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Microbial biodegradation

About: Microbial biodegradation is a research topic. Over the lifetime, 1647 publications have been published within this topic receiving 75473 citations.


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Journal ArticleDOI
TL;DR: This minireview considers the ability of AOB to carry out cometabolism of halogenated compounds and the consequent inhibition of nitrification in ammonia-oxidizing bacteria in Nitrosomonas europaea.
Abstract: The process of nitrification has the potential for the in situ bioremediation of halogenated compounds provided a number of challenges can be overcome. In nitrification, the microbial process where ammonia is oxidized to nitrate, ammonia-oxidizing bacteria (AOB) are key players and are capable of carrying out the biodegradation of recalcitrant halogenated compounds. Through industrial uses, halogenated compounds often find their way into wastewater, contaminating the environment and bodies of water that supply drinking water. In the reclamation of wastewater, halogenated compounds can be degraded by AOB but can also be detrimental to the process of nitrification. This minireview considers the ability of AOB to carry out cometabolism of halogenated compounds and the consequent inhibition of nitrification. Possible cometabolism monitoring methods that were derived from current information about AOB genomes are also discussed. AOB expression microarrays have detected mRNA of genes that are expressed at higher levels during stress and are deemed “sentinel” genes. Promoters of selected “sentinel” genes have been cloned and used to drive the expression of gene-reporter constructs. The latter are being tested as early warning biosensors of cometabolism-induced damage in Nitrosomonas europaea with promising results. These and other biosensors may help to preserve the tenuous balance that exists when nitrification occurs in waste streams containing alternative AOB substrates such as halogenated hydrocarbons.

39 citations

Journal ArticleDOI
TL;DR: Results indicate that atrazine is not degraded by bacteria but bound, thus simulating biodegradation, and evidence is presented that physicochemical decomposition of the herbicide is more significant than microbial degradation.
Abstract: Degradation of14C-ring labeled atrazine (2-choloro-4-(ethylamino)-6-(isopropylamino)-s-triazine) by bacterial populations from soil, waters and activated sludges was investigated and compared with non-biological decomposition in sterile solutions. Within two weeks, 0.6% Cl-deethyl- and 0.1% Cl-deisopropylatrazine had been formed in sterile 0.02 M phosphate buffer, pH 7.2. In biodegradation studies, bacterial populations were enriched and incubated in media containing atrazine and high or low levels of nutrients. Nutrient supply had a strong effect on the fate of atrazine in bacterial cultures, whereas the origin of bacteria was of minor importance. In 31 of 33 mixed populations investigated, the herbicide was largely converted to unidentified compounds. Incubation with high levels of nutrients resulted in 17% to 57% of these compounds being constant after one and two weeks of incubation. In parallel experiments with low nutrient supply, the compounds were present in amounts of 7% to 57% after one week. The proportions of the unidentified compounds dropped within the second week of incubation, while atrazine reappeared correspondingly. The amounts of dealkylated metabolites generally did not exceed those of sterile solutions. The results indicate that atrazine is not degraded by bacteria but bound, thus simulating biodegradation. Evidence is presented that physicochemical decomposition of the herbicide is more significant than microbial degradation.

39 citations

Journal ArticleDOI
TL;DR: In this article, an in situ experiment was performed in a shallow alluvial aquifer in Maryland to quantify the fractionation of stable isotopes in perchlorate (Cl and O) and nitrate (N and O), resulting from biodegradation in an aquifer.
Abstract: Environmental context Perchlorate (ClO4–) and nitrate (NO3–) are common co-contaminants in groundwater, with both natural and anthropogenic sources Each of these compounds is biodegradable, so in situ enhanced bioremediation is one alternative for treating them in groundwater Because bacteria typically fractionate isotopes during biodegradation, stable isotope analysis is increasingly used to distinguish this process from transport or mixing-related decreases in contaminant concentrations However, for this technique to be useful in the field to monitor bioremediation progress, isotope fractionation must be quantified under relevant environmental conditions In the present study, we quantify the apparent in situ fractionation effects for stable isotopes in ClO4– (Cl and O) and NO3– (N and O) resulting from biodegradation in an aquifer Abstract An in situ experiment was performed in a shallow alluvial aquifer in Maryland to quantify the fractionation of stable isotopes in perchlorate (Cl and O) and nitrate (N and O) during biodegradation An emulsified soybean oil substrate that was previously injected into this aquifer provided the electron donor necessary for biological perchlorate reduction and denitrification During the field experiment, groundwater extracted from an upgradient well was pumped into an injection well located within the in situ oil barrier, and then groundwater samples were withdrawn for the next 30 h After correction for dilution (using Br– as a conservative tracer of the injectate), perchlorate concentrations decreased by 78% and nitrate concentrations decreased by 82% during the initial 86 h after the injection The observed ratio of fractionation effects of O and Cl isotopes in perchlorate (ϵ18O/ϵ37Cl) was 26, which is similar to that observed in the laboratory using pure cultures (25) Denitrification by indigenous bacteria fractionated O and N isotopes in nitrate at a ratio of ~08 (ϵ18O/ϵ15N), which is within the range of values reported previously for denitrification However, the magnitudes of the individual apparent in situ isotope fractionation effects for perchlorate and nitrate were appreciably smaller than those reported in homogeneous closed systems (02 to 06 times), even after adjustment for dilution These results indicate that (1) isotope fractionation factor ratios (ϵ18O/ϵ37Cl, ϵ18O/ϵ15N) derived from homogeneous laboratory systems (eg pure culture studies) can be used qualitatively to confirm the occurrence of in situ biodegradation of both perchlorate and nitrate, but (2) the magnitudes of the individual apparent ϵ values cannot be used quantitatively to estimate the in situ extent of biodegradation of either anion

39 citations

Journal ArticleDOI
TL;DR: In this article, the role of plants and microbes in the microbial degradation of petroleum hydrocarbons in contaminated soil is discussed and some important factors necessary for development of in situ bioremediation strategies for risks mitigation in petroleum hydrocarbon-contaminated soil.
Abstract: Petroleum hydrocarbons contamination of soil, sediments and marine environment associated with the inadvertent discharges of petroleum–derived chemical wastes and petroleum hydrocarbons associated with spillage and other sources into the environment often pose harmful effects on human health and the natural environment, and have negative socio–economic impacts in the oil–producing host communities. In practice, plants and microbes have played a major role in microbial transformation and growth–linked mineralization of petroleum hydrocarbons in contaminated soils and/or sediments over the past years. Bioremediation strategies has been recognized as an environmental friendly and cost–effective alternative in comparison with the traditional physico-chemical approaches for the restoration and reclamation of contaminated sites. The success of any plant–based remediation strategy depends on the interaction of plants with rhizospheric microbial populations in the surrounding soil medium and the organic contaminant. Effective understanding of the fate and behaviour of organic contaminants in the soil can help determine the persistence of the contaminant in the terrestrial environment, promote the success of any bioremediation approach and help develop a high–level of risks mitigation strategies. In this review paper, we provide a clear insight into the role of plants and microbes in the microbial degradation of petroleum hydrocarbons in contaminated soil that have emerged from the growing body of bioremediation research and its applications in practice. In addition, plant–microbe interactions have been discussed with respect to biodegradation of petroleum hydrocarbons and these could provide a better understanding of some important factors necessary for development of in situ bioremediation strategies for risks mitigation in petroleum hydrocarbon–contaminated soil.

39 citations

OtherDOI
TL;DR: This paper focuses on the study of the biodegradation of Rubber Pipe Joint Rings by microorganisms and biotechnological applications.
Abstract: Introduction Historical Outline General Considerations Early Investigations on the Biodegradation of Natural Rubber Biodegradation of Rubber Pipe Joint Rings Degradation by Fungi Recent Developments Investigations in the Authors' Laboratory Conclusions Microorganisms Capable of Rubber Biodegradation Actinomycetes Microorganisms Other than Actinomycetes Optimization of Rubber Biodegradation Previous Experiences Recent Efforts Enzymatic Mechanisms and Genetic Basis Primary Degradation Reaction for cis-1,4-Polyisoprene Analogous Degradation Known from Other Isoprenoids Catabolism of Rubber Degradation Products Recent Investigations in the Authors' Laboratory Biodegradation of Synthetic Rubbers Biodegradation of trans-1,4-Polyisoprene Anaerobic Biodegradation of cis-1,4-Polyisoprene Perspectives and Biotechnological Applications Acknowledgements Keywords: Actinomycetes; bacteria; biodegradation; biodeterioration; cis-1,4-polyisoprene; carotenoids; classification; dioxygenase; fungi; isoprene rubber; isoprenoids; latex; latex gloves; lignostilbene; microbial degradation; microorganisms; natural rubber; optimization; oxidative cleavage; oxygenase; pipe-joint rings; polyisoprene; rubber degradation; rubber hydrocarbon; rubber polymer; rubber recycling; synthetic rubbers; taxonomy; Actinomyces; Aspergillus; Cladosporium; Fusarium; Gordonia; Micromonospora; Mycobacterium; Nocardia; Penicillium; Proactinomyces; Pseudomonas; Streptomyces; Xanthomonas

38 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20241
202366
2022153
202172
202068
201962