Butyrate degradation

During start-up, the microbial population distribution in the biofilm varies with time. Initial colonization of the particle may be by one or more species that alter the surface favorably for colonization by other species. For instance, in the operation of a butyrate-degrading fluidized bed bioreactor, methanogens attached to the sand particles early in the start-up process and produced a primary matrix of heteropolysaccharides that allowed attachment of other bacterial species (Sreekrishnan et al., 1991 Zellner et al., 1991 Yongming et al., 1993). This is contrary to findings in an acetate-propionate-butyrate degrading reactor, in which facultative anaerobes were found to be the initial colonizers (Lauwers et al., 1990). 

Zellner, G., Geveke, M., de Macario, E. C., and Diekmann, H., Population Dynamics of Biofilm Development During Start-Up of a Butyrate-Degrading Fluidized-Bed Reactor, Appl. Microbiol. Biotechnol., 36 404 (1991)... 

Schmidt J. E. and Ahring B. K. (1995) Interspecies electron transfer during propionate and butyrate degradation in mesophilic, granular sludge. Appl. Environ. Microbiol. 61, 2765-2767. 

Tomei FA, Maki JS, Mitchell R (1985) Interactions in syntrophic associations of endospore-forming, butyrate-degrading bacteria and H2-consuming bacteria. Appl Environ Microbiol 50 1244—1250... 

In order to obtain information regarding the composition of these degradation products, aqueous extracts of the lead soaps of the linseed oil fatty acids were analysed, mainly by chromatography. The extracts contained formic acid 46%, azelaic acid 9% and pelargonic acid and its derivatives 27%, the remaining 18% consisting of a mixture of acetic, propionic, butyric, suberic, pimelic and adipic acids. It was shown that whereas the salts of formic acid were corrosive, those of azelaic and pelargonic acid were very efficient inhibitors. 

The solid-state NMR technique may also be used in cellulose derivatives to follow the degree of substitution and degradation of the chain e.g. as found for cellulose nitrate 16). Investigations on the composition of copolymers may also been done as examplared by celluloseacetate-butyrate given in Fig. 6, 20). Here, owing to relaxation differences the spectra cannot be used for elementary analyses, but for estimating the relative number of the components. 

Acid anhydrides have been employed with, and without the use of a base catalyst. For example, acetates, propionates, butyrates, and their mixed esters, DS of 1 to ca. 3, have been obtained by reaction of activated cellulose with the corresponding anhydride, or two anhydrides, starting with the one with the smaller volume. In all cases, the distribution of both ester groups was almost statistic. Activation has been carried out by partial solvent distillation, and later by heat activation, under reduced pressure, of the native cellulose (bagasse, sisal), or the mercerized one (cotton linters). No catalyst has been employed the anhydride/AGU ratio was stoichiometric for microcrystalhne cellulose. Alternatively, 50% excess of anhydride (relative to targeted DS) has been employed for fibrous celluloses. In all cases, polymer degradation was minimum, and functionalization occurs preferentially at Ce ( C NMR spectroscopic analysis [52,56,57]). 

Simoni S, S Klinke, C Zipper, W Angst, H-P E Kohler (1996) Enantioselective metabolism of chiral 3-phenyl-butyric acid, an intermediate of linear alkylbenzene degradation, by Rhodococcus rhodochrous. Appl... 

Reductases play a cardinal role in the anaerobic degradation of diverse aromatic compounds, for example, (a) the reduction of benzoyl-CoA that is a prelude to the fission of the ring (Harwood et al. 1999) (Chapter 8, Part 3) and (b) the degradation of phloroglucinol via dihydrophloroglucinol to acetate and butyrate (Haddock and Ferry 1989, 1993) (Chapter 8, Part 4). 

The fermentation of 3-hydroxybenzoate by Sporotomaculum hydroxybenzoicum produces acetate, butyrate, and CO2, with benzoate as a transient intermediate (Brauman et al. 1998). However, although the degradation of 3-hydroxybenzoate by Thauera aromatica begins with the formation of the CoA-ester, this is followed by the reduction of the ring with retention of the original hydroxyl group (Laempe et al. 2001). 

DIRECT DEGRADATION OF THE BIOPOLYMER P0LY[(R)-3-HYDR0XY-BUTYRIC ACID] TO (R)-3-HYDR0XY-BUTANOIC ACID AND ITS METHYL ESTER... 

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