Production and biochemical characterization of polyphenol oxidase from thermomyces lanuginosus

Astarcı, Erhan
Polyphenol oxidases are enzymes that catalyze the oxidation of certain phenolic substrates to quinones in the presence of molecular oxygen. Polyphenol oxidases are widely used in several applications. In food industry, they are used for enhancement of flavor in coffee, tea and cocoa production, and determination of food quality. In medicine, they have several uses in treatments of Parkinson̕s disease, phenlyketonurea and leukemia. In wastewater treatment, they are used for the removal of phenolic pollutants from wastewaters. In pharmaceutical industry, differentiation of morphine from codeine is possible by means of polyphenol oxidase immobilized electrodes. In this study, a thermophilic fungus, Thermomyces lanuginosus was evaluated in terms of poyphenol oxidase production. The effect of different nutrient sources, inducers and fermentation parameters on enzyme production were investigated and maximum PPO activity of 97 U/ml was observed in bioreactor experiments at 50°C, 400 rpm and pH 8.0 in a fermentation medium containing 1.4% yeast extract, 0.3% MgSO4, 1% KH2PO4, 0.003% CuSO4, 0.032% gallic acid. Type of polyphenol oxidase produced by Thermomyces lanuginosus was determined as laccase. For biochemical characterization studies, the enzyme was enriched by electrophoresis. Temperature and pH optima for the enzyme were determined as 60°C and 8.0, respectively. Enzyme retained 67% activity after 1 h incubation at 80°C and retained 87% of its activity after 1 hour of incubation at pH 9.0 at room temperature. The enzyme obeys Michealis-Menten kinetics with Km and Vmax values being 5 mg /ml catechol and 38 U/ml, respectively. Molecular weight of the enzyme was determined as 29 kDa and isoelectric point of enzyme was found to be approximately 6.0.


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Electrochemically produced graft copolymers of thiophene capped polytetrahydofuran (TPTHF1 and TPTHF2) and pyrrole were achieved by constant potential electrolysis using sodium dodecylsulfate (SDS) as the supporting electrolyte. Characterizations were based on Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). Electrical conductivities were measured by the four-probe technique.
Enzyme electrodes fabricated by dad type poly (2,5-di(furan-2-yl)thiazolo[5,4-d]thiazole) conducting polymer
Kurzama, Nadia; Söylemez, Saniye; Böyükbayram, Ayşe Elif; Toppare, Levent Kamil (2020-03-20)
Poly(2,5-di(furan-2-yl)thiazolo[5,4-d]thiazol) polymer was coated over a platinum electrode and new enzyme electrodeswere produced that are not found in the literature. The formation of polymerization was shown by cyclic voltammetry.Kinetic parameters of immobilized polyphenol oxidase enzyme were determined. Vmax and Km were obtained as 0.028 ±0.001 umol min1- electrode1- and 669.68 ± 64.73 mM respectively. The effect of reaction conditions over enzyme activitywere examined. The pH and temperature at which ...
MELLATI, AA; YUCEL, M; ALTINORS, N; Gündüz, Ufuk (1993-10-01)
The M2-type pyruvate kinase was purified from human meningioma by ammonium sulfate precipitation, followed by ion exchange and affinity chromatography. The specific activity of the purified enzyme was 33.4 U/mg with a yield of 6.5%.
Preparation and Characterization of Amino-Functionalized Zeolite/SiO2 Materials for Trypsin-Chymotrypsin Co-immobilization
Dogan, Demet; Sezer, Selda; Ulu, Ahmet; KÖYTEPE, SÜLEYMAN; ATEŞ, BURHAN (2021-08-01)
Inorganic supports have attracted increased attention in enzyme immobilization since they not only improve enzyme stability but also reduce the final cost of enzymatic reactions. Herein, we explored the suitability of the amino-functionalized zeolite/SiO2 materials to co-immobilize trypsin-chymotrypsin mixture. For this purpose, the trypsin-chymotrypsin mixture was co-immobilized on the amino-functionalized zeolite/SiO2 materials and the immobilization yield was 80.7 +/- 7.6%. The pre-support and its modifi...
Synthesis and characterization of conducting copolymers of succinic acid bis-(4-pyrrol-1-yl-phenyl) ester and their electrochromic properties
Ertas, M; Çırpan, Ali; Toppare, Levent Kamil (Elsevier BV, 2004-05-07)
A new dipyrrolyl monomer was synthesized via the reaction between 4-pyrrol-1-yl phenol and butanedioyl dichloride. Electrochemical behavior of this monomer, succinic acid bis-(4-pyrrol-1-yl-phenyl) ester (SM) was studied. Homopolymerization was achieved by chemical and constant Current electrolysis methods. Copolymerization of SM with thiophene was performed by constant potential electrolysis in acetonitrile (AN)-tetrabutylammonium tetrafluoroborate (TBAFB) and dichloromethane (DCM)-TBAFB, solvent-electroly...
Citation Formats
E. Astarcı, “Production and biochemical characterization of polyphenol oxidase from thermomyces lanuginosus,” M.S. - Master of Science, Middle East Technical University, 2003.