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Animal and Municipal Organic Wastes and Water Quality
Published in R. Lal, B. A. Stewart, Soil Processes and Water Quality, 2020
Fertilization with fresh poultry manure resulted in a rapid increase in inorganic N in soil within 2 weeks after the addition, amounting to more than 50% of the total N present (Castellanos and Pratt, 1981; Hadas et al., 1983; Gale and Gilmour, 1986; van Fassen and van Dijk, 1987; Bitzer and Sims, 1988; Kirchmann, 1991). As mentioned in Table 2, total nitrogen in fresh poultry excreta consists to more than 50% of uric acid. The fast decomposition of uric acid via urea results in the high release of N from fresh poultry excreta. In soil, the enzyme uricase (urate oxidase) and aerobic microorganisms decompose uric acid and urates (Bachrach, 1957; Durand, 1961; Martin-Smith, 1963). Thus, the fertilizer effect of this type of manure is closest to that of inorganic N. N mineralization from fresh beef and swine manure was found to be much lower than from fresh poultry manure, being lowest for fresh beef manure (Reddy et al., 1980; Kirchmann, 1991).
Nanozymes and Their Applications in Biomedicine
Published in Klaus D. Sattler, st Century Nanoscience – A Handbook, 2020
Qian Liang, Ruofei Zhang, Xiyun Yan, Kelong Fan
The nanozymes mentioned above can be assembled together to form complexes of integrated nanozymes with multiple enzyme-like catalytic activities. Glucose oxidase (GOx)@zif-8 (Ni/Pd) exhibits both the peroxidase-like activity of Ni/Pd NPs and the catalytic activity of the coupled natural glucose oxidase (Qingqing Wang 2017). Rationally designed multiple nanozyme complexes could also catalyze enzyme cascade reactions (Hanjun Cheng 2016, Minfeng Huo 2017, Qingqing Wang 2017, Secheon Jung 2017). For example, Au nanozyme combined with urate oxidase could initiate a one-pot enzyme–nanozyme cascade reaction, which could be used in the treatment of hyperuricemia (Secheon Jung 2017). In this cascade reaction, uric acid oxidase degrades uric acid caused by hyperuricemia, and then the resulting H2O2 could be decomposed by the catalase activity of Au nanozymes. During the whole reaction process, the uric acid is rapidly removed without releasing the damaging H2O2, thus eliminating oxidative damage.
Synthesis of Antioxidants via Biocatalysis
Published in Peter Grunwald, Pharmaceutical Biocatalysis, 2019
Free radicals are generated inside the cells through different pathways as discussed earlier. They cause serious cell injuries. Metal ions, such as iron, catalyze the production of even more free radicals, leading to more cell injuries. Phagocytes are the well-established sources of free radicals. Activated phagocytes are vigorously involved in oxidative burst. The mitochondrial electron transport system is another major source of ROS. This involves the NADH-coenzyme Q, succinate-coenzyme Q, and coenzyme QH2-cytochrome c reductases. The production of ROS by mitochondria is directly linked with oxygen consumption. Oxidases such as, xanthine oxidase, dopamine-b-hydroxylase, urate oxidase, d-amino acid oxidase, and fatty acyl CoA oxidase are also considered to be involved in ROS production.
Characterization of a novel marine microbial uricase from Priestia flexa and evaluation of the effects of CMCS conjugation on its enzymatic properties
Published in Preparative Biochemistry & Biotechnology, 2023
YuLiang Jiao, YuYing Zhu, ShuMin Zeng, ShuFang Wang, Jing Chen, XiangHong Zhou, GuiZhen Ma
Uricase (EC 1.7.3.3), also referred to as urate oxidase, occurring widely in animals and microorganisms, catalyzes the oxidation of uric acid to allantonin, hydrogen peroxide, and carbon dioxide. The enzyme plays a key role in purine metabolism by keeping plasma uric acid at normal levels. In human and other apes, there is only a nonfunctional uricase pseudogen in lieu, which makes the serum uric acid higher in human or these animals than other mammals.[1] The high uric acid levels might contribute to the increase of life expectancy and intelligence of humans in evolution.[1] However, uric acid is a sword with two edges—accumulation of uric acid in excess in serum of humans can cause various diseases including the well-known intolerable arthritis gout, hyperuricemia complicating tumor lysis syndrome and even life-threatening conditions such as acute renal failure.[2]
Optimization of novel and greener approach for the coproduction of uricase and alkaline protease in Bacillus licheniformis by Box–Behnken model
Published in Preparative Biochemistry and Biotechnology, 2018
Shweta V. Pawar, Virendra K. Rathod
Uricase or urate oxidase (EC 1.7.3.3) is an enzyme of purine breakdown pathway, catalyzing the oxidation of uric acid to allantoin and hydrogen peroxide in the presence of oxygen. It can be used medicinally as a diagnostic reagent for measurement of blood uric acid levels, which is a significant application in clinical biochemistry. It is also needed in large quantities as a protein drug to reduce toxic urate accumulation in gout patients.[4] Many organisms, including plants and microorganisms, are able to produce uricase. The enzyme has been purified from leaves of Cicer arietinum L., Vicia faba major L., and Triticum aestivum L.[5] Several literature reports also demonstrated that uricase can be produced by bacteria such as Pseudomonas aeruginosa,[6]Mycobacteria,[7]Gliomastix gueg,[8] and Proteus mirabilis.[9]