Potential and Limits of Biodegradation Processes for the Removal of Organic Xenobiotics from Wastewaters (original) (raw)
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Materials, methods & technologies, 2019
The compounds as 1, 2-dibromoethane, 1, 2-dichloroethane and phenol are ones of the most dangerous pollutants in the environment. 1, 2-Dibromoethane (DBE) is a synthetic organic chemical that is mainly used as a gasoline additive. It is also one of the widely used pesticide fumigants. 1,2Dichloroethane is one of the most commonly used chlorinated industrial products and falls into the environment by using it as a chemical intermediate in the synthesis of a number of chlorinated hydrocarbons. Phenol is a waste product from the plastics, petroleum and pharmaceutical industries. There are different methods for treating wastewater containing the listed xenobiotics. Applied physicochemical methods are often economically ineffective and may cause other toxic products to occur. For this reason, microbiological treatment methods are preferred. We tested three different bacterial strains: Pseudomonas putida, Bradyrhizobium japonicum and Xanthobacter autotrophicus GJ10. In our studies for a p...
Biodegradation of Xenobiotics in Environment and Technosphere
The Handbook of Environmental Chemistry
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Degradation of Xenobiotic Pollutants: An Environmentally Sustainable Approach
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The ability of microorganisms to detoxify xenobiotic compounds allows them to thrive in a toxic environment using carbon, phosphorus, sulfur, and nitrogen from the available sources. Biotransformation is the most effective and useful metabolic process to degrade xenobiotic compounds. Microorganisms have an exceptional ability due to particular genes, enzymes, and degradative mechanisms. Microorganisms such as bacteria and fungi have unique properties that enable them to partially or completely metabolize the xenobiotic substances in various ecosystems.There are many cutting-edge approaches available to understand the molecular mechanism of degradative processes and pathways to decontaminate or change the core structure of xenobiotics in nature. These methods examine microorganisms, their metabolic machinery, novel proteins, and catabolic genes. This article addresses recent advances and current trends to characterize the catabolic genes, enzymes and the techniques involved in combat...
Includes bibliographical references and index. Issued in print and electronic formats. ISBN 978-1-77188-362-7 (hardcover).--ISBN 978-1-77188-363-4 (pdf) 1. Bioremediation. 2. Biodegradation. 3. Xenobiotics. 4. Sustainable development. I. . He has published more than 120 articles in peer-reviewed journals and conference proceedings, and has published many book chapters and technical reports on cell culture engineering, secondary metabolites, natural products, biomaterials, bioenergy, environmental remediation, drug delivery, photocatalysts, and chemical sensors. Dr. Abdullah obtained an MEng degree in chemical engineering and biotechnology from the University of Manchester Institute of Science and Technology, United Kingdom, under a PETRONAS Scholarship, and a PhD in Bioprocess Engineering from Universiti Putra Malaysia under a UPM Scholarship.
Degradation of xenobiotic compounds in situ: Capabilities and limits
FEMS Microbiology Reviews, 1994
Exploiting microorganisms for remediation of waste sites is a promising alternative to groundwater pumping and above ground treatment. The objective of in situ bioremediation is to stimulate the growth of indigenous or introduced microorganisms in regions of subsurface contamination, and thus to provide direct contact between microorganisms and the dissolved and sorbed contaminants for biotransformation. Subsurface microorganisms detected at a former manufactured gas plant site contaminated with coal tars mineralized significant amounts of naphthalene (8 43%) and phenanthrene (3-31%) in sediment-water microcosms incubated for 4 weeks under aerobic conditions. Evidence was obtained for naphthalene mineralization (8-13%) in the absence of oxygen in field samples. These data suggest that biodegradation of these compounds is occurring at the site, and the prospects are good for enhancing this biodegradation. Additional batch studies demonstrated that sorption of naphthalene onto aquifer materials reduced the extent and rate of biodegradation, indicating that desorption rate was controlling the biodegradation performance.
Applied Microbiology and Biotechnology, 1999
Chloroaromatic compounds are xenobiotics that cause great concern. The degradation of a model molecule, 3,4-dichlorobenzoate (3,4-DCB), was studied using three aerobic (AE)-anaerobic (AN) biofilm reactor systems: a coupled aerobic-anaerobic recycle biofilm reactor (CAR) system, an in-series anaerobic-aerobic biofilm reactor (SAR) system; and an independent aerobic and anaerobic biofilm reactor (IAR) system. In all three systems the inlet substrate concentration was 2.0 g/l and the dilution rates ranged from 0.045 to 0.142 per hour. The results show that the degradation efficiency of the CAR system (expressed as dechlorination and xenobiotic disappearance efficiencies, and biomass yield), was higher at all dilution rates tested than in both SAR and IAR systems. Moreover, dechlorination and xenobiotic disappearance efficiencies for resting suspended aerobic and anaerobic cells or mixed aerobic-anaerobic growing cells under anaerobic conditions were higher than under aerobic conditions. These results suggest that a “cooperative metabolism” between aerobic and anaerobic bacteria (caused by an exchange of cells and metabolites between AE and AN reactors) in the CAR system overcame the metabolic and kinetic limitations of aerobic and anaerobic bacteria in the AE and AN reactors of IAR and SAR systems. Therefore, the degradation efficiency of persistent and recalcitrant chloroaromatic xenobiotic compounds could be enhanced by using a CAR system.
Microbial diversity: Application of micro- organisms for the biodegradation of xenobiotics
2005
Environmental pollution caused by the release of a wide range of compounds as a consequence of industrial progress has now assumed serious proportions. Thousands of hazardous waste sites have been generated worldwide resulting from the accumulation of xenobiotics in soil and water over the years. Nitroaromatic compounds (NACs), polycyclic aromatics and other hydrocarbons (PAHs) that are constituents of crude oil, and halogenated organic compounds together constitute a large and diverse group of chemicals that are responsible for causing widespread environmental pollution. The physico-chemical remedial strategies to clean up sites contaminated by these compounds are not cost effective or adequate enough. Therefore, research is increasingly being focused on biological methods for the degradation and elimination of these pollutants. Sites contaminated by these compounds need urgent remedial solutions, the search for which has revealed a diverse range of bacteria that can utilize these xenobiotics as substrates, often mineralizing them or converting them into harmless products, and in the process helping to clean up the environment. New genes, enzymes and metabolic routes involved in bacterial degradation of PAHs, NACs and halogenated organic compounds (HOCs) have been discovered, and new methods have been developed which allow the discovery and broad flexibility of microorganisms in environmental clean up. Studies to understand the interaction between xenobiotics and microorganisms in the environment have to intersect with biochemical and genetic engineering areas. Such a strategy will provide the ground for successful interventions into environmental processes and ultimately lead to optimized strategies for tapping of microbial diversity for efficient and effective bioremediation of xenobiotics.
Potential for Anaerobic Conversion of Xenobiotics
Advances in Biochemical Engineering/Biotechnology, 2003
This review covers the latest research on the anaerobic biodegradation of aromatic xenobiotic compounds, with emphasis on surfactants, polycyclic aromatic hydrocarbons, phthalate esters, polychlorinated biphenyls, halogenated phenols, and pesticides. The versatility of anaerobic reactor systems regarding the treatment of xenobiotics is shown with the focus on the UASB reactor, but the applicability of other reactor designs for treatment of hazardous waste is also included. Bioaugmentation has proved to be a viable technique to enhance a specific activity in anaerobic reactors and recent research on reactor and in situ bioaugmentation is reported.
Classical and New Aspects in Degradation of Aromatic Xenobiotics
Ecological Engineering and Environment Protection
Organic chemical mixtures are prevalent in waste waters from industrial and municipal sources as well as in contaminated groundwater. Phenols are pollutants found in wastewaters from oil refineries, chemical plants, explosives, resins and coke manufacture, coal conversion, pesticide and textile industries. The main contaminants of refinery wastewater include phenols, polycyclic aromatic hydrocarbons (PAHs) as well as heavy metals. Among these toxic pollutants, phenols are considered to be the most hazardous ones, and they are certainly the most difficult to remove. Phenolic compounds are toxic at relatively low concentration. Because of these low concentrations the most suitable methods for their removal are the microbial ones. The present work is a review of biodegradation of phenol. Degradation of phenol occurs as a result of the activity of a large number of microorganisms including bacteria, fungi and actinomycetes. There are reports on ma33ny microorganisms capable of degrading...