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Time course of epoxyethane production catalyzed by whole cell suspension of Methylosinus trichosporium IMV 3011. Initial concentration of ethylene, oxygen, and nitrogen was 20%, 50%, and 30%, respectively.
Source publication
Methane monooxygenase (MMO) has been found in methanotrophic bacteria, which catalyzes the epoxidation of gaseous alkenes to their corresponding epoxides. The whole cell suspension of Methylosinus trichosporium IMV 3011 was used to produce epoxyethane from ethylene. The optimal reaction time and initial ethylene concentration for ethylene epoxidati...
Citations
... MMO has been found to catalyze the epoxidation of gaseous alkenes to their corresponding epoxides (Fig. 2) (Hou, 1984;Xin et al., 2017;Zhang et al., 2008b). The accumulation of propylene oxide from propylene in a gas-solid bioreactor using M. trichosporium OB3b and Methylosinus sp. ...
... In the case of methanol, the maximum production of 6.6 nM epoxyethane occurs with 3 mM methanol. The removal of the product was proposed to overcome the inhibition of epoxyethane formation (Xin et al., 2017). ...
Methane, the predominant element in natural gas and biogas, represents a promising alternative to carbon feedstocks in the biotechnological industry due to its low cost and high abundance. The bioconversion of methane to value-added products can enhance the value of gas and mitigate greenhouse gas emissions. Methanotrophs, methane-utilizing bacteria, can make a significant contribution to the production of various valuable biofuels and chemicals from methane. Type II methanotrophs in comparison with Type I methanotrophs have distinct advantages, including high acetyl-CoA flux and the co-incorporation of two important greenhouse gases (methane and CO2), making it a potential microbial cell-factory platform for methane-derived biomanufacturing. Herein, we review the most recent advances in Type II methanotrophs related to multi-omics studies and metabolic engineering. Representative examples and prospects of metabolic engineering strategies for the production of suitable products are also discussed.
... This technique relies on the capacity of nitrogenase, the N-fixing enzyme, to reduce triple bonded molecules other than N 2 ; thus, acetylene is reduced to ethylene and ethylene concentrations can then be easily measured using a standard gas chromatograph (GC) equipped with a flame ionization detector (Hardy et al. 1968). However, previous work suggests there are challenges to successfully applying the ARA to FLNF, particularly in the rhizosphere (Witty 1979;van Berkum and Bohlool 1980;Boddey 1987;Giller 1987;Smercina et al. 2019). Nitrogenase has a different affinity for acetylene than N 2 , often outcompeting N 2 when in the same system , making measures of acetylene reduction only a proxy for N-fixation rates. ...
... In addition, the measured product of the ARA, ethylene, can be both produced and consumed in soils independent of actual acetylene reduction (van Berkum and Bohlool 1980;Zechmeister-Boltenstern and Smith 1998). Ethylene is a plant hormone with wide-ranging effects and is naturally produced in soils by both plants and bacteria (Witty 1979;Nohrstedt 1983;Wang et al. 2002;Friesen et al. 2011). In fact, a study which added 14 C-labeled acetylene to the headspace of soil core incubations found that only 43% of recovered ethylene carried the label, indicating that over half of the ethylene was produced endogenously by soil organisms (Witty 1979). ...
... Ethylene is a plant hormone with wide-ranging effects and is naturally produced in soils by both plants and bacteria (Witty 1979;Nohrstedt 1983;Wang et al. 2002;Friesen et al. 2011). In fact, a study which added 14 C-labeled acetylene to the headspace of soil core incubations found that only 43% of recovered ethylene carried the label, indicating that over half of the ethylene was produced endogenously by soil organisms (Witty 1979). Methanogenic bacteria have been shown to oxidize ethylene via the enzyme methane monooxygenase (de Bont 1976;Boddey 1987;Xin et al. 2017) and though few recent studies have been published on the topic, our calculations of Gibb's free energy for the oxidation of ethylene to ethylene oxide reveal a favorable and spontaneous reaction at room temperature (ΔG°= −81.4 kJ mol −1 ). ...
Aims
To optimize assay conditions of two common methods for measuring potential free-living nitrogen-fixation (FLNF), acetylene reduction assay (ARA) and ¹⁵N2-incorporation (¹⁵N2), for use with soil/rhizosphere samples.
Methods
We tested the impact of different carbon (C) sources, oxygen concentrations (O2), and incubation times on FLNF rates of two low-fertility Michigan soils via ARA and ¹⁵N2.
Results
FLNF rates were greatest with addition of a C cocktail, at low O2, and with 7-day incubations for both methods. FLNF via ARA was 1700x greater with a C cocktail versus glucose only and via ¹⁵N2 was 17x greater with a C cocktail compared to other C sources and no-C controls. Specific O2 optimum varied by method and site. A 7-day incubation was needed for the ARA, but a 3-day incubation was suitable for ¹⁵N2. Lastly, we confirm previously identified issues with the ARA of acetylene-independent ethylene production/consumption resulting in potential FLNF measurement error of 1.3–52.3 μg N g⁻¹ day⁻¹.
Conclusions
We present an optimized method for measuring potential FLNF in soil/rhizosphere samples which will allow for consistent and comparable FLNF rate measurements. Researchers should account for C source, O2, and incubation time when assessing FLNF and use the ARA method with caution.
... It is also involved in a cascade reaction along with a ketoreductase and produced epoxy ketones and allylic epoxy alcohols with >99% ee and is also a subject of protein engineering studies which are underway (Liu et al. 2016). Another whole cell suspension of Methylosinus trichosporium IMV 3011 containing methane monooxygenase biosynthesize epoxyethane (6.6 n mol) from ethylene which is a useful and important intermediate for industrial chemical production (Xin et al. 2017). A recombinant engineered toluene o-xylene monooxygenase from Burkholderia cepacia G4 carried out industrially significant oxidation of ethylene to ethylene oxide by >5500-fold relative to the native enzyme (Carlin et al. 2015). ...
This book presents the complete guide for readers to understand the applications, and pros and cons of nanotechnology applications in environmental remediation, although there are few critical reviews and textbooks available on environmental biotechnology. Water pollution has become one of the biggest concerns of the world. After the industrialisation and urbanisation, environmental pollution has become an enormous concern. Water pollution results in biomagnifications by entering the food chain. As a result water pollution and its risks need to be considered seriously and solutions need to be researched. This volume looks into such topics as bioremediation, nanobiotechnology, biosensors, and enzyme degradation to find solutions to these problems.
... Fe [77] and Mo complexes [78] supported on modified halloysite nanotubes allowed to selectively epoxidize both cyclic and linear alkenes. Fe catalyst appeared here as complex with anionic porphyrin, containing SO 3 − groups, easily forming hydrogen bonds, while the immobilization process was performed by hydrothermal method, using precalcinated (so called "meta") halloysite as a support. ...
... Herein, Fe-Por/HNT nanocomposite, combined with PhIO as an oxidant, gave epoxide yield of 85% after 1 h at room temperature, which is highly efficient when compared to other homogeneous molecular catalysts [77]. In the case of Mo-salen/HNT catalyst, with tert-butylhydroperoxide (THBP) as an oxidant, both temperature and reaction time were dependent on size and shape of the substrate (longer linear alkenes and styrene required higher temperatures and longer reaction time for effective reaction proceeding) [78] that could be attributed to the substrate-selective properties of halloysite nanotubes. Herein both Fe and Mo nanocomposite catalysts were recycled several times without significant loss of their activity and selectivity [69]. ...
... The epoxidation reaction order at each temperature and type of catalyst is a pseudofisrt order. This is in line with the research [11]. ...
This research aimed at studying the effect of reaction time, temperature and the type of catalyst on oxirane number and determining reaction kinetics data. There were two types of catalysts used were bentonite and sulfuric acid (H2SO4). The epoxidation reaction was done in-situ using hydrogen peroxide, acetic acid and benzene with bentonite and H2SO4 into the RBD palm olein to form epoxidized RBD palm olein. The main equipment used in this research was a 500 mL three-necked flask, equipped with a reflux condeser, thermometer, water bath and magnetic stirrer. The product was analysed of % of oxirane using a titration method. The results of this research showd that bentonite catalysts was optimally working at the temperature of 70?C for 4 hours with an oxirane level of 1.02%, while H2SO4 was optimally working at the temperature of 60?C for 3 hours with oxirane level of 2.31%.
Since the racemic enantiomers have different physiologic effects, there are strong recommendations by US FDA for the production of chiral drugs, and since then the chiral drug industry has been growing with 15% growth rate projected for the period 2010–2022. For the synthesis of chiral drugs, enantiopure epoxides and diols serve as important precursors. Though several chemo-catalytic strategies have been employed for their production, nowadays due to a rising environmental concern, there is an upsurge in the development of greener technologies for the production of chiral drugs. Thus, biocatalysis appears as a green alternative.
