to study the optimum degradation conditions of cold-adapted degrading bacterial and the winter wheat. This orthogonal experiment selected four influencing factors: oil content, bacteria amount, soil moisture content and fertilizer. The results showed that in different stages, the optimum degradation conditions were different. Oil content and the bacterial amount were the two most important factors that influenced the degradation of petroleum hydrocarbons. The impact of fertilizers on the degradation rate increased with time, while water content on the degradation rate decreased with time.

Tatiana V. Minnikova, Sergey I. Kolesnikov, Nikita S. Minin

Bulletin of the Tomsk Polytechnic University Geo Assets Engineering • 2024

Relevance. Soil pollution with oil has a significant impact on soil fertility and productivity when growing crops. During soil remediation, insufficient attention is paid to soil phytotoxicity assessment in terms of the intensity of the initial growth and development of plants. The results of the study of ordinary chernozem phytotoxicity evaluation on the example of winter barley (Hordeum vulgare L.) after remediation with biochar and a bacterial preparation, containing strains of Bacillus &amp; Paenibacillus, are presented. Aim. To evaluate ordinary chernozem integral phytotoxicity after remediation with biochar and a bacterial preparation, containing strains of Bacillus and Paenibacillus. Objects. Ordinary heavy loamy chernozem, under model conditions, which 5% of the soil mass are oil-contaminated. For soil remediation from oil pollution, biochar and a bacterial preparation with Bacillus &amp; Paenibacillus strains were applied in various combinations: independent application of ameliorants, joint application, inoculation of bacterial preparation with Bacillus &amp; Paenibacillus on biochar. The period of soil incubation with biochar and of bacterial preparation with Bacillus &amp; Paenibacillus has a duration of 30 days. Methods. The residual oil content was determined by the method of extraction with carbon tetrachloride with detection on an infrared analyzer. Soil phytotoxicity after remediation was assessed by indicators of the intensity of initial growth and development of winter barley (Hordeum vulgare L.): germination, germination rate, germination energy, germination friendliness, shoot length, root length, shoot phytomass, root phytomass. As a result of determining these indicators, a complex integral indicator of soil phytotoxicity (IIPht) was calculated. Results. The combined use of biochar with of bacterial preparation with Bacillus &amp; Paenibacillus in oil-contaminated soil leads to the most effective reduction in oil content than when self-introduced and inoculated with of bacterial preparation with Bacillus &amp; Paenibacillus on biochar at the recommended and 100-fold dose, the efficiency is 33 and 58%, respectively. Based on the analysis of phytotoxicity, the highest sensitivity of indicators of barley initial growth intensity was established: germination, friendliness and germination rate. With the independent application of biochar and of bacterial preparation with Bacillus &amp; Paenibacillus, the most informative indicators are shoot phytomass, germination and germination rate; with the combined application of biochar and of bacterial preparation with Bacillus &amp; Paenibacillus, germination energy, shoot length and shoot phytomass; with inoculation of of bacterial preparation with Bacillus &amp; Paenibacillus on a biochar, root length, phytomass of shoots and roots. The study of the phytotoxicity of oil-contaminated Haplic Chernozem after remediation made it possible to establish the ecological efficiency and expediency of using only biochar and biochar inoculated with of bacterial preparation with Bacillus &amp; Paenibacillus.

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 &lt; 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 &lt; 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 &lt; 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 &amp; 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.