title: Comparative enzyme inhibitive methanol production by Methylosinus sporium from simulated biogas.
abstract: Methane in a simulated biogas converting to methanol under aerobic condition was comparatively assessed by inhibiting the activity of methanol dehydrogenase (MDH) of Methylosinus sporium using phosphate, NaCl, NH4Cl or EDTA in their varying concentrations. The highest amount of methane was indistinguishably diverted at the typical conditions regardless of the types of inhibitors: 35°C and pH 7 under a 0.4% (v/v) of biogas, specifically for <40 mM phosphate, 50 mM NaCl, 40 mM NH4Cl or 150 µM EDTA. The highest level of methanol was obtained for the addition of 40 mM phosphate, 100 mM NaCl, 40 mM NH4Cl or 50 µM EDTA. In other words, 0.71, 0.60, 0.66 and 0.66 mmol methanol was correspondingly generated by the oxidation of 1.3, 0.67, 0.74 and 1.3 mmol methane. It gave a methanol conversion rate of 54.7%, 89.9%, 89.6% and 47.8%, respectively. Among them, the maximum rate of methanol production was observed at 6.25 µmol/mg h for 100 mM NaCl. Regardless of types or concentrations of inhibitors differently used, methanol production could be nonetheless identically maximized when the MDH activity was limitedly hampered by up to 35%.
authors.affiliation: a Department of Environmental Engineering , Inha University , Incheon , Republic of Korea.
authors.forename: Yeon-Sun
authors.initials: YS
authors.lastname: Yoo
authors.forename: Ji-Sun
authors.initials: JS
authors.lastname: Han
authors.forename: Chang-Min
authors.initials: CM
authors.lastname: Ahn
authors.forename: Chang-Gyun
authors.initials: CG
authors.lastname: Kim
mesh_terms: D000429:Alcohol Oxidoreductases / Q000037:antagonists & inhibitors*; D000643:Ammonium Chloride / Q000737:chemistry; D056804:Biofuels; D004492:Edetic Acid / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D000432:Methanol / Q000378:metabolism*; D020581:Methylosinus / Q000201:enzymology*; D010084:Oxidation-Reduction; D012965:Sodium Chloride / Q000737:chemistry; D013696:Temperature
chemical_list: D056804:Biofuels; D000643:Ammonium Chloride; D012965:Sodium Chloride; D004492:Edetic Acid; D000429:Alcohol Oxidoreductases; C019641:alcohol dehydrogenase (acceptor); D000432:Methanol
keywords: Methylosinus sporium; biogas; methane monooxygenase (MMO); methanol; methanol dehydrogenase (MDH); methanotrophs