A modellistic view of the kinetics of metabolic processes: differences in the glucose and xylose degradation pathway

For single-sludge denitrification systems, modelling of anoxic reactors currently uses the kinetics of aerobic heterotrophic growth together with a correction factor for anoxic conditions. This coefficient is computed on the basis of respirometric measurements with the assumption that the heterotrophic yield remains the same under aerobic and anoxic coditions. The paper provides the conceptual proof that the yield coefficient is significantly lower for the anoxic growth on the basis of the energetics of the related metabolic processes. This is used for the interpretation of the very high values for the correction factor experimentally determined for a number of industrial wastewaters. A default value for the anoxic heterotrophic yield coefficient is calculated for domestic sewage and compatible wastewaters and proposed for similar evaluations.

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Mechanism of bio-electrokinetic remediation of pyrene contaminated soil: Effects of an electric field on the degradation pathway and microbial metabolic processes

Journal of Hazardous Materials ◽

10.1016/j.jhazmat.2021.126959 ◽

2021 ◽

pp. 126959

Author(s):

Ruijuan Fan ◽

Haihua Tian ◽

Qiong Wu ◽

Yuanyuan Yi ◽

Xingfu Yan ◽

...

Keyword(s):

Electric Field ◽

Contaminated Soil ◽

Degradation Pathway ◽

Electrokinetic Remediation ◽

Metabolic Processes ◽

Soil Effects

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Photo degradation kinetics of insensitive munitions constituents nitroguanidine, nitrotriazolone, and dinitroanisole in natural waters

10.21079/11681/41900 ◽

2021 ◽

Author(s):

Lee Moores ◽

Stacy Jones ◽

Garrett George ◽

David Henderson ◽

Timothy Schutt

Keyword(s):

Laboratory Experiments ◽

Natural Waters ◽

Matrix Effects ◽

Degradation Kinetics ◽

Relative Rate ◽

Ph Dependence ◽

Degradation Pathway ◽

Quantum Yields ◽

The Individual ◽

Kinetics Of

Herein the matrix effects on the kinetics of aqueous photolysis for the individual munitions constituents of IMX-101: nitroguanidine (NQ), dinitroanisole (DNAN), and nitrotriazolone (NTO) are reported along with the environmentally relevant kinetics and quantum yields. Photolysis potentially represents a major degradation pathway for these munitions in the environment and further understanding the complex matrices effects on photolytic kinetics was needed. Aqueous systems are of particular interest due to the high solubility of NQ (3,800 ppm) and NTO (16,642 ppm) compared to the traditional munitions trinitrotoluene (TNT, 100.5 ppm) and 1,3,5-trinitro-1,3,5-triazine (RDX, 59.9 ppm). Environmental half-lives (and quantum yields) were found to be 0.44 days, 0.83 days, and 4.4 days for NQ, DNAN, and NTO, respectively, under natural sunlight. In laboratory experiments using nominally 300 nm bulbs in a merry-go-round style reactor in DI water the relative rate of photolysis for the three munitions constituents followed the same order NQ > DNAN > NTO, where DNAN and NTO reacted 57 and 115 times more slowly, respectively, than NQ. In the various environmentally relevant matrices tested in the laboratory experiments NQ was not significantly affected, DNAN showed a faster degradation with increasing ionic strength, and NTO showed a modest salinity and pH dependence on its rate of photolysis.

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Modelling Interpretation of the Kinetics of Metabolic Processes

Chemistry at the Beginning of the Third Millennium ◽

10.1007/978-3-662-04154-3_14 ◽

2000 ◽

pp. 305-328 ◽

Cited By ~ 1

Author(s):

S. Bastianoni ◽

C. Bonechi ◽

A. Gastaldelli ◽

S. Martini ◽

C. Rossi

Keyword(s):

Metabolic Processes ◽

Kinetics Of

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Degradation pathway, toxicity and kinetics of 2,4,6-trichlorophenol with different co-substrate by aerobic granules in SBR

Bioresource Technology ◽

10.1016/j.biortech.2011.04.057 ◽

2011 ◽

Vol 102 (13) ◽

pp. 7016-7021 ◽

Cited By ~ 34

Author(s):

Mohammad Zain khan ◽

Pijush Kanti Mondal ◽

Suhail Sabir ◽

Vinod Tare

Keyword(s):

Degradation Pathway ◽

Aerobic Granules ◽

Kinetics Of

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Biochemical and structural characterization ofKlebsiella pneumoniaeoxamate amidohydrolase in the uric acid degradation pathway

Acta Crystallographica Section D Structural Biology ◽

10.1107/s2059798316007099 ◽

2016 ◽

Vol 72 (6) ◽

pp. 808-816 ◽

Cited By ~ 2

Author(s):

Katherine A. Hicks ◽

Steven E. Ealick

Keyword(s):

Uric Acid ◽

Active Site ◽

Degradation Pathway ◽

Α Subunit ◽

Acid Degradation ◽

Substrate Complex ◽

Steady State Kinetics ◽

Biochemical Studies ◽

Kinetics Of ◽

Insight Into

HpxW from the ubiquitous pathogenKlebsiella pneumoniaeis involved in a novel uric acid degradation pathway downstream from the formation of oxalurate. Specifically, HpxW is an oxamate amidohydrolase which catalyzes the conversion of oxamate to oxalate and is a member of the Ntn-hydrolase superfamily. HpxW is autoprocessed from an inactive precursor to form a heterodimer, resulting in a 35.5 kDa α subunit and a 20 kDa β subunit. Here, the structure of HpxW is presented and the substrate complex is modeled. In addition, the steady-state kinetics of this enzyme and two active-site variants were characterized. These structural and biochemical studies provide further insight into this class of enzymes and allow a mechanism for catalysis consistent with other members of the Ntn-hydrolase superfamily to be proposed.

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Degradation Pathway and Kinetics of Vanillin with Gordonia sp.

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.550-553.2824 ◽

2012 ◽

Vol 550-553 ◽

pp. 2824-2827 ◽

Cited By ~ 1

Author(s):

Liping Yao ◽

Wenzhe Song ◽

Yuan Cai Chen

Keyword(s):

Rate Constant ◽

Removal Rate ◽

Degradation Pathway ◽

Spectroscopic Technique ◽

Product Structure ◽

Reaction Pathways ◽

Order Model ◽

First Order ◽

Kinetics Of

This study is to discuss the reaction pathways of vanillin (3-methoxy-4-hydroxy-benzaldehyde) degradation by Gordonia sp.The product structure was analyzed by spectroscopic technique. Vanillin removal kinetics could be best described by a simple recalcitrant first order model:-dS/dt=k s,1 X(S-S∞),k s,1 is the vanillin removal rate constant.

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