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Search Results: 1 - 10 of 915 matches for " Biodegradation "
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Biodegradable and bioactive porous polyurethanes scaffolds for bone tissue engineering  [PDF]
Mei-Na Huang, Yuan-Liang Wang, Yan-Feng Luo
Journal of Biomedical Science and Engineering (JBiSE) , 2009, DOI: 10.4236/jbise.2009.21007
Abstract: Biodegradable porous polyurethanes scaffold have themselves opportunities in service, in-cluding controlled degradation rate, no-toxic degradation products. However, polyurethanes are lack of bioactive groups, which limits their application. This review gives the common modification methods, surface functionalization and blending modification. In finally, the review puts forward to the bulk modification as a new method to enhance the bioactivity of polyure-thanes.
Genome Shuffling of Pseudomonas Sp. Ioca11 for Improving Degradation of Polycyclic Aromatic Hydrocarbons  [PDF]
Manoj Kumar, Mahendra Pratap Singh, Deepak Kumar Tuli
Advances in Microbiology (AiM) , 2012, DOI: 10.4236/aim.2012.21004
Abstract: A Pseudomonas sp. strain IOCa11 exhibiting broad substrate profile for polycyclic aromatic hydrocarbons (PAHs) degradation was isolated by enrichment techniques from oil-contaminated soil. We applied genome shuffling of Pseudomonas sp. strain IOCa11 to achieve improved degradation of PAHs. The initial mutant population was generated by nitrosoguanidine treatment and population exhibiting improved phenotype was subjected to multiple round of protoplast fusion in order to allow recombination between genomes. Mutant, designated as SF-IOC11-16A, obtained after recursive protoplast fusion showed substantial improvement in ability to degrade PAHs in liquid media. It could degrade 98% DBT in 72 hours in comparison to 74% by the wild parent strain. Similar improvement in degradation of the naphthalene (NAP), phenanthrene (PHE), and benzo (α) pyrene (BAP) was also observed in shuffled strain. The shuffled strain was also able to grow at higher concentration of PAHs and degrade them efficiently. The results indicate that genome shuffling can successfully be used to improve the PAHs degradation capability of bacteria.
In-Situ Biostimulatory Effect of Selected Organic Wastes on Bacterial Atrazine Biodegradation  [PDF]
Ahmed Faruk Umar, Fatimah Tahir, Michael Larkin, Olubukola Mojisola Oyawoye, Balarabe Lawal Musa, Mohammed Bello Yerima, Ediga Bede Agbo
Advances in Microbiology (AiM) , 2012, DOI: 10.4236/aim.2012.24076

The biostimulatory effect of selected organic wastes on bacterial biodegradation of atrazine (2-chloro-4-ethylamino-6-isopropylamino-1,3,5-triazine) in three agricultural soils in Bauchi state, Nigeria, was carried out. The soil physico-chemical characteristics were investigated to further understand the environmental conditions of the sampling sites. Enrichment technique was used to isolate the atrazine-degrading strains. Mineralization studies were carried out to determine atrazine biodegradation potentials of strains. Polymerase Chain Reaction (PCR) amplification of total nucleic acid of strains revealed several bacterial species based on nucleotide sequence analyses. Biostimulatory effect of selected organic wastes carried out showed minimal to average extent of biodegradation. The highest mean values, in CFU/mL, increase in biomass was recorded in Pseudomonas sp for both Cow dung 16.76 (42.03%) and Chicken droppings 12.32 (38.46%). However, biostimulatory effect using consortia provided more promising results, with 41.51% and 42.08% in Cow dung and Chicken droppings, biomass increase, respectively, in studies conducted. This proves that competition, survival of inoculums, bioavailability of organic amendments and nature of chemical are important factors affecting bioremediation.

Evidence of Fungicides Degradation by Rhizobia  [PDF]
Hassan Moawad, Wafaa M. Abd El-Rahim, Haitham Shawky, Aziz M. Higazy, Zakaria Y. Daw
Agricultural Sciences (AS) , 2014, DOI: 10.4236/as.2014.57065

Fungicides which are not easily degradable have the greatest adverse effects on soil microbes. These pesticides negatively affect the growth and multiplication of fungi and bacteria and consequently cause the disturbance of the natural soil microbial balance. In this study two fungicide tolerant isolates of rhizobia; clover isolate (TA1) and peanut isolate (8) were assessed in their capacity to degrade Vitavax and Rizolex. The performance of these isolates in fungicides degradation was tested using the colorimetric assay for Rizolex and the HPLC analysis for Vitavax to detect the degradation products. Using HPLC analyses, the control sample showed specific peak indicating the Vitavax presence in the medium. The specific peak did not change in the control samples throughout the experiment.With the strainTA1 the specific peak of the Vitavax fungicides started to reduce as the incubation time goes on. The Vitavax fungicide did not degrade completely after 240 hours of incubation with rhizobial isolate. The Rizolex used in this study contained blend of Thiram (active ingredient of Rizolex) and Tolcofs methyl fungicides in 1:1 ratio. The biodegradation of Rizolex in the liquid media showed the formation of two new intermediates which were released into the medium indicating the degradation of the tested fungicide by peanut rhizobial isolate No. 8 in 48 hrs of incubation 45% of this compound was degraded. This work shows that the selection of fungicides tolerant rhizobial strains is important to protect the rhizobial inoculants from the toxic effect of the pesticides.

Polyurethane as substrate for fungal strains  [PDF]
Araceli Loredo-Trevi?o, Gilberto García, Abraham Velasco-Téllez, Raúl Rodríguez-Herrera, Cristóbal N. Aguilar
Advances in Bioscience and Biotechnology (ABB) , 2011, DOI: 10.4236/abb.2011.22009
Abstract: Polyurethane is a versatile plastic with several industrial applications in the modern life, but it is considered as a very recalcitrant material. Biodegradation of this plastic has been poorly explored, and most of the studies that have been published focus on bacterial enzymes. In this work, some fungi with the capacity of growing with polyurethane foam as nutrient source were isolated from sands contaminated with this plastic and from DIA/UAdeC collection, testing their ability to grow on polyurethane as sole carbon and nitrogen sources and their enzymatic activities were determined in specific media as well as their invasion capacity on polyurethane agar plates. 22 fungal strains demonstrated their capacity of growing on polyurethane. Among the enzymatic activities evaluate, the most common was the urease activity (95% of the strains).Protease, esterase and laccase activities were present in 86%, 50% and 36% respectively. The great ability of the isolated fungal strains to use polyurethane foam as nutrient opens an important opportunity to study at detail the biodegradation of this plastic, with clear implications in cell biology and environmental technology.
Effect of Lauroyl Glutamine on Biodegradation of Lubricating Oil and Simulation of Biodegradation Kinetics  [PDF]
Boshui Chen, Jiang Wu, Jianhua Fang, Weijiu Huang, Jiu Wang
Engineering (ENG) , 2010, DOI: 10.4236/eng.2010.211116
Abstract: Small amount of lauroyl glutamine was incorporated into HVI 350 mineral lubricating oil and the biodegradabilities of neat oil and the formulated oil in soils were evaluated. Thereafter, the biodegradation rate equations for the two lubricating oils were simulated based on the exponential model. The results indicated that lauroyl glutamine effectively promoted biodegradation of HVI 350 mineral lubricating oil. Under given test conditions, the exponential model well fitted the biodegradation of lubricating oils in soils. The biodegradation rate equation for HVI 350 mineral lubricating oil can be described as ln(St/S0) = –0.0155t, while that for the oil formulated with lauroyl glutamine as ln(St/S0) = –0.0235t. The biodegradation half-lives of neat oil and the formulated oils were 44.72 days and 29.50 days, respectively.
Biodegradation of Tritium Labeled Polychlorinated Biphenyls (PCBS) by Local Salt Tolerant Mesophylic Bacillus Strains  [PDF]
Rasulov Bakhtiyor Abdughafurovich, Kim Andrey Andreevich, Lorenz Adrian, Yadgarov Khojiakbar Tashpulatovich
Journal of Environmental Protection (JEP) , 2010, DOI: 10.4236/jep.2010.14048
Abstract: Salt-resistant Bacillus strains, isolated from agricultural soils in Uzbekistan, were tested for degradation activity towards a mixture of polychlorinated biphenyls (PCBs) under aerobic conditions. The study employed the use of tritium labeled PCB congeners and traced the tritium label in cultures with high salt content. The experiments show that most of the selected strains were able to adsorb a part of the radioactivity, indicating transformation of the added PCBs. Gas chromatography demonstrated transformation of PCBs. The radioactive label was removed from several cultures by up to 91%, indicating also mineralization of PCBs. The study suggests that the isolated strains might be good candidates for the bioremediation of contaminated high-salt soils in Uzbekistan and other Central-Asian countries.
Influence of detergent on metabolic activity of fungi Aspergillus niger  [PDF]
Jelica Stojanovi?, Violeta Jakovljevi?, Ivana Matovi?, Olgica Gajovi?, Zoran Miju?kovi?, Tomislav Nedeljkovi?
Natural Science (NS) , 2011, DOI: 10.4236/ns.2011.36064
Abstract: The aim of this study was to find out, among grate variety of fungi species from wastewater these which are resistant to effects of detergent and its component, ethoxyl-oleyl-cetyl alcohol and sodium tripolyphosphate. On inoculated fungi specie grown in vitro condition, in the presence of mentioned pollutant, the metabolic changes of bioproduction of different organic compounds, in various aging step of fungi, have been investigated. The results indicated sig-nificant changes in bioproduction of amino ac-ids and proteins of Aspergillus niger cultivated in the presence of detergent and its component, compared with control experiment. The results suggest that bioremediation by Aspergillus ni-ger are promising for biodegradation of deter-gents in aquatic systems.
(2-Hydroxyethyl)ammonium Lactates—Highly Biodegradable and Essentially Non-Toxic Ionic Liquids  [PDF]
Sanita Pavlovica, Andris Zicmanis, Elina Gzibovska, Maris Klavins, Peteris Mekss
Green and Sustainable Chemistry (GSC) , 2011, DOI: 10.4236/gsc.2011.13017
Abstract: (2-Hydroxyethyl)ammonium lactates have been prepared by reactions of the corresponding (2-hydroxyethyl) amines with lactic acid and characterized by their 1H NMR, IR, and mass spectra. They have been quantita- tively analyzed by HPLC, and their water contents have been determined by the Karl-Fischer method. The title salts are low-melting solids or viscous liquids, and they belong to the class of polar, hydrophilic ionic liquids. The toxicity and chemical and biological degradation of the synthesized ionic liquids have been evaluated by methods described in European Standards. The measurements showed these ionic liquids to be highly biodegradable and only slightly toxic substances. Condensation reactions of benzaldehyde with ethyl cyanoacetate and with acetophenone have been performed in these materials as solvents. The possibility of simultaneously applying these ionic liquids as both solvents and catalysts for the mentioned reactions has been demonstrated, as well as repeated use of the same ionic liquid for a number of condensation reactions without any purification.
Bacterial Influence on Textile Wastewater Decolorization  [PDF]
Aamr Alalewi, Cuiling Jiang
Journal of Environmental Protection (JEP) , 2012, DOI: 10.4236/jep.2012.328104
Abstract: The study aims to isolate and optimize bacterial strains having the ability to degrade and decolorize azo dyes produced in the final effluent of textile dying industries. In this regard, ten bacterial strains were isolated from wastewater treatment plants, and most of them were subjected to the colored effluents resulting from dilapidated houses. The ability of these bacterial isolations to use a wide range of azo dyes to determine the sole carbon source was determined. According to these screening testes, two bacterial isolations were selected as the most potent decolorizer for azo dyes, and they were identified as Comamanas acidovorns-TN1 and Burkholdera cepace-TN5. The optimization process started with the addition of 1 g/l yeast extract, where the decolorization ability of the two strains increased sharply and according to this experiment, the two azo dyes, Acid orange 7 and Direct blue 75, were selected to complete the study. The effect of different conditional and chemical factors on the decolorization process of Acid orange 7 and Direct blue 75 by Comamanas acidovorns-TN1 and Burkholdera cepace-TN5 was studied. Factors that contributed to the difference were different pH, temperature, incubation period, inoculum size, carbon source, nitrogen source and the respective concentrations of yeast extract. This study recommends the application of the two most potent bacterial strains in the decolorization of the azo dyes, along with acid orange 7 and direct blue 75, specifically in the industrial effluents under all nutritional and environmental conditions.
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