Christopher W. Kaplan, Brian G. Clement, Alice Hamrick et al.

Remediation Journal • 2003

<jats:title>Abstract</jats:title><jats:p>A pilot‐scale land treatment unit (LTU) was constructed at the former Guadalupe oil production field with the purpose of investigating the effect of co‐substrate addition on the bacterial community and the resulting rate and extent of total petroleum hydrocarbon (TPH) degradation. The TPH was a weathered mid‐cut distillate (C10‐C32) excavated from the subsurface and stockpiled before treatment. A control cell (Cell 1) in the LTU was amended with nitrogen and phosphorus while the experimental cell (Cell 2) was amended with additional complex co‐substrate—corn steep liquor. During the pilot LTU operation, measurements were taken of TPH, nutrients, moisture, aerobic heterotrophic bacteria (AHB), and diesel oxidizing bacteria (DOB). The bacterial community was also assayed using community‐level physiology profiles (CLPP) and 16S rDNA terminal restriction fragment (TRF) analysis. TPH degradation in both cells was characterized by a rapid phase of degradation that lasted for the first three weeks, followed by a slower degradation phase that continued through the remainder of the project. The initial rate of TPH‐degradation in Cell 1 (−0.021 day<jats:sup>−1</jats:sup>) was slower than in Cell 2 (−0.035 day<jats:sup>−1</jats:sup>). During the slower phase, degradation rates in both cells were similar (−0.0026 and −0.0024 respectively). AHB and DOB counts were similar in both cells during the fast degradation phase. A second addition of co‐substrate to Cell 2 at the beginning of the slow degradation phase resulted in an increased AHB population that lasted for the remainder of the project but did not affect TPH degradation rates. CLPP data showed that co‐substrate addition altered the functional capacity of the bacterial community during both phases of the project. However, TRF data indicated that the phylogenetic composition of the community was not different in the two cells during the fast degradation phase. The bacterial phylogenetic structure in Cell 2 differed from Cell 1 after the second application of co‐substrate, during the slow degradation phase. Thus, co‐substrate addition appeared to enhance the functional capacity of the bacterial community during the fast degradation phase when the majority of TPH was bioavailable, resulting in increased degradation rates, but did not affect rates during the slow degradation phase when the remaining TPH may not have been bioavailable. These data show that co‐substrate addition might prove most useful for applications such as land farming where TPH is regularly applied to the same soil and initial degradation rates are more important to the project goals. © 2003 Wiley Periodicals, Inc.</jats:p>

Pei Hao Li, Kun Wang, Zhong Jin Wang

Advanced Materials Research • 0

<jats:p>Bio-deposition has led to the exploration of remediation and improvement technique in the field of cementitious materials. The aim of this study was to investigate the effects of bio-deposited carbonate on parameters affecting concrete properties and the effects of bio-deposition on the durability of concrete specimens. The remediation efficacy of cracks in concrete was studied through compressive strength test and flexural failure test. Water absorption and the resistance towards carbonation of concrete were analyzed by water absorptivity test and concrete accelerated carbonation test, respectively. Experimental results show that bio-deposition is able to make the improvement in concrete compressive strength and the remediation of cracks. Bacterial deposition of calcite on the surface of the concrete specimens results in a decrease of capillary water uptake and carbonation rate constant, and an increase in resistance towards degradation processes.</jats:p>

Suneel Chhatre, Hemant Purohit, Rishi Shanker et al.

Water Science and Technology • 1996

<jats:p>Oil spills generate enourmous public concern and highlight the need for cost effective and environmentally acceptable mitigation technologies. Physico-chemical methods are not completely effective after a spill. Hence, there is a need for improved and alternative technologies. Bioremediation is the most environmentally sound technology for clean up. This report intends to determine the potential of a bacterial consortium for degradation of Gulf and Bombay High crude oil. A number of bacteria were isolated from an acclimated semicontinuous reactor fed with crude oil. A four membered consortium was designed that could degrade 70% of the crude oil. A member of consortium produced a biosurfactant, rhamnolipid, that emulsified crude oil efficiently for effective degradation by the other members of consortium. The wide range of hydrocarbonoclastic capabilities of the selected members of bacterial consortium leads to the degradation of both aromatic and aliphatic fractions of crude oil in 72 hours.</jats:p>

Xiao Yan, Bowen Gao, Jianlei Wang et al.

Frontiers in Microbiology • 0

<jats:p>The increased demand for rare earth resources has led to an increase in the development of rare earth mines (REMs). However, the production of high-concentration leaching agents (SO<jats:sub>4</jats:sub><jats:sup>2−</jats:sup>) and heavy metals as a result of rare earth mining has increased, necessitating the removal of contaminants. Here, a series of experiments with different remediation measures, including control (CK), sulfate-reducing bacteria (SRB) alone (M), chemicals (Ca(OH)<jats:sub>2</jats:sub>, 1.5 g/kg) plus SRB (CM-L), chemicals (Ca(OH)<jats:sub>2</jats:sub>, 3.0 g/kg) plus SRB (CM-M), and chemicals (Ca(OH)<jats:sub>2</jats:sub>, 4.5 g/kg) plus SRB (CM-H), were conducted to investigate the removal effect of SO<jats:sub>4</jats:sub><jats:sup>2−</jats:sup>, Pb, Zn, and Mn from the REM soil. Then, a high-throughput sequencing technology was applied to explore the response of bacterial community diversity and functions with different remediation measures. The results indicated that CM-M treatment had a more efficient removal effect for SO<jats:sub>4</jats:sub><jats:sup>2−</jats:sup>, Pb, Zn, and Mn than the others, up to 94.6, 88.3, 98.7, and 91%, respectively. Soil bacterial abundance and diversity were significantly affected by treatments with the inoculation of SRB in comparison with CK. The relative abundance of <jats:italic>Desulfobacterota</jats:italic> with the ability to transform SO<jats:sub>4</jats:sub><jats:sup>2−</jats:sup> into S<jats:sup>2−</jats:sup> increased significantly in all treatments, except for CK. There was a strong correlation between environmental factors (pH, Eh, SO<jats:sub>4</jats:sub><jats:sup>2−</jats:sup>, Pb, and Zn) and bacterial community structure. Furthermore, functional prediction analysis revealed that the SRB inoculation treatments significantly increased the abundance of sulfate respiration, sulfite respiration, and nitrogen fixation, while decreasing the abundance of manganese oxidation, dark hydrogen oxidation, and denitrification. This provides good evidence for us to understand the difference in removal efficiency, bacterial community structure, and function by different remediation measures that help select a more efficient and sustainable method to remediate contaminants in the REM soil.</jats:p>

Kartikey K. Gupta, Deepa Devi

Remediation Journal • 2020

<jats:title>Abstract</jats:title><jats:p>Biodegradation is an attractive approach for the elimination of synthetic polymers, pervasively accumulated in natural environments and generating ecological problems. The present work investigated the degradation of low‐density polyethylene (PE) by three <jats:italic>Bacillus</jats:italic> sp., that is, ISJ36, ISJ38, and ISJ40. The degree of biodegradation was assessed by measuring hydrophobicity, viability, and total protein content of bacterial biofilm attached to the PE surface. Although all three bacterial strains were able to establish an active biofilm community on the PE surface, ISJ40 showed better affinity toward PE degradation than the other two. Bacterial colonization and physical changes on the PE surface were visualized by scanning electron microscopy. Fourier transform infrared spectroscopy analysis revealed alteration in the intensities of functional groups along with an increase in the carbonyl bond indexes. The study results suggest that the <jats:italic>Bacillus</jats:italic> strain ISJ40 can be used as a potential degrader for the eco‐friendly treatment of PE waste.</jats:p>

Longfei Xia

IOP Conference Series: Earth and Environmental Science • 2019

Leakage accidents occur frequently during the process of oil exploitation, storage and transportation. Effective management of the soil contaminated by it has become the focus of social attention. This paper introduces the oil pollution problem and physical, chemical and biological treatment methods. It focuses on the classification and application status of microbial remediation technology, and discusses the key factors that restrict bioremediation effects such as degrading microbial screening and colonization, and improving the bioavailability of petroleum hydrocarbons.

Ying Wu, P. Feng, Rong Li et al.

• 2019

In recent years, antibiotics have been widely used in animal husbandry, aquaculture and the medication in China. Many antibiotics are discharged into the environment, resulting in dramatic increase of antibiotic residues in domestic water and soil. Residues of different antibiotics in the environment change the microbial structure, which is extremely harmful to the ecological environment and humans. Therefore, remediation of antibiotic contamination is significantly important. Studies have shown that some microorganisms can degrade and utilize antibiotics, and thus have good application prospects on bioremediation of antibiotic contamination. However, little is known about the microbial degradation mechanism of antibiotics. This article summarizes the removal of antibiotics by antibiotic-degrading strains and bacterial flora in recent ten years, and the methods of using microbial flora to treat antibiotic residues. The future prospect of using microbial remediation to reduce antibiotic residues in the environment has also been discussed.

Haixuan Zhou, Xiurong Gao, Suhang Wang et al.

International Journal of Environmental Research and Public Health • 2023

Microbial biodegradation is considered as one of the most effective strategies for the remediation of soil contaminated with polycyclic aromatic hydrocarbons (PAHs). To improve the degradation efficiency of PAHs, PAH-degrading consortia combined with strengthening remediation strategies was used in this study. The PAH biodegrading performance of seven bacterial consortia constructed by different ratios of Mycobacterium gilvum MI, Mycobacterium sp. ZL7 and Rhodococcus rhodochrous Q3 was evaluated in an aqueous system containing phenanthrene, pyrene, benzo[a]pyrene and benzo[b]fluoranthene. Bacterial consortium H6 (Q3:ZL7:MI = 1:2:2) performed a high degrading efficiency of 59% in 8 days. The H6 was subsequently screened to explore its potential ability and performance to degrade aged PAHs in soils from a coking plant and the effects of strengthening strategies on the aged PAH degradation, including the addition of glucose or sodium dodecyl benzene sulfonate (SDBS) individually or as a mixture along immobilization of the inoculant on biochar. The highest degradation efficiencies, which were 15% and 60% for low-molecular-weight (LMW) PAHs and high-molecular-weight (HMW) PAHs, respectively, were observed in the treatment using immobilized microbial consortium H6 combined with the addition of glucose and SDBS after 24 days incubation. This study provides new insights and guidance for future remediation of aged PAH contaminated soils.

Dan Li, X. You

Soil and Sediment Contamination: An International Journal • 2020

ABSTRACT At present, plant–microbial remediation of soil petroleum pollution has been widely used, but the study of using models to predict remediation effect and find optimal remediation conditions is still very lacking. In this paper, on the basis of the numerical model of previous research, the effects of Suaeda salsa–microbial remediation technique on soil petroleum hydrocarbon pollution were simulated under different soil initial pollutant concentration, soil moisture content and tillage depth. The spatial and temporal degradation of petroleum hydrocarbons and the corresponding degradation rate were studied. The results showed that under different remediation conditions, the degradation rate of microbes, plant and plant–microbial of petroleum hydrocarbon is in the range of 12.70%–24.70%, 4.14%–54.58% and 29.32%–67.28% in 180 days, respectively. It was found that the degradation rate of petroleum hydrocarbons was significantly affected by soil initial pollutant concentration, soil moisture content and tillage depth. The optimal application conditions of S. salsa–microbial remediation technology were found for the remediation of soil petroleum hydrocarbon pollution.

Yu-Bin Jin, Yaning Luan, Yang Ning et al.

Applied Sciences • 2018

The use of microbes to change the concentration of heavy metals in soil and improve the ability of plants to deal with elevated metals concentrations has significant economic and ecological benefits. This paper reviews the origins and toxic effects of heavy metal pollution in soil, and describes the heavy metal accumulation mechanisms of microbes, and compares their different bioconcentration abilities. Biosorption, which depends on the special structure of the cell wall, is found to be the primary mechanism. Furthermore, Escherichia coli are found to adsorb more heavy metals than other species. Factors influencing microbial treatment of wastewater and soil containing heavy metals include temperature, pH, and different substrates. Finally, problems in the application of microbial treatment of heavy metal contamination are considered, and possible directions for future research are discussed.

K. Agrawal, Tannu Ruhil, V.K. Gupta et al.

Critical Reviews in Biotechnology • 2023

Abstract Rapidly increasing heavy metal waste has adversely affected the environment and the Earth’s health. The lack of appropriate remediation technologies has worsened the issue globally, especially in developing countries. Heavy-metals contaminants have severely impacted the environment and led to devastating conditions owing to their abundance and reactivity. As they are nondegradable, the potential risk increases even at a low concentration. However, heavy-metal remediation has increased with the up-gradation of technologies and integration of new approaches. Also, of all the treatment methodologies, microbial-assisted multifaceted approach for ameliorating heavy metals is a promising strategy for propagating the idea of a green and sustainable environment with minimal waste aggregation. Microbial remediation combined with different biotechniques could aid in unraveling new methods for eradicating heavy metals. Thus, the present review focuses on various microbial remediation approaches and their affecting factors, enabling recapitulation of the interplay between heavy-metals ions and microorganisms. Additionally, heavy-metals remediation mechanisms adapted by microorganisms, the role of genetically modified (GM) microorganisms, life cycle assessment (LCA), techno-economic assessment (TEA) limitations, and prospects of microbial-assisted amelioration of heavy-metals have been elaborated in the current review with focus toward “sustainable and greener future.” GRAPHICAL ABSTRACT

A. K. Wani, N. Akhtar, Nafiaah Naqash et al.

Environmental Science and Pollution Research • 2023

Microplastics (MPs) are ubiquitous pollutants persisting almost everywhere in the environment. With the increase in anthropogenic activities, MP accumulation is increasing enormously in aquatic, marine, and terrestrial ecosystems. Owing to the slow degradation of plastics, MPs show an increased biomagnification probability of persistent, bioaccumulative, and toxic substances thereby creating a threat to environmental biota. Thus, remediation of MP-pollutants requires efficient strategies to circumvent the mobilization of contaminants leaching into the water, soil, and ultimately to human beings. Over the years, several microorganisms have been characterized by the potential to degrade different plastic polymers through enzymatic actions. Metagenomics (MGs) is an effective way to discover novel microbial communities and access their functional genetics for the exploration and characterization of plastic-degrading microbial consortia and enzymes. MGs in combination with metatranscriptomics and metabolomics approaches are a powerful tool to identify and select remediation-efficient microbes in situ. Advancement in bioinformatics and sequencing tools allows rapid screening, mining, and prediction of genes that are capable of polymer degradation. This review comprehensively summarizes the growing threat of microplastics around the world and highlights the role of MGs and computational biology in building effective response strategies for MP remediation.

Ying Zhang, Shuai Liu, Lili Niu et al.

Biochar • 2023

Immobilized microbial technology has been widely used in wastewater treatment, but it has been used less frequently for soil remediation, particularly in sites that are co-contaminated with organic compounds and heavy metals. In addition, there is limited knowledge on the efficiency of remediation and microbial preferences to colonize the immobilized carriers. In this study, biochar immobilized with Sphingobium abikonense was introduced to remediate soils that were co-contaminated with phenanthrene (PHE) and copper (Cu), and the mechanisms of microbial assemblage were investigated. The immobilized microbial biochar maintained a degradation rate of more than 96% in both the first (0–6 d) and second (6–12 d) contamination periods. The addition of biochar increased the proportion of Cu bound to organic matter, and Fe–Mn oxide bound Cu in the soil. In addition, both Cu and PHE could be adsorbed into biochar pellets in the presence or absence of immobilized S. abikonense . The presence of biochar significantly increased the abundance of bacteria, such as Luteibacter , Bordetella and Dyella , that could degrade organic matter and tolerate heavy metals. Notably, the biochar could specifically select host microbes from the soil for colonization, while the presence of S. abikonense affected this preference. The autonomous selection facilitates the degradation of PHE and/or the immobilization of Cu in the soil. These results provide a green approach to efficiently and sustainably remediate soil co-contaminated with PHE and Cu and highlight the importance of microbial preference colonized in immobilized carriers. Graphical Abstract Biochar immobilized with S. abikonense could degrade PHE efficiently and sustainably. Pellets of biochar immobilized with S. abikonense adsorbed more Cu on its surface. Biochar had a selective preference for its colonized microbial communities.

Sheng-Yuan Wang, Longyang Fang, Malcom Frimpong Dapaah et al.

Sustainability • 2023

Biomineralization processes utilizing microbial-induced carbonate precipitation (MICP) have recently shown promise as an effective approach for remediating heavy metal contamination. This article offers a comprehensive review of the latest research on MICP-mediated heavy metal remediation, with a focus on the characteristics of heavy metals in the treated environment, such as copper, cadmium, lead, nickel, zinc, chromium, and mixed heavy metals. The review summarizes experimental results from various heavy metals treated by MICP, including the enrichment and screening of new urease-positive bacteria, the mineral structure of different heavy metal precipitates, and the efficiency of the MICP technology. Recent advancements in the MICP technology regarding heavy metal removal, long-term stability, and practical applications are also discussed. Additionally, the limitations of the technique and existing solutions are reviewed. In addition, it provides insights on future directions for further research and development of the MICP approach for heavy metal remediation, in order to optimize the technique and improve its efficiency. Overall, the review highlights the potential of MICP as a viable method for heavy metal remediation, offering promising results for the removal of a variety of heavy metal contaminants from contaminated environments.

M. Tripathi, Pankaj Singh, Ranjan Singh et al.

Frontiers in Microbiology • 2023

Toxic wastes like heavy metals and dyes are released into the environment as a direct result of industrialization and technological progress. The biosorption of contaminants utilizes a variety of biomaterials. Biosorbents can adsorb toxic pollutants on their surface through various mechanisms like complexation, precipitation, etc. The quantity of sorption sites that are accessible on the surface of the biosorbent affects its effectiveness. Biosorption’s low cost, high efficiency, lack of nutrient requirements, and ability to regenerate the biosorbent are its main advantages over other treatment methods. Optimization of environmental conditions like temperature, pH, nutrient availability, and other factors is a prerequisite to achieving optimal biosorbent performance. Recent strategies include nanomaterials, genetic engineering, and biofilm-based remediation for various types of pollutants. The removal of hazardous dyes and heavy metals from wastewater using biosorbents is a strategy that is both efficient and sustainable. This review provides a perspective on the existing literature and brings it up-to-date by including the latest research and findings in the field.

Usman Zulfiqar, F. Haider, Muhammad Faisal Maqsood et al.

Plants • 2023

Soil contamination with cadmium (Cd) is a severe concern for the developing world due to its non-biodegradability and significant potential to damage the ecosystem and associated services. Industries such as mining, manufacturing, building, etc., rapidly produce a substantial amount of Cd, posing environmental risks. Cd toxicity in crop plants decreases nutrient and water uptake and translocation, increases oxidative damage, interferes with plant metabolism and inhibits plant morphology and physiology. However, various conventional physicochemical approaches are available to remove Cd from the soil, including chemical reduction, immobilization, stabilization and electro-remediation. Nevertheless, these processes are costly and unfriendly to the environment because they require much energy, skilled labor and hazardous chemicals. In contrasting, contaminated soils can be restored by using bioremediation techniques, which use plants alone and in association with different beneficial microbes as cutting-edge approaches. This review covers the bioremediation of soils contaminated with Cd in various new ways. The bioremediation capability of bacteria and fungi alone and in combination with plants are studied and analyzed. Microbes, including bacteria, fungi and algae, are reported to have a high tolerance for metals, having a 98% bioremediation capability. The internal structure of microorganisms, their cell surface characteristics and the surrounding environmental circumstances are all discussed concerning how microbes detoxify metals. Moreover, issues affecting the effectiveness of bioremediation are explored, along with potential difficulties, solutions and prospects.

S. Jaiswal, Pratyoosh Shukla

Frontiers in Microbiology • 2020

Continuous contamination of the environment with xenobiotics and related recalcitrant compounds has emerged as a serious pollution threat. Bioremediation is the key to eliminating persistent contaminants from the environment. Traditional bioremediation processes show limitations, therefore it is necessary to discover new bioremediation technologies for better results. In this review we provide an outlook of alternative strategies for bioremediation via synthetic biology, including exploring the prerequisites for analysis of research data for developing synthetic biological models of microbial bioremediation. Moreover, cell coordination in synthetic microbial community, cell signaling, and quorum sensing as engineered for enhanced bioremediation strategies are described, along with promising gene editing tools for obtaining the host with target gene sequences responsible for the degradation of recalcitrant compounds. The synthetic genetic circuit and two-component regulatory system (TCRS)-based microbial biosensors for detection and bioremediation are also briefly explained. These developments are expected to increase the efficiency of bioremediation strategies for best results.

Lei Shi, Zhongzheng Liu, Liangyan Yang et al.

Annals of Microbiology • 2022

Purpose This study investigates the feasibility of bio-enhanced microbial remediation of petroleum-contaminated soil, and analyzes the effect of different plant wastes as exogenous stimulants on microbial remediation of petroleum-contaminated soil and the effect on soil microbial community structure, in order to guide the remediation of soil in long-term petroleum-contaminated areas with nutrient-poor soils. Methods The study was conducted in a representative oil extraction area in the Loess Hills, a typical ecologically fragile area in China. Through indoor simulated addition tests, combined with the determination of soil chemical and microbiological properties, the degradation efficiency of petroleum pollutants and the response characteristics of soil microbial community structure to the addition of different plant wastes in the area were comprehensively analyzed to obtain the optimal exogenous additive and explore the strengthening mechanism of plant wastes on microbial remediation of petroleum-contaminated soil. Results Compared with the naturally decaying petroleum-contaminated soil, the addition of plant waste increased the degradation rate of petroleum pollutants, that is, it strengthened the degradation power of indigenous degrading bacteria on petroleum pollutants, among which the highest degradation rate of petroleum pollutants was achieved when the exogenous additive was soybean straw; compared with the naturally decaying petroleum-contaminated soil, the addition of soybean straw and dead and fallen leaves of lemon mallow made the microbial species in the contaminated soil significantly reduced and the main dominant flora changed, but the flora capable of degrading petroleum pollutants increased significantly; the addition of exogenous nutrients had significant effects on soil microbial diversity and community structure. Conclusions Soybean straw can be added to the contaminated soil as the optimal exogenous organic nutrient system, which improves the physicochemical properties of the soil and gives a good living environment for indigenous microorganisms with the function of degrading petroleum pollutants, thus activating the indigenous degrading bacteria in the petroleum-contaminated soil and accelerating their growth and proliferation and new city metabolic activities, laying a foundation for further obtaining efficient, environmentally friendly and low-cost microbial enhanced remediation technology solutions. The foundation for further acquisition of efficient, environmentally friendly, and low-cost microbial-enhanced remediation technology solutions. It is important for improving soil remediation in areas with long-term oil contamination and nutrient-poor soils.

Shipei Wang, Ting Liu, Xiaocun Xiao et al.

Journal of Leather Science and Engineering • 2021

Abstract In recent years, microbiological treatment to remediate contamination by heavy metals has aroused public attention as such pollution has seriously threatens ecosystems and human health and impedes sustainable development. However, the aspect of actual industrial wastewater and solid waste remediation by microorganisms is not explored sufficiently. And what we focus on is technical field of microbial remediation. Therefore, in this review, we discuss and summarize heavy metal treatment via microbiological approaches in different media, including wastewater, solid waste from industrial factories and polluted sites. We also clarify the technical applicability from the perspective of biosorption, bioleaching, biominerization, etc. In particular, the exploration of the combination of microbiological approaches with chemical methods or phytoextraction are scrutinized in this review relative to real waste heavy metal remediation. Furthermore, we highlight the importance of hyperaccumulator endophytes. Graphical abstract

Isma Gul, Muhammad Adil, Fenglin Lv et al.

Frontiers in Microbiology • 2024

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

P. Sahoo, Sikha Singh, P. Rout et al.

Biotechnology and Genetic Engineering Reviews • 2022

ABSTRACT A wide range of plastic debris dumped into the ocean has recently gained concern of the marine ecosystems. Discarded and abandoned fishing nets, also known as ghost nets, are lost in the marine water and has no commercial significance. Additionally these fishing gear left out in the aquatic environment pose a severe risk to marine environment. Fishing nets, made up of synthetic plastic materials, are a major source of marine pollutants and act as a vector for transporting other toxic chemical pollutants. Approximately 10% of total marine plastic pollutants come from commercial fishing nets, and each year up to 1 million tons of fishing gear are discarded into the marine ecosystem. It can be estimated that by 2050 the amount will be doubled, adding 15–20 million metric tons of discarded lost fishing gears into ocean. The gradual and increased deposition of plastic pollutants in aquatic habitat also affects the whole food chain. Recently, microbial degradation of marine plastics has focussed the eyes of researchers and a lot of investigations on potential microbial degraders are under process. Microorganisms have developed the ability to grow under plastic stress condition and adapt to alter metabolic pathways by which they can directly feed upon marine plastic pollutants as sole carbon source. The present review compiles information on marine plastic pollution from discarded and abandoned fishing nets, their effect on aquatic ecosystems, marine animals and food chain and discusses microbial remediation strategies to control this pollution, especially and their implications in the marine ecosystems.

Najeebul Tarfeen, Khair Ul Nisa, B. Hamid et al.

Processes • 2022

Heavy metal and pesticide pollution have become an inevitable part of the modern industrialized environment that find their way into all ecosystems. Because of their persistent nature, recalcitrance, high toxicity and biological enrichment, metal and pesticide pollution has threatened the stability of the environment as well as the health of living beings. Due to the environmental persistence of heavy metals and pesticides, they get accumulated in the environs and consequently lead to food chain contamination. Therefore, remediation of heavy metals and pesticide contaminations needs to be addressed as a high priority. Various physico-chemical approaches have been employed for this purpose, but they have significant drawbacks such as high expenses, high labor, alteration in soil properties, disruption of native soil microflora and generation of toxic by-products. Researchers worldwide are focusing on bioremediation strategies to overcome this multifaceted problem, i.e., the removal, immobilization and detoxification of pesticides and heavy metals, in the most efficient and cost-effective ways. For a period of millions of evolutionary years, microorganisms have become resistant to intoxicants and have developed the capability to remediate heavy metal ions and pesticides, and as a result, they have helped in the restoration of the natural state of degraded environs with long term environmental benefits. Keeping in view the environmental and health concerns imposed by heavy metals and pesticides in our society, we aimed to present a generalized picture of the bioremediation capacity of microorganisms. We explore the use of bacteria, fungi, algae and genetically engineered microbes for the remediation of both metals and pesticides. This review summarizes the major detoxification pathways and bioremediation technologies; in addition to that, a brief account is given of molecular approaches such as systemic biology, gene editing and omics that have enhanced the bioremediation process and widened its microbiological techniques toward the remediation of heavy metals and pesticides.

V. Rajput, S. Kumari, T. Minkina et al.

Air, Soil and Water Research • 2023

The emergence of polycyclic aromatic hydrocarbons (PAHs) from a variety of natural and anthropogenic sources, such as coal gasification and liquefaction plants, coke and aluminum production, catalytic cracking towers, and motor vehicle exhaust, among others, results in significant soil pollution, and a threat to human health, igniting a surge of interest in advanced research. Even though the cleanup of PAHs-contaminated areas received a great consideration. In the last decade, nanotechnology has exploded in popularity as a result of several unique properties of nanomaterials, and remediation is no exception. Thus, nano-enhanced bioremediation reported to act as a viable and effective strategy for PAHs remediation. Further, the integration of nano-enabled materials with microorganisms emerged as a promising biodegradation approach for PAHs remediation. As a result, the focus of this mini review is on depicting the possible roles of various nanomaterials in decontaminating PAHs as a green strategy by boosting the efficacy of microbial functionality, and mechanism of nanoparticles-microbes interaction in PAHs degradation. The future perspective of nano-enhanced microbial remediation of PAHs in realistic environments are also discussed.

Tingting Wang, Jiaxin Xu, Jian Chen et al.

Plants • 2024

More food is needed to meet the demand of the global population, which is growing continuously. Chemical fertilizers have been used for a long time to increase crop yields, and may have negative effect on human health and the agricultural environment. In order to make ongoing agricultural development more sustainable, the use of chemical fertilizers will likely have to be reduced. Microbial fertilizer is a kind of nutrient-rich and environmentally friendly biological fertilizer made from plant growth-promoting bacteria (PGPR). Microbial fertilizers can regulate soil nutrient dynamics and promote soil nutrient cycling by improving soil microbial community changes. This process helps restore the soil ecosystem, which in turn promotes nutrient uptake, regulates crop growth, and enhances crop resistance to biotic and abiotic stresses. This paper reviews the classification of microbial fertilizers and their function in regulating crop growth, nitrogen fixation, phosphorus, potassium solubilization, and the production of phytohormones. We also summarize the role of PGPR in helping crops against biotic and abiotic stresses. Finally, we discuss the function and the mechanism of applying microbial fertilizers in soil remediation. This review helps us understand the research progress of microbial fertilizer and provides new perspectives regarding the future development of microbial agent in sustainable agriculture.

Qidong Yin, Kai-Ze He, Gavin Collins et al.

npj Clean Water • 2024

Microbial metabolism upholds a fundamental role in the sustainability of water ecosystems. However, how microorganisms surviving in low-concentration substrate water environments, including the existence of emerging compounds of interest, remains unclear. In this review, microbial strategies for concentrating, utilizing, and metabolizing of low concentration substrates were summarized. Microorganisms develop substrate-concentrating strategies at both the cell and aggregate levels in substrate-limited settings. Following, microbial uptake and transport of low-concentration substrates are facilitated by adjusting physiological characteristics and shifting substrate affinities. Finally, metabolic pathways, such as mixed-substrate utilization, syntrophic metabolism, dynamic response to nutrient variation, and population density-based mechanisms allow microorganisms to efficiently utilize low-concentration substrates and to adapt to challenging oligotrophic environments. All these microbial strategies will underpin devising new approaches to tackle environmental challenges and drive the sustainability of water ecosystems, particularly in managing low-concentration contaminants (i.e., micropollutants).

S. Malik, Dharmender Kumar

Biotechnology and Genetic Engineering Reviews • 2023

ABSTRACT Nanomaterials (NMs) have diverse applications in various sectors, such as decontaminating heavy metals from drinking water, wastewater, and soil. Their degradation efficiency can be enhanced through the application of microbes. As microbial strain releases enzymes, which leads to the degradation of HMs. Therefore, nanotechnology and microbial-assisted remediation-based methods help us develop a remediation process with practical utility, speed, and less environmental toxicity. This review focuses on the success achieved for the bioremediation of heavy metals by nanoparticles and microbial strains and in their integrated approach. Still, the use of NMs and heavy metals (HMs) can negatively affect the health of living organisms. This review describes various aspects of the bioremediation of heavy materials using microbial nanotechnology. Their safe and specific use supported by bio-based technology paves the way for their better remediation. We discuss the utility of nanomaterials for removing heavy metals from wastewater, toxicity studies and issues to the environment with their practical implications. Nanomaterial assisted heavy metal degradation coupled with microbial technology and disposal issues are described along with detection methods. Environmental impact of nanomaterials is also discussed based on the recent work conducted by the researchers. Therefore, this review opens new avenues for future research with an impact on the environment and toxicity issues. Also, applying new biotechnological tools will help us develop better heavy metal degradation routes.

Shiva Aliyari Rad, K. Nobaharan, N. Pashapoor et al.

Sustainability • 2023

The pollution of soil by heavy metals and organic pollutants has become a significant issue in recent decades. For the last few years, nanobiotechnology has been used to bio-remediate or reclaim soil contaminated with organic and inorganic pollutants. The removal of pollutants from industrial wastes is a major challenge. The utilization of nanomaterials is gaining popularity, which might be accredited to their enhanced physical, chemical, and mechanical qualities. The development of advanced nanobiotechnological techniques involving the use of nanomaterials for the reclamation of polluted soils has indicated promising results and future hope for sustainable agriculture. By manufacturing environment-friendly nanomaterials, the industrial expenditure on decreasing the load of pollution might be reduced. A potential emerging domain of nanotechnology for eco-friendly production and cost reduction is “green biotechnology”, alongside the utilization of microorganisms in nanoparticle synthesis.

Xuehao Zheng, B. T. Oba, Chenbo Shen et al.

Frontiers in Microbiology • 2023

Introduction The accumulation of petroleum hydrocarbons (PHs) in the soil can reduce soil porosity, hinder plant growth, and have a serious negative impact on soil ecology. Previously, we developed PH-degrading bacteria and discovered that the interaction between microorganisms may be more important in the degradation of PHs than the ability of exogenous-degrading bacteria. Nevertheless, the role of microbial ecological processes in the remediation process is frequently overlooked. Methods This study established six different surfactant-enhanced microbial remediation treatments on PH-contaminated soil using a pot experiment. After 30 days, the PHs removal rate was calculated; the bacterial community assembly process was also determined using the R language program, and the assembly process and the PHs removal rate were correlated. Results and discussion The rhamnolipid-enhanced Bacillus methylotrophicus remediation achieved the highest PHs removal rate, and the bacterial community assembly process was impacted by deterministic factors, whereas the bacterial community assembly process in other treatments with low removal rates was affected by stochastic factors. When compared to the stochastic assembly process and the PHs removal rate, the deterministic assembly process and the PHs removal rate were found to have a significant positive correlation, indicating that the deterministic assembly process of bacterial communities may mediate the efficient removal of PHs. Therefore, this study recommends that when using microorganisms to remediate contaminated soil, care should be taken to avoid strong soil disturbance because directional regulation of bacterial ecological functions can also contribute to efficient removal of pollutants.

Haiying Tang, Guohong Xiang, Wen Xiao et al.

Frontiers in Plant Science • 2024

Heavy metal pollution has become a serious concern across the globe due to their persistent nature, higher toxicity, and recalcitrance. These toxic metals threaten the stability of the environment and the health of all living beings. Heavy metals also enter the human food chain by eating contaminated foods and cause toxic effects on human health. Thus, remediation of HMs polluted soils is mandatory and it needs to be addressed at higher priority. The use of microbes is considered as a promising approach to combat the adverse impacts of HMs. Microbes aided in the restoration of deteriorated environments to their natural condition, with long-term environmental effects. Microbial remediation prevents the leaching and mobilization of HMs and they also make the extraction of HMs simple. Therefore, in this context recent technological advancement allowed to use of bioremediation as an imperative approach to remediate polluted soils. Microbes use different mechanisms including bio-sorption, bioaccumulation, bioleaching, bio-transformation, bio-volatilization and bio-mineralization to mitigate toxic the effects of HMs. Thus, keeping in the view toxic HMs here in this review explores the role of bacteria, fungi and algae in bioremediation of polluted soils. This review also discusses the various approaches that can be used to improve the efficiency of microbes to remediate HMs polluted soils. It also highlights different research gaps that must be solved in future study programs to improve bioremediation efficency.

Shuai Zhao, Xue-Tao Yuan, Xiao-Hong Wang et al.

Sustainability • 2024

Microbial remediation has become a prominent focus in soil pollution control due to its environmental friendliness, cost-effectiveness, and high efficiency. The effectiveness of microbial remediation is rooted in the interactions between microbial metabolic activities and the soil environment. Various microorganisms employ distinct mechanisms for pollutant treatment, including surface adsorption, intracellular accumulation, and biomineralization. Using the Web of Science Core Collection database, tools such as CiteSpace 6.1.R6, VOSviewer 1.6.20, and HistCite Pro were employed to conduct a quantitative analysis of several key aspects: the volume and thematic distribution of research papers on microbial remediation of soils, the cooperative networks between countries and institutions, the leading journals, major research hotspots, and emerging trends. The analysis reveals that utilizing microbial regulatory mechanisms and functions to remediate inorganic pollutants, such as heavy metals, and organic pollutants, such as PAHs, is becoming a significant frontier in future research. This study provides a valuable reference for scholars aiming to understand the current status of microbial research in soil remediation, both domestically and internationally. It also offers guidance for developing efficient, sustainable, and safe remediation strategies while identifying directions for future innovative research. The specific results are as follows: (1) China, the USA, India, and other countries have a high frequency of citations in this field, and the research is more in-depth. (2) More and more attention has been paid to the use of microbial remediation of contaminated soil in the world, mainly in Environmental Sciences. (3) Major publications include Chemosphere, Journal of Hazardous Materials, and Science of The Total Environment. In the key literature, the use of microorganisms to restore the soil environment and the combination of microorganisms and plants to repair soil contaminated by heavy metals occupy a high proportion. (4) The key areas of focus include the application of microorganisms in soil inorganic pollution remediation, the application of microorganisms in remediation of soil organic pollution (crude oil and polycyclic aromatic hydrocarbons (PAHs)), and the contribution of microorganisms to soil pollutant degradation and toxicity assessment systems. The research and development of combined microbial remediation technology is the current research hotspot in the field of soil remediation, focusing on the symbiosis between mycorrhizal fungi and plant roots, the enhancement in the ability of microorganisms to absorb and degrade pollutants and their tolerance, and the interaction mechanism between indigenous microorganisms and plants.

Wu‐Juan Sun, Qian Li, Bo-Yun Luo et al.

Environmental Geochemistry and Health • 2024

Soil contamination by petroleum, including crude oil from various sources, is increasingly becoming a pressing global environmental concern, necessitating the exploration of innovative and sustainable remediation strategies. The present field-scale study developed a simple, cost-effective microbial remediation process for treating petroleum-contaminated soil. The soil treatment involves adding microbial activators to stimulate indigenous petroleum-degrading microorganisms, thereby enhancing the total petroleum hydrocarbons (TPH) degradation rate. The formulated microbial activator provided a growth-enhancing complex of nitrogen and phosphorus, trace elements, growth factors, biosurfactants, and soil pH regulators. The field trials, involving two 500 m3 soil samples with the initial TPH content of 5.01% and 2.15%, were reduced to 0.41% and 0.02% in 50 days, respectively, reaching the national standard for cultivated land category II. The treatment period was notably shorter than the commonly used composting and bioaugmentation methods (typically from 8 to 12 weeks). The results indicated that the activator could stimulate the functional microorganisms in the soil and reduce the phytotoxicity of the contaminated soil. After 40 days of treatment, the germination rate of rye seeds increased from 20 to 90%, indicating that the microbial activator could be effectively used for rapid on-site remediation of oil-contaminated soils.

Jatinder Singh Randhawa

Bulletin of the National Research Centre • 0

<jats:title>Abstract</jats:title><jats:sec><jats:title>Background</jats:title><jats:p>Neonicotinoids are a group of synthetic insecticides that are highly effective and have a wide range of insecticidal activities. This group includes acetamiprid, dinotefuran, clothianidin, imidacloprid, sulfoxaflor, nitenpyram, thiamethoxam, and thiacloprid. They are extensively used worldwide, both in rural and urban environments. However, the widespread use of neonicotinoids has led to their accumulation and biomagnification in the environment due to their long half-life. This has resulted in the emergence of toxicological and hazardous pollutants, posing significant risks to humans and non-target animals. Neonicotinoids are a type of insecticides that bind to neuronal nicotinic acetylcholine receptors (nAChRs). This mechanism allows them to effectively activate insect nAChRs while having minimal impact on vertebrate nAChRs. This reduces the risk of toxicity and makes them safer for non-target species. However, the presence of neonicotinoids in the environment can still increase the risk of toxicity and exposure. Although they have low affinity for mammalian nAChRs, concerns arise due to the abundance, diversity, and widespread presence of these receptors, as well as their various functions. These factors raise concerns about the potential impact of these pesticides on unintended species. Therefore, it is crucial to remove neonicotinoids from the environment in a sustainable and methodical manner.</jats:p></jats:sec><jats:sec><jats:title>Main body of the abstract</jats:title><jats:p>Various techniques can be employed to eliminate neonicotinoid residues in soil and aquatic habitats. These techniques include physiochemical remediation methods such as advanced oxidation processes, adsorption, oxidation, Fenton technology, photocatalysis, and activated persulfate-based oxidation. Additionally, microbial remediation techniques involving bacteria, fungi, and microalgae can also be utilized. This review aims to focus on the scientific foundation, advancements, and key topics related to microbial remediation technologies for neonicotinoids. Proper implementation of bioremediation techniques can significantly reduce the harmful effects of neonicotinoids on the environment and human health.</jats:p></jats:sec><jats:sec><jats:title>Short conclusion</jats:title><jats:p>The main focus of this review is the new studies on the bioremediation of neonicotinoids by bacteria, fungi, and microalgae, and the role of their enzymes. This topic is gaining importance as pesticide bioremediation techniques become increasingly significant.</jats:p></jats:sec>

Narcís Pous, Maria Dolors Balaguer, Jesús Colprim et al.

Microbial Biotechnology • 2018

<jats:title>Summary</jats:title><jats:p>Groundwater pollution is a serious worldwide concern. Aromatic compounds, chlorinated hydrocarbons, metals and nutrients among others can be widely found in different aquifers all over the world. However, there is a lack of sustainable technologies able to treat these kinds of compounds. Microbial electro‐remediation, by the means of microbial electrochemical technologies (<jats:styled-content style="fixed-case">MET</jats:styled-content>), can become a promising alternative in the near future. <jats:styled-content style="fixed-case">MET</jats:styled-content> can be applied for groundwater treatment <jats:italic>in situ</jats:italic> or <jats:italic>ex situ</jats:italic>, as well as for monitoring the chemical state or the microbiological activity. This document reviews the current knowledge achieved on microbial electro‐remediation of groundwater and its applications.</jats:p>

Umair Riaz, Laila Shahzad, Wajiha Anum et al.

Advances in Environmental Engineering and Green Technologies • 2021

<jats:p>Beneficial microbes are used as the best alternative against the synthetic fertilizers and pesticides. The beneficial microbes not only help with plant growth, nutrition uptake, nitrogen fixation, but also help in acquiring the ions, not freely available to plants to uptake; these microbes also guard the plants by secreting toxic chemicals by inducing defense systems against pathogens. These microbes can provide best choice to look forward to sustainable agriculture and sustainable ecosystem. The addition of soil inoculants in the form of microorganisms or bio stimulants promise more environmentally friendly approaches for augmenting crop yields. The crop becomes less reliant on chemical fungicides and herbicides as many strains of microorganism have abilities of controlling pests. In this chapter, the interaction of beneficial plant bacteria, bio stimulants, effects on native microbial communities, and bacteria influencing economically important crops are discussed. </jats:p>

Mathew P Watts, John W Moreau

Microbiology Australia • 2018

<jats:p>Thiocyanate (SCN–) forms in the reaction between cyanide (CN–) and reduced sulfur species, e.g. in gold ore processing and coal-coking wastewater streams, where it is present at millimolar (mM) concentrations1. Thiocyanate is also present naturally at nM to µM concentrations in uncontaminated aquatic environments2. Although less toxic than its precursor CN–, SCN– can harm plants and animals at higher concentrations3, and thus needs to be removed from wastewater streams prior to disposal or reuse. Fortunately, SCN– can be biodegraded by microorganisms as a supply of reduced sulfur and nitrogen for energy sources, in addition to nutrients for growth4. Research into how we can best harness the ability of microbes to degrade SCN– may offer newer, more cost-effective and environmentally sustainable treatment solutions5. By studying biodegradation pathways of SCN– in laboratory and field treatment bioreactor systems, we can also gain fundamental insights into connections across the natural biogeochemical cycles of carbon, sulfur and nitrogen6.</jats:p>

Leena Merlin Biju, Veena Gayathri Krishnaswamy

Advances in Environmental Engineering and Green Technologies • 2021

<jats:p>Industrialization led to the release of synthetic and toxic compounds. Partial or improper treatment increases environmental pollution. Conventional methods possess more disadvantages, such as increased duration of degradation and release of secondary pollutants. The drawbacks paved the way for the significant bioremediation perspective. The ubiquitous nature of microbes enables it to utilize toxic compounds, which attracted the focus of treatment towards the biological and eco-friendly methods. The recent decade has shown interest in the application of indigenous microbes in the polluted environment. Apart from the microbial application, phytoremediation is an emerging tool for treating soil contaminated with hazardous pollutants. Technological advancement in biotechnology ensures a safe and healthy environment for a better future. </jats:p>

Asha Laxman Giriyan, Vikrant B. Berde, Elroy J. Pereira et al.

Advances in Environmental Engineering and Green Technologies • 2021

<jats:p>Heavy metals are found naturally. Anthropogenic activities and rapid industrialization have led to their unprecedented release into the environment. Being non-biodegradable in nature, they persist in the environment. Prolonged exposure and accumulation of these metals poses a serious threat to the ecosystem. Conventional treatment of contaminated material whether soil or water involves expensive chemical or physical methods which are arduous, energy demanding, and carry the risk of secondary contamination. It is thus necessary to adopt a sustainable remediation process to mitigate this problem. Biological remediation processes are preferable as they are environmentally safe, techno-economically feasible, and do not generate toxic byproducts. Microbial bioremediation is particularly attractive as it allows remediation processes by tapping naturally occurring catabolic capacities to transform, accumulate, and adsorb metals for detoxification. It is a comparatively low-cost technology. Therefore, microbial bioremediation is promising as an alternative to physico-chemical methods. </jats:p>

Lirong Zhong, M. R. Islam

SPE Annual Technical Conference and Exhibition • 1995

<jats:title>Abstract</jats:title> <jats:p>Microbial mineral precipitation occurs constantly over the geological time. This process induces natural cementation or plugging in sediments or rock formations. Petroleum microbiologists employed the process as a reservoir selective plugging method to enhance the production of hydrocarbon resources.</jats:p> <jats:p>Mineral precipitation is induced as a result of microbial activities. Bacteria can deposit minerals directly from the medium through their metabolic activities. They can also precipitate minerals indirectly from the medium by changing regional geological environmental conditions. Mineral precipitations and the dead bacteria bodies can persist as a part of the environment and result in plugging or cementing in pores in that environment. The process is optimized with bacteria Bacillus Pasteurii to precipitate CaCO3 so that the bacteriogenic cementation occurs in hours rather than in years. It is suggested that the process be used to plug fractures in water-producing zones to prevent excessive water production during oil recovery. The same technique can be used to consolidate sands in an unconsolidated fractures.</jats:p> <jats:p>A series of experiments was conducted to investigate the possibility of using microbial plugging process to remediate fractures and to test factors affecting that process. The effects of pH, temperature and medium on mineral precipitation and bacteria growth are studied in detail. Also, the effect of fracture width and fracture fillings is studied. It is found that the microbial mineral plugging technique is effective in plugging fractures.</jats:p>

Chioma Blaise Chikere, Memory Tekere, Rasheed Adeleke

• 0

<title>Abstract</title> <p><bold>Background: </bold>The frequency of crude oil pollution has been on the increase following increased exploration, exploitation and production of energy from fossil fuel. Bioremediation has been shown to be eco-friendly and cost-effective method of oil spill remediation. In the Niger Delta, Landfarming has been the most used technique. The aim of this research was to employ metagenomic techniques to understand microbial dynamics during field-scale remediation in the Niger Delta in order to improve and reduce the time of remediation. <bold>Results:</bold> The surface (0.0 – 0.5m) sample had an extractable TPH value of 6231 mg/kg. The subsurface samples from 1m, 1.5m and 2.0m depths had extractable TPH concentration of 4836 mg/kg, 9112 mg/kg and 7273 mk/kg respectively. Proteobacteria dominated the soil microbial profile in all the samples studied as it made up at least 50% of each sample and mostly comprised of the class Alphaproteobacteria with variation only on day 18 and 36 which was mostly dominated by the class Gammaproteobacteria and Betaproteobacteria. Alpha diversity analysis revealed the presence of crude oil in the soil reduced microbial diversity. Principal coordinate analysis showed the microbial structure continually changed following changes in the chemical composition of the soil. <italic>Mycobacterium</italic>, <italic>Burkholderia</italic>, <italic>Rhodoplanes</italic>, <italic>Methylobacterium</italic> and <italic>Bacillus</italic> were the core OTUs detected during the period of remediation. Significant variation in pathway abundance particularly pathways for propanoate degradation, benzoate degradation, naphthalene degradation, fatty acid metabolism, polycyclic aromatic hydrocarbon degradation and degradation of xenobiotics were observed when the unpolluted soil was compared to the samples obtained during remediation. <bold>Conclusions:</bold> The findings from this study will greatly advance an already preferred landfarming oil spill recovery technique in the Niger Delta.</p>

R. J. Portier, D. L. Sattler, D. G. Hoover et al.

Remediation Journal • 1998

<jats:title>Abstract</jats:title><jats:p>Well‐recovery networks coupled to immobilized microbe bioreactors (IMBRs) were installed at a 172‐acre former wood preserving facility for the bioremediation of organic wood preservatives present in site groundwater. Free‐phase creosote from the hardpan and soluble preservative fractions contained in subsurface groundwater were pumped separately to different holding tanks. Trace creosote fractions contained in the subsurface groundwater were further gravity separated in the holding tank. Immobilized microbial isolates evaluated in earlier laboratory and field pilot tests were established into two 40, 000‐liter bioreactors for the biodegradation of all targeted consitituents. Microbial growth, dissolved oxygen, pH, nutrients, flow rate, and temperature were monitored in this in situ/ex situ bioremediation system. The process was used to remove the polycyclic aromatic hydrocarbon (PAH) and phenolic components of creosote and pentachlorophenol from contaminated groundwater. Data generated during the past 2 1/2 years indicate that 26 target compounds consistently are reduced to levels acceptable for discharge. Currently operating in Baldwin, Florida, this full‐scale prototype is remediating the former wood preserving facility and is being used as a model system for the design and construction of new bioreactor systems needed at similar industrial sites in the United States and abroad.</jats:p>