Topic
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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TL;DR: In this paper, the microbial communities and functions in impoundments that collected wastewaters from dozens of wells were characterized, and the results showed that microbial richness and diversity were significantly increased in sludge compared with those in hydraulic fracturing (HF) reserves.
12 citations
01 Jan 2021
TL;DR: In addition to the traditional physical and chemical degradation methods, the microbial degradation method is commonly more efficient and low-cost method used for pesticide degradation as discussed by the authors, in which the microbes that demolish these pesticides use the pesticides as nutrients and break them down into tiny nontoxic molecules.
Abstract: Various pesticides including organochlorines, organophosphates, carbamate, pyrethroids, chloronicotinyl etc., are used in agriculture for protection against plant diseases and insects. Only a fraction of the applied pesticides is utilized in killing of target pests and the leftover residual pesticides either remains associated with cereal grains, vegetables, and fruits or may cause environmental pollution. In addition to the traditional physical and chemical degradation methods, the microbial degradation method is commonly more efficient and low-cost method used for pesticide degradation. Microorganisms have been characterized which have the capability to degrade residual pesticides. The microbes that demolish these pesticides use the pesticides as nutrients and break them down into tiny nontoxic molecules. Pesticide degrading microbes belong to different microbial groups, i.e., bacteria, fungi, actinomycetes, and algae. Bacteria possessing pesticide degradation capability include Pseudomonas spp., Bacillus spp., Burkholderia, Klebsiella spp., Streptomyces, etc. and the fungi include Trichoderma spp., Aspergillus spp., Phanerochaete chrysosporium, white rot fungi, etc., whereas algae include Chlamydomonas and marine Chlorella. Major reactions in pesticide destruction include mineralization and co-metabolism. Pesticide degradation is influenced by many factors such as type of pesticide, type of microorganism, temperature, humidity, and acidity in the environment. Plasmid-located genes usually encode many enzymes and degrade a large number of pesticides. Microorganisms may acquire pesticide-degradation capabilities in soil through horizontal gene transfer from degradative plasmids, by modification of substrate specificity, or through altered regulation of preexisting enzymes. With the progress of molecular biology, the genetically engineered rhizobacteria may be built to enhance the bioremediation of pollutants and pesticides. Such recombinant microbial populations may be of immense value in bioremediation of diverse pesticides from the surroundings.
12 citations
TL;DR: In this article, the authors applied microbial soil sanitation technology to calcareous, alkaline, sandy loam soil, polluted with a mixture of hexachlorocyclohexane isomers (alpha 400, beta 230, gamma 15 and delta 17 mg·kg −1 ).
12 citations
TL;DR: The proposed approach can provide a reliable prediction of HC depletion in subsoil on the basis of field measurements and is expected to incorporate into a multiphase flow and multicomponent transport model for application to actual HC-contaminated sites.
Abstract: A new approach was applied to represent the natural attenuation of hydrocarbon (HC) contaminants as observed in a field lysimeter experiment. The approach describes the microbial growth on HC contaminants and linked HC biodegradation under natural precipitation conditions. The HC contaminants contained an inert component (n-dodecane) and soluble components (toluene, ethylbenzene, xylene isomers, and naphthalene), and their attenuation processes were predicted. The respiratory quinone profile method is used to indicate temporary changes in in situ microbial biomass possessed by HC-degrading microorganisms in soils. On the basis of field measurements conducted during the initial 92 days post-HC contamination, the kinetic parameters of HC-degrading microorganisms were estimated, which were used for the prediction of microbial growth and linked HC-contaminant depletion in the contaminated soil for the subsequent 259 days. The prediction was in good agreement with the measured HC concentration and corresponding respiratory quinones from HC-degrading microorganisms. The results indicate that the proposed approach can provide a reliable prediction of HC depletion in subsoil on the basis of field measurements. Further efforts are expected to incorporate the approach into a multiphase flow and multicomponent transport model for application to actual HC-contaminated sites.
12 citations
01 Jan 2013
TL;DR: In this paper, the degradation of polyethylene/starch film has been analyzed by scanning electron microscopy (SEM) before and after degradation, and the results showed that bacteria (Pseudomonas spp, Streptococcus splasmin, Staphylococcus Spla, Micrococcus spp and Moraxella spla), and Actinomycetes are present on the surface.
Abstract: Low density polyethylene is a vital cause of environmental pollution. It occurs by choking sewer line through mishandling thus posing an everlasting ecological threat. Biodegradable plastics are eco-friendly; they accumulate great potential applications in various industries. Biodegradable polymers degrade upon disposal by the action of active microorganisms in the soil. The result of degradation can be interpreted with physical changes through biological force. Microbial degradation of plastics convert polymer into oligomers and monomers. This microbial degradation may be based on aerobic and anaerobic metabolisms. The main objective of present study is to isolate and identify the microorganisms from soil during biodegradation testing of polyethylene/starch film. The isolation is been carried out through soil serial dilution method. An isolated microorganism is cultivated in culture media. After growth of microorganisms at 37 0 C identification of microorganisms was carried out by macroscopic/microscopic examination. During identification it is found that bacteria (Pseudomonas spp, Streptococcus spp, Staphylococcus spp, Micrococcus spp and Moraxella spp etc), fungi (Aspergillus niger, Aspergillus glaucus etc), and Actinomycetes are present on the surface of polyethylene/starch film. Surface morphology of polyethylene/starch film has been analyzed by scanning electron microscopy (SEM) before and after degradation. Physico - mechanical properties has also been determined before and after degradation of film in order to understand the rate as well as the mechanism of degradation.
12 citations