Methylotrophic Metabolism

Y. (2005) Assimilation, dissimilation, and detoxification of formaldehyde, a central metabolic intermediate of methylotrophic metabolism, Chem. 

Methanotrophic and methylotrophic metabolism may be expanded to include a set of oxidative, hydrolytic or thiolytic reactions whereby simple orgatuc structures can be transformed to the methanotrophic intermediates methanol, formaldehyde. 

A few of the reactions carried out by the monooxygenase system of methanotrophic bacteria are summarized in Figure 2.9, and it is on account of this that methylotrophs have received attention for their technological potential (Lidstrom and Stirling 1990). An equally wide metabolic potential has also been demonstrated for cyclohexane monooxygenase, which has been shown to accomplish two broad types of reaction one in which formally nucleophilic oxygen reacts with the substrate, and... 

Borodina E, Kelly DP, Schumann P, et al. 2002. Enzymes of dimethylsulfone metabolism and the phylogenetic characterization of the facultative methylotrophs Arthrobacter sulfonivorans sp. nov., Arthrobacter methylotrophus sp. nov., and Hyphomicrobium sulfonivorans sp. nov. Arch Microbiol 177 173-83. 

Availability is not the only constraint on substrate consumption. The value of a substrate is also related to the resources needed to convert the molecule into an intermediary metabolite. Thus in aerobic environments, monosaccharides and amino acids are readily consumed under anaerobic conditions, heterotrophic metabolism is largely fueled by small organic acids. Some taxa consume other types of substrates as long as they are reasonably abundant. Important examples include P-proteobacteria that consume phenols, a significant component of DOM inputs originating from plant material, and methylotrophs that consume single carbon compounds produced by anaerobic metabolism, photochemical reactions, and oxidation of methyl and methoxy substituents (Giovannoni and Rappe, 2000). 

Methyloversatilis universalis Methylotroph Label-free Metabolic pathway analysis (192)... 

Different 2H-, 13C- and/or 15N isotopomers of L-serine, [(S)-2-amino-3-hydroxypro-panoic acid], 95, required for studies of aminoacid metabolism and for studies of peptide and protein structure and dynamics, have been biosynthesized stereoselectively84 using the serine-type methylotrophic bacterium, Methylobacteri extorquens AMI, which contains85 large amounts of the enzymes methanol dehydrogenase and hydroxymethyl-transferase (equation 39). 

S. J. van Dien and M. E. Lidstrom. Stoichiometric model for evaluating the metabolic capabilities of the facultative methylotroph methylobacterium extorquens ami, with application to reconstruction of c(3) and c(4) metabolism. Biotechnol. Bioeng., 78 296-312, 2002. 

Methylamine dehydrogenase [MADH] is a periplasmic enzyme which has been purified from several gram negative methylotrophic and autotrophie bacteria (reviewed in Davidson, 1993 Davidson et al, 1995a). It catalyzes the oxidation of methylamine to formaldehyde and ammonia, and in the proeess transfers two electrons from the substrate to some electron acceptor (Eq. 1). This reaetion is the first step in the metabolism of methylamine, whieh ean... 

Colby, J., and Zatman, L. J., 1973, Trimethylamine metabolism in obligate and facultative methylotrophs, Biochem. J. 132 1019112. 

Levering, P. R., van Dijken, J. P., Veenhuis, M., and Harder, W., 1981, Arthrobacter PI, a fast growing versatile methylotroph with amine oxidase as a key enzyme in the metabolism of methylated amines Arch. Microbiol. 129 72980. 

Loginova, N. V., and Trotsenko, Y. A., 1978, Carbon metabolism in methylotrophic bacteria isolated from activated sludge, Mikrobiologiya 47 9399946. 

Methanol dehydrogenase (MDH) enzyme is found in the periplasm of methylotrophic bacteria, and plays a cracial role in the metabolism of these organisms. It catalyzes the oxidation of methanol... 

Beyond metabolism of carbohydrates, there are several other biological processes common in prokaryotes that consume oxygen. For example, methylotrophic organisms can metabolize Ci compounds such as methane, methanol, formaldehyde, and formate, as in... 

Korpan YI, Gonchar MV, Starodub NF, et al. 1993. A cell biosensor specific for formaldehyde based on pH-sensitive transistors coupled to methylotrophic yeast cells with genetically adjusted metabolism. Anal Biochem 215 216-222. 

Bacterial Metabolism of C-l Compounds Methanotrophs, Methylotrophs, and Related Organisms... 

Degradation of the simplest representatives under aerobic conditions has been investigated in the course of comprehensive studies on the metabolic potential of methylotrophic bacteria. These reactions have been admirably summarized in a book (Anthony 1982) to which reference may be made for details. Only two simple examples will therefore be used for illustration ... 

Quinolines play a relatively minor role in fundamental metabolism, methoxatin, an enzyme cofactor of methylotrophic bacteria, being one of the small number of examples. There are also comparitively few quinoline-containing secondary metabolites, in contrast to isoquinoline, which occurs, mainly at the 1,2,3,4-tetrahydro-level, in a large number of alkaloids - the opium poppy alkaloids papaverine and, in more-elaborated form, morphine are examples. Emetine, with two tetrahydroisoquinoline units, is a medicinally important amoebicide. 

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