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At least 19 recordsLinked to original sources

PubMed1996

Straw compost and bioremediated soil as inocula for the bioremediation of chlorophenol-contaminated soil.

We evaluated the use of straw compost and remediated soil as inocula for bioremediation of chlorophenol-contaminated soil. The in situ biotransformation of pentachlorophenol (PCP) and mineralization of radiolabeled [U-(sup14)C]PCP by straw compost and remediated soil were studied under field-simulating conditions before and after 3 months of adaptation with PCP in a percolator. After PCP adaptation, the straw compost mineralized up to 56% of the [(sup14)C]PCP. No partial dechlorination of PCP was found. The native straw compost did not mineralize PCP, but partial dechlorination of PCP occurred (i) at pH 8 under near-thermophilic conditions (45(deg)C) and (ii) at pH 7 under aerobic and mesophilic conditions. No biotransformation reactions occurred at room temperature (25(deg)C) at pH 8. Enrichment in the percolator enhanced the mineralization rate of remediated soil to 56% compared with that of the native remediated soil, which mineralized 24% of [(sup14)C]PCP added. Trace amounts of chloroanisoles as the only biotransformation products were detected in PCP-adapted remediated soil. Both inoculants studied here showed effective mineralization of PCP when they were adapted to PCP in the percolator. No harmful side reactions, such as extensive methylation, were observed.

Journal Article↗

PubMed2005

Impact of microbial activity on copper, lead and nickel mobilization during the bioremediation of soil PAHs.

A fungal bioremediation method using P. frequentans removed up to 75% of phenanthrene with the addition of water and nutrients over a period of 30 d. During the bioremediation process, changes in metal behavior were monitored by an in situ technique (diffusive gradients in thin-films, DGT) and by soil solution chemistry. DGT provided absolute data on fluxes from the solid phase to the DGT device and relative trends of concentrations of the most labile metal species. DGT response indicated that bioremediation increases metal mobilization from the solid phase. Filtration provided data on the concentrations of solution phase (<0.45 microm) metal. In all case, metal fluxes and concentrations significantly increased after the bioremediation process began. Fluxes increased from <0.1 pg cm(-2)s(-1) before bioremediation to between 0.2 and 0.5 pg cm(-2)s(-1) after bioremediation. Metal concentrations in the soils solution (filtration at 0.45 microm) increased from 2 to 10 microg l(-1) (Cu), 1-4 microgl(-1) (Pb) and from 40 to 140 microg l(-1) (Ni) after bioremediation. Although over a short time period, these data strongly indicated that there was remobilization of metal from solid to solution (and thus to the DGT device) directly due to the bioremediation process. Although the mechanism was not unambiguously identified, it was shown not to be related to small changes in bulk pH over time and was attributed to the microbial action on the surface of the soil solid phase, releasing metal into solution. Additionally, differences in metal concentration and flux were observed in sterilized and non-sterilized soils and in the absence or presence of phenanthrene. The results indicated that the bioremediation of soil by P. frequentans increased the flux, lability and mobility of trace metal species and therefore the likely metal bioavailability to plants.

Biodegradation, Environmental↗

PubMed2004

Bioremediation of coastal areas 5 years after the Nakhodka oil spill in the Sea of Japan: isolation and characterization of hydrocarbon-degrading bacteria.

Five years after the 1997 Nakhodka oil spill in the Sea of Japan, seven bacterial strains capable of utilizing the heavy oil spilled from the Nakhodka Russian oil tanker were isolated from three coastal areas (namely Katano Seashore of Fukui Prefecture, Osawa and Atake seashores of Ishikawa Prefecture) and the Nakhodka Russian oil tanker after a 5-year bioremediation process. All bacterial strains isolated could utilize long-chain-length alkanes efficiently, but not aromatic, and all of them were able to grow well on heavy oil. Using 16S rDNA sequencing, most of the strains were affiliated to Pseudomonas aeruginosa. Comparing between the year 1997 (at the beginning of bioremediation process) and the year 2001 (after 5 years of bioremediation), there was no significant change in morphology and size of hydrocarbon-degrading bacteria during the 5-year bioremediation. Scanning and transmission electron microscopic observations revealed that a large number of hydrocarbon-degrading bacteria still existed in the sites consisting of a variety of morphological forms of bacteria, such as coccus (Streptococcus and Staphylococcus) and bacillus (Streptobacillus). On the application of bioremediation processes on the laboratory-scale, laboratory microcosm experiments (containing seawater, beach sand, and heavy oil) under aerobic condition by two different treatments (i.e., placed the inside building and the outside building) were established for bioremediation of heavy oil to investigate the significance of the role of hydrocarbon-degrading bacteria on them. There was no significant bacterial activity differentiation in the two treatments, and removal of heavy oil by hydrocarbon-degrading bacteria in the outside building was slightly greater than that in the inside building. The values of pH, Eh, EC, and dissolved oxygen (DO) in two treatments indicated that the bioremediation process took place under aerobic conditions (DO: 1-6 mg/l; Eh: 12-300 mV) and neutral-alkaline conditions (pH 6.4-8) with NaCl concentrations of 3-15% (ECs of 45-200 mS/cm).

Bacteria↗

PubMed2006

Bioavailable cadmium during the bioremediation of phenanthrene-contaminated soils using the diffusive gradients in thin-film technique.

AIMS: To study the impact of fungal bioremediation of phenanthrene on trace cadmium solid-solution fluxes and solution phase concentration. METHODS AND RESULTS: The bioremediation of phenanthrene in soils was performed using the fungus Penicillium frequentans. Metal behaviour was evaluated by the techniques of diffusive gradient in thin-films (DGT) and filtration. Fluxes of cadmium (Cd) show a significant (P < 0.002) increase after the start of bioremediation, indicating that the bioremediation process itself releases significant amount of Cd into solution from the soil solid-phase. Unlike DGT devices, the solution concentration from filtration shows a clear bimodal distribution. We postulate that the initial action of the fungi is most likely to breakdown the surface of the solid phase to smaller, 'solution-phase' material (<0.45 microm) leading to a peak in Cd concentration in solution. CONCLUSIONS: Phenanthrene removal from soils by bioremediation ironically results in the mobilization of another toxic pollutant (Cd). SIGNIFICANCE AND IMPACT OF THE STUDY: Bioremediation of organic pollutants in contaminated soil will likely lead to large increases in the mobilization of toxic metals, increasing metal bio-uptake and incorporation into the wider food chain. Bioremediation strategies need to account for this behaviour and further research is required both to understand the generality of this behaviour and the operative mechanisms.

Biodegradation, Environmental↗

PubMed2007

Strong impact on the polycyclic aromatic hydrocarbon (PAH)-degrading community of a PAH-polluted soil but marginal effect on PAH degradation when priming with bioremediated soil dominated by mycobacteria.

Bioaugmentation of soil polluted with polycyclic aromatic hydrocarbons (PAHs) is often disappointing because of the low survival rate and low activity of the introduced degrader bacteria. We therefore investigated the possibility of priming PAH degradation in soil by adding 2% of bioremediated soil with a high capacity for PAH degradation. The culturable PAH-degrading community of the bioremediated primer soil was dominated by Mycobacterium spp. A microcosm containing pristine soil artificially polluted with PAHs and primed with bioremediated soil showed a fast, 100- to 1,000-fold increase in numbers of culturable phenanthrene-, pyrene-, and fluoranthene degraders and a 160-fold increase in copy numbers of the mycobacterial PAH dioxygenase gene pdo1. A nonpolluted microcosm primed with bioremediated soil showed a high rate of survival of the introduced degrader community during the 112 days of incubation. A nonprimed control microcosm containing pristine soil artificially polluted with PAHs showed only small increases in the numbers of culturable PAH degraders and no pdo1 genes. Initial PAH degradation rates were highest in the primed microcosm, but later, the degradation rates were comparable in primed and nonprimed soil. Thus, the proliferation and persistence of the introduced, soil-adapted degraders had only a marginal effect on PAH degradation. Given the small effect of priming with bioremediated soil and the likely presence of PAH degraders in almost all PAH-contaminated soils, it seems questionable to prime PAH-contaminated soil with bioremediated soil as a means of large-scale soil bioremediation.

Arthrobacter↗

PubMed2004

Response of Archaeal communities in beach sediments to spilled oil and bioremediation.

While the contribution of Bacteria to bioremediation of oil-contaminated shorelines is well established, the response of Archaea to spilled oil and bioremediation treatments is unknown. The relationship between archaeal community structure and oil spill bioremediation was examined in laboratory microcosms and in a bioremediation field trial. 16S rRNA gene-based PCR and denaturing gradient gel analysis revealed that the archaeal community in oil-free laboratory microcosms was stable for 26 days. In contrast, in oil-polluted microcosms a dramatic decrease in the ability to detect Archaea was observed, and it was not possible to amplify fragments of archaeal 16S rRNA genes from samples taken from microcosms treated with oil. This was the case irrespective of whether a bioremediation treatment (addition of inorganic nutrients) was applied. Since rapid oil biodegradation occurred in nutrient-treated microcosms, we concluded that Archaea are unlikely to play a role in oil degradation in beach ecosystems. A clear-cut relationship between the presence of oil and the absence of Archaea was not apparent in the field experiment. This may have been related to continuous inoculation of beach sediments in the field with Archaea from seawater or invertebrates and shows that the reestablishment of Archaea following bioremediation cannot be used as a determinant of ecosystem recovery following bioremediation. Comparative 16S rRNA sequence analysis showed that the majority of the Archaea detected (94%) belonged to a novel, distinct cluster of group II uncultured Euryarchaeota, which exhibited less than 87% identity to previously described sequences. A minor contribution of group I uncultured Crenarchaeota was observed.

Biodegradation, Environmental↗

PubMed1997

Healthy environments for healthy people: bioremediation today and tomorrow.

Increases in environmental contamination lead to a progressive deterioration of environmental quality. This condition challenges our global society to find effective measures of remediation to reverse the negative conditions that severely threaten human and environmental health. We discuss the progress being made toward this goal through application of bioremediation techniques. Bioremediation generally utilizes microbes (bacteria, fungi, yeast, and algae), although higher plants are used in some applications. New bioremediation approaches are emerging based on advances in molecular biology and process engineering. Bioremediation continues to be the favored approach for processing biological wastes and avoiding microbial pathogenesis. Bioremediation may also play an increasing role in concentrating metals and radioactive materials to avoid toxicity or to recover metals for reuse. Microbes can biodegrade organic chemicals; purposeful enhancement of this natural process can aid in pollutant degradation and waste-site cleanup operations. Recently developed rapid-screening assays can identify organisms capable of degrading specific wastes and new gene-probe methods can ascertain their abundance at specific sites. New tools and techniques for use of bioremediation in situ, in biofilters, and in bioreactors are contributing to the rapid growth of this field. Bioremediation has already proven itself to be a cost-effective and beneficial addition to chemical and physical methods of managing wastes and environmental pollutants. We anticipate that it will play an increasingly important role as a result of new and emerging techniques and processes.

Animals↗

PubMed2004

[Issues concerned with the bioremediation of contaminated soils].

Several issues faced in the process of bioremediation were discussed in this paper, which are included as below: The principal and condition for the introducing of foreigner microbial; Mechanisms of suitability for microorganisms in the bioremediation process and the factors that influenced the degradation of pollutants; The correlations between the concentration of pollutants and their bioremediation; The secondary pollutants in the process of degradation of organic chemicals; The technology amplification of bioremediation technique on situ or/and in situ; the leaching process of contaminants; The Eco-toxicological diagnosis and evaluation for bioremediation technology and so on in order to enhance the realization for problems existed in the process of bioremediation and make it possible for more effective application of the bioremediation technology.

Biodegradation, Environmental↗

PubMed2005

Ecotoxicological evaluation of diesel-contaminated soil before and after a bioremediation process.

Evaluation of contaminated sites is usually performed by chemical analysis of pollutants in soil. This is not enough either to evaluate the environmental risk of contaminated soil nor to evaluate the efficiency of soil cleanup techniques. Information on the bioavailability of complex mixtures of xenobiotics and degradation products cannot be totally provided by chemical analytical data, but results from bioassays can integrate the effects of pollutants in complex mixtures. In the preservation of human health and environment quality, it is important to assess the ecotoxicological effects of contaminated soils to obtain a better evaluation of the healthiness of this system. The monitoring of a diesel-contaminated soil and the evaluation of a bioremediation technique conducted on a microcosm scale were performed by a battery of ecotoxicological tests including phytotoxicity, Daphnia magna, and nematode assays. In this study we biostimulated the native microflora of soil contaminated with diesel by adding nutrients and crop residue (corn straw) as a bulking agent and as a source of microorganisms and nutrients; in addition, moisture was adjusted to enhance diesel removal. The bioremediation process efficiency was evaluated directly by an innovative, simple phytotoxicity test system and the diesel extracts by Daphnia magna and nematode assays. Contaminated soil samples were revealed to have toxic effects on seed germination, seedling growth, and Daphnia survival. After biostimulation, the diesel concentration was reduced by 50.6%, and the soil samples showed a significant reduction in phytotoxicity (9%-15%) and Daphnia assays (3-fold), confirming the effectiveness of the bioremediation process. Results from our microcosm study suggest that in addition to the evaluation of the bioremediation processes efficiency, toxicity testing is different with organisms representative of diverse phylogenic levels. The integration of analytical, toxicological and bioremediation data is necessary to properly assess the ecological risk of bioremediation processes.

Animals↗

PubMed2003

Monitoring of white-rot fungus during bioremediation of polychlorinated dioxin-contaminated fly ash.

Bioremediation is a low-cost treatment alternative for the cleanup of polychlorinated-dioxin-contaminated soils and fly ash when pollution spread is wide-ranging. An interesting fungus, Ceriporia sp. MZ-340, with a high ability to degrade dioxin, was isolated from white rotten wood of a broadleaf tree from Kyushu Island in Japan. We have attempted to use the fungus for bioremediation of polychlorinated-dioxin-contaminated soil on site. However, we have to consider that this trial has the potential problem of introducing a biohazard to a natural ecosystem if this organism is naturalized. We have therefore developed a monitoring system for the introduced fungus as a part of the examination and evaluation of bioremediation in our laboratory. We have also developed a PCR-based assay to reliably detect the fungus at the bioremediation site. DNA isolated from the site was amplified by PCR using a specific primer derived from internal transcribed spacer region (ITS: ITS1, 5.8S rDNA and ITS2) sequences of Ceriporia sp. MZ-340. We successfully monitored Ceriporia sp. MZ-340 down to 100 fg/ micro l DNA and down to 2 mg/g mycelium. We also successfully monitored the fungus specifically at the bioremediation site. The polychlorinated dibenzo- p-dioxin and polychlorinated dibenzofuran content was observed to decrease in response to treatment with the fungus. The species-specific PCR technique developed in the present work is useful in evaluating the possibility of on-site bioremediation using the fungus Ceriporia sp. MZ-340.

Air Pollutants↗

PubMed2000

Estimating the availability of polycyclic aromatic hydrocarbons for bioremediation of creosote contaminated soils.

Bioremediation of soil contaminated by organic compounds can remove the contaminants to a large extent, but residual contamination levels may remain which are not or only slowly biodegraded. Residual levels often exceed existing clean-up guidelines and thereby limit the use of bioremediation in site clean-up. A method for estimating the expected residual levels would be a useful tool in the assessment of the feasibility of bioremediation. In this study, three soil types from a creosote-contaminated field site, which had been subjected to 6 months of bioremediation in laboratory column studies, were used to characterize the residual contamination levels and assess their availability for biodegradation. The soils covered a wide range of organic carbon levels and particle size distributions. Results from the biodegradation studies were compared with desorption rate measurements and selective extractability using butanol. Residual levels of polycyclic aromatic hydrocarbons after bioremediation were found to be strongly dependent on soil type. The presence of both soil organic matter and asphaltic compounds in the soil was found to be associated with higher residual levels. Good agreement was found between the biodegradable fraction and the rapidly desorbable fraction in two of the three soils studied. Butanol extraction was found to be a useful method for roughly estimating the biodegradable fraction in the soil samples. The results indicate that both desorption and selective extraction measurements could aid the assessment of the feasibility for bioremediation and identifying acceptable end-points.

Biodegradation, Environmental↗

PubMed2005

Assessment of genotoxic activity of petroleum hydrocarbon-bioremediated soil.

The relationship between toxicity and soil contamination must be understood to develop reliable indicators of environmental restoration for bioremediation. Two bacterial rapid bioassays, SOS chromotest and the umu test with and without metabolic activation (S-9 mixture), were used to evaluate the genotoxicity of petroleum hydrocarbon-contaminated soil following bioremediation treatment. The soil was taken from an engineered biopile at the Czechowice-Dziedzice Polish oil refinery (CZOR). The bioremediation process in the biopile lasted 4 years, and the toxicity measurements were done after this treatment. Carcinogens detected in the soil, polyaromatic hydrocarbons (PAHs), were reduced to low concentrations (2mg/kg dry wt) by the bioremediation process. Genotoxicity was not observed for soils tested with and without metabolic activation by a liver homogenate (S-9 mixture). However, the umu test was more sensitive than the SOS chromotest in the analysis of petroleum hydrocarbon-bioremediated soil. Analytical results of soil used in the bioassays confirmed that the bioremediation process reduced 81% of the petroleum hydrocarbons including PAHs. We conclude that the combined test systems employed in this study are useful tools for the genotoxic examination of remediated petroleum hydrocarbon-contaminated soil.

Biodegradation, Environmental↗

PubMed2004

Mass transfer and bioremediation of naphthalene particles in a roller bioreactor.

Naphthalene particles in a water slurry have been bioremediated in a sealed, roller bioreactor using a pure strain of Pseudomonas putida. High stripping losses of particles due to both splashing and aeration made the use of the traditional CSTR bioreactor unsuitable for bioremediation of naphthalene particles. The overall dissolution mass transfer coefficient of naphthalene particles in the roller bioreactor was low, 0.055 h(-1) at 50 RPM. The dissolution mass transfer rate was the limiting step for bioremediation. Although mass transfer was identified as the rate limiting step, the addition of hydroxypropyl-beta-cyclodextrin (a solubility enhancer) failed to improve naphthalene slurry bioremediation. In order to successfully bioremediate naphthalene particles at concentrations over 300 mg/L, intermittent aeration was applied in the sealed roller bioreactor on a daily basis. By operating in sequential batch mode with intermittent aeration, the roller bioreactor was successfully used to continuously bioremediate naphthalene particles at concentrations up to 1000 mg/L and at rates up to 10 mg/Lh.

2-Hydroxypropyl-beta-cyclodextrin↗

PubMed2002

Engineered and subsequent intrinsic in situ bioremediation of a diesel fuel contaminated aquifer.

A diesel fuel contaminated aquifer in Menziken, Switzerland was treated for 4.5 years by injecting aerated groundwater, supplemented with KNO3 and NH4H2PO4 to stimulate indigenous populations of petroleum hydrocarbon (PHC) degrading microorganisms. After dissolved PHC concentrations had stabilized at a low level, engineered in situ bioremediation was terminated. The main objective of this study was to evaluate the efficacy of intrinsic in situ bioremediation as a follow-up measure to remove PHC remaining in the aquifer after terminating engineered in situ bioremediation. In the first 7 months of intrinsic in situ bioremediation, redox conditions in the source area became more reducing as indicated by lower concentrations of SO4(2-) and higher concentrations of Fe(II) and CH4. In the core of the source area, strongly reducing conditions prevailed during the remaining study period (3 years) and dissolved PHC concentrations were higher than during engineered in situ bioremediation. This suggests that biodegradation in the core zone was limited by the availability of oxidants. In lateral zones of the source area, however, gradually more oxidized conditions were reestablished again, suggesting that PHC availability increasingly limited biodegradation. The total DIC production rate in the aquifer decreased within 2 years to about 25% of that during engineered in situ bioremediation and remained at that level. Stable carbon isotope analysis confirmed that the produced DIC mainly originated from PHC mineralization. The total rate of DIC and CH4 production in the source area was more than 300 times larger than the rate of PHC elution. This indicates that biodegradation coupled to consumption of naturally occurring oxidants was an important process for removal of PHC which remained in the aquifer after terminating engineered measures.

Biodegradation, Environmental↗

PubMed1999

Bioremediation of petroleum hydrocarbon contaminants in marine habitats.

Bioremediation is being increasingly seen as an effective, environmentally benign treatment for shorelines contaminated as a result of marine oil spills. Despite a relatively long history of research on oil-spill bioremediation, it remains an essentially empirical technology and many of the factors that control bioremediation have yet to be adequately understood. Nutrient amendment is a widely accepted practice in oil-spill bioremediation but there is scant understanding of the systematic effects of nutrient amendment on biodegradative microbial populations or the progress of bioremediation. Recent laboratory and field research suggests that resource-ratio theory may provide a theoretical framework that explains the effects of nutrient amendment on indigenous microbial populations. In particular, the theory has been invoked to explain recent observations that nutrient levels, and their relative concentration, influence the composition of hydrocarbon-degrading microbial populations. This in turn influences the biodegradation rate of aliphatic and aromatic hydrocarbons. If such results are confirmed in the field, then it may be possible to use this theoretical framework to select bioremediation treatments that specifically encourage the rapid destruction of the most toxic components of complex pollutant mixtures.

Anaerobiosis↗

PubMed2006

In-situ surfactant/surfactant-nutrient mix-enhanced bioremediation of NAPL (fuel)-contaminated sandy soil aquifers.

SCOPE AND BACKGROUND: Contamination of soils, aquifers and groundwater by nonaqueous phase liquid (NAPL) pollutants constitutes a major environmental issue of concern, worldwide. The residual (biodegradation-resistant) hydrophobic fuel hydrocarbons entrapped in the soil porous matrix, possess a particular bioremediation challenge due to their becoming virtually immobile, nor desorbable, or water dispersible. Consequently, they are not available as substrates to the micro-organism-based biodegradation. MATERIALS AND METHODS: Our research involves the development of economically feasible, surfactant/surfactant-nutrient mix (SSNM)-enhanced bioremediation methodologies for sustainable, in situ bioremediation of fuel-contaminated aquifers. This requires, methodologically, (a) the optimization, via in vitro 'flow' (columns) lab experiments and screening processes, of an effective mixture for the intended SSNM-enhanced bioremediation; and (b) the study of the combined effect of the optimized SSNM on the solubilization/mobilization and biodegradation of NAPL (fuel) in in vitro site/aquifer-simulated bioremediation. RESULTS AND DISCUSSION: The essence of our findings: (1) kerosene's maximum enhanced mobilization - f = 3.6, compared with that of deionized water, was achieved with an SSNM having the composition of linear alkylbenzene sulfonate (LABS): coco-amphodiacetate (containing N): surfactant-nutrient X (containing both N and P) = 0.15: 0.15: 0.05 g/L, respectively; (2) 62-64% of the initial amount of kerosene in the initially saturated soil matrix, 'packed' in a column, has been eluted from it during approximately 30 days, compared with 68% of kerosene biodegradation in 'vessel' settings, in 21 days. CONCLUSIONS: (1) The indigenous microorganisms present in th vadose zones of fuel-contaminated sandy soil aquifers are potentially capable of unassisted removal of approximately 80% of the initially contained fuel (kerosene), during a period of about 42 days; (2) the major effects of the SSNM addition are (a) enhanced mobilization of the bulky NAPL; and (b) enhanced desorbtion/ solubilization/dispersion of the entrapped NAPL which, in turn, facilitate their enhanced biodegradation. RECOMMENDATIONS AND PERSPECTIVE: Our findings suggest that pre-optimized, biodegradable SSNM is essential for surfactants-based bioremediation of NAPL-contaminated aquifers, in order to make this in-situ methodology both technologically and economically feasible.

Biodegradation, Environmental↗

PubMedDate not supplied

Use of genetically engineered microorganisms (GEMs) for the bioremediation of contaminants.

This paper presents a critical review of the literature on the application of genetically engineered microorganisms (GEMs) in bioremediation. The important aspects of using GEMs in bioremediation, such as development of novel strains with desirable properties through pathway construction and the modification of enzyme specificity and affinity, are discussed in detail. Particular attention is given to the genetic engineering of bacteria using bacterial hemoglobin (VHb) for the treatment of aromatic organic compounds under hypoxic conditions. The application of VHb technology may advance treatment of contaminated sites, where oxygen availability limits the growth of aerobic bioremediating bacteria, as well as the functioning of oxygenases required for mineralization of many organic pollutants. Despite the many advantages of GEMs, there are still concerns that their introduction into polluted sites to enhance bioremediation may have adverse environmental effects, such as gene transfer. The extent of horizontal gene transfer from GEMs in the environment, compared to that of native organisms including benefits regarding bacterial bioremediation that may occur as a result of such transfer, is discussed. Recent advances in tracking methods and containment strategies for GEMs, including several biological systems that have been developed to detect the fate of GEMs in the environment, are also summarized in this review. Critical research questions pertaining to the development and implementation of GEMs for enhanced bioremediation have been identified and posed for possible future research.

Bacteria↗

PubMed2001

Current bioremediation practice and perspective.

The use of microbes to clean up polluted environments, bioremediation, is a rapidly changing and expanding area of environmental biotechnology. Although bioremediation is a promising approach to improve environmental conditions, our limited understanding of biological contribution to the effect of bioremediation and its impact on the ecosystem has been an obstacle to make the technology more reliable and safer. Providing fundamental data to resolve these issues, i.e., the behavior of the target bacteria directly related to the degradation of contaminants and the changes in microbial communities during bioremediation, has been a challenge for microbiologists since many environmental bacteria cannot yet be cultivated by conventional laboratory techniques. The application of culture-independent molecular biological techniques offers new opportunities to better understand the dynamics of microbial communities. Fluorescence in situ hybridization (FISH), in situ PCR, and quantitative PCR are expected to be powerful tools for bioremediation to detect and enumerate the target bacteria that are directly related to the degradation of contaminants. Nucleic acid based molecular techniques for fingerprinting the 16S ribosomal DNA (rDNA) of bacterial cells, i.e., denaturing gradient gel electrophoresis (DGGE) and terminal restriction fragment length polymorphism (T-RFLP), enable us to monitor the changes in bacterial community in detail. Such advanced molecular microbiological techniques will provide new insights into bioremediation in terms of process optimization, validation, and the impact on the ecosystem, which are indispensable data to make the technology reliable and safe.

Journal Article↗