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Heavy Metals, Hydrocarbons, Radioactive Materials, Xenobiotics, Pesticides, Hazardous Chemicals, Explosives, Pharmaceutical Waste and Dyes Bioremediation
Published in Vivek Kumar, Rhizomicrobiome Dynamics in Bioremediation, 2021
Elżbieta Wołejko, Agata Jabłońska-Trypuć, Andrzej Butarewicz, Urszula Wydro
Biotransformation of xenobiotics involving microorganisms can occur both in the absence or presence of oxygen (Cao et al. 2009). In most cases, oxygen is involved in the first reactions of xenobiotic transformations, regardless of whether their chemical structure is aromatic or aliphatic (Sinha et al. 2009). However, as suggested by Cao et al. (2009), hydroxylation reactions of these compounds seem to be of key importance in their transformation processes, and sometimes can be the limiting stage for xenobiotics metabolism by microorganisms. The major hydroxylation reactions involve oxygenase enzymes, mainly dioxygenase or monooxygenase (Ullrich and Hofrichter 2007). Moreover, through oxidation of aliphatic xenobiotics, carboxylic acids are formed, which may be the central indirect metabolite participating in the fatty acid transformation cycle in the microbial cell. In turn, the distribution of xenobiotics with an aromatic structure involves the transformation of the xenobiotic to one of the key indirect metabolites, such as procatechuic acid, catechol, hydroquinone or gentisic acid (Cao et al. 2009). Their common feature is the presence of two hydroxyl groups located either in the para or ortho position. If the hydroxyl group is in the structure of the compound which undergoes microbiological biodegradation, monooxygenase involved in the transformation of this compound introduces one of the oxygen atoms into the aromatic ring, which reduces other to water (Ullrich and Hofrichter 2007). Vaillancourt et al. (2006) report that the situation is different when the structure of the aromatic compound has no hydroxyl substituents. Then, it is required to introduce two hydroxyl groups into the ring and this transition is catalysed by hydroxylating dioxygenase.
Thin-Layer Chromatography in Pharmaceutical Analysis
Published in Bernard Fried, Joseph Sherma, Practical Thin-Layer Chromatography, 2017
Elena Dreassi, Giuseppe Ceramelli, Piero Corti
Kincaid et al.64 present a HPTLC method for the determination of salicylates in urines that is more sensitive and selective than Trinder’s test and its modified derivatives commonly used for the screening of salicylate and its metabolites, based on the formation of colored compounds as a reaction to a ferric ion solution under moderate acidic conditions. This highly specific procedure is used in cases where low detection limits and high specificity are required, as in cases of treatment of cardiovascular or cerebrovascular diseases. The initial doses of the main component are low and the quantity of the main component and its metabolites found in the urine is about 2 to 6 mg/l. These properties are indispensable in cases of allergic attacks, asthma, and anaphylactic reactions. Furthermore it could be used for a prescreening of blood donors. The method is based on an analysis on HPTLC silica gel plates, developed with a mobile phase of benzene–acetic acid–diethyl-ether–methanol (60:90:30:0.5, v/v/v/v), after extraction of the urine. After the plates have been dried and an analysis under UV light at 254 nm, the plates are sprayed with 5% aqueous ferric chloride, acidified with chloride acidic 0.05M as chromogen, and observed at 550 nm for confirmation and quantification. Thus it is possible to identify, together with the corresponding Rf: salicilic acid (0.70), diflunisal (0.70), aspirin (ASA)(0.67), methyl salicylate (0.67), gentisic acid (0.60), paraminosalycilic acid (0.57), and salicyuric acid (0.40). The detection limit is 1 ppm or less in comparison with more than 20 ppm for Trinder’s test. Sensitivity is sufficient to give positive test results 48 hours after a single 80-mg dose of ASA by mouth or a 100-mg dose of methyl salicylate by skin injection with a muscle rub, and more than 96 hours after a 660-mg oral aspirin dose.
Identification and characterization of PAH-degrading endophytes isolated from plants growing around a sludge dam
Published in International Journal of Phytoremediation, 2019
Raymond O. Anyasi, Harrison I. Atagana, Rene Sutherland
The catabolism of aromatic compounds using oxygen resulted in three intermediate formations, catechol, protocatechuate, and gentisic acid. These were further metabolized to simple acids and aldehydes that are easily accessible to the microorganism (Al-Wasify and Hamed 2014; Mishra et al.2014; Singh and Chandra 2014; Guo et al.2015). From the result of the assay of the enzyme genes using the appropriate primers, the study was able to establish the presence of these genes in the bacterial isolates, which renders them the ability to catabolize aromatic compounds. This finding is in agreement with that of Guo et al. (2015), which reported that the presence of such genes in bacteria conforms to them the ability to degrade hydrophobic compounds. And in this study, the presence of catechol-1,2-dioxygenase genes in the bacteria isolates enables them to degrade PAHs (Sivaraman et al.2012).
Agromyces and Arthrobacter isolates from surficial sediments of the Passaic River degrade dibenzofuran, dibenzo-p-dioxin and 2-monochlorodibenzo-p-dioxin
Published in Bioremediation Journal, 2021
Haider S. Almnehlawi, Rachel K. Dean, Staci L. Capozzi, Lisa A. Rodenburg, Gerben J. Zylstra, Donna E. Fennell
Pseudomonas strain HH69 was isolated from soil samples by using DF as a sole carbon and energy source. During biodegradation, salicylic acid, gentisic acid and catechol were formed as metabolites. It could metabolize 1 g/L of DF in 120 hrs, and it could be used in pure and mixed cultures (Fortnagel et al. 1990).