Escherichia coli acids

Foster, J.W. (2004) Escherichia coli acid resistance tales of an amateur... 

Miscellaneous Alkaloids. Stukimic acid (57) is a precursor of anthranihc acid (28) and, in yeasts and Escherichia coli (a bacterium), anthranHic acid (o-aminobenzoic acid) is known to serve as a precursor of tryptophan (26). A similar but yet unknown path is presumed to operate in higher plants. Nonetheless, anthranHic acid itself is recognized as a precursor to a number of alkaloids. Thus damascenine [483-64-7] (134), C qH NO, from the seed coats of JSHgella damascena has been shown (95) to incorporate labeled anthranHic acid when unripe seeds of the plant are incubated with labeled precursor. 

Hydroxymethylcytosine (967) was isolated only in 1952 from the T-even bacteriophages of Escherichia coli, in which it occurs instead of cytosine in the 2-deoxyribonucleic acid (65MI21304). Of several syntheses described, the most convenient is probably that beginning with ethyl 4-amino-2-methylthiopyrimidine-5-carboxylate which is reduced by LAH to 4-amino-2-methylthiopyrimidin-5-ylmethanol followed by hydrolysis to 5-hydroxymethyl-cytosine (967) (B-68MI21302, B-68MI21306). 

Sacchettini, J.C., et al. Refined apoprotein stmcture of rat intestinal fatty acid binding protein produced in Escherichia coli. Proc. Natl. Acad. Sci. USA 86 7736-7740, 1989. 

Each subunit of the homotetrameric PFK of Escherichia coli comprises 320 amino acids arranged in two domains, one large and one smaller, both of which have an rx/p structure reminiscent of the Rossman fold (Figure 6.25). 

Polyunsaturated fatty acids pose a slightly more complicated situation for the cell. Consider, for example, the case of linoleic acid shown in Figure 24.24. As with oleic acid, /3-oxidation proceeds through three cycles, and enoyl-CoA isomerase converts the cA-A double bond to a trans-b double bond to permit one more round of /3-oxidation. What results this time, however, is a cA-A enoyl-CoA, which is converted normally by acyl-CoA dehydrogenase to a trans-b, cis-b species. This, however, is a poor substrate for the enoyl-CoA hydratase. This problem is solved by 2,4-dienoyl-CoA reductase, the product of which depends on the organism. The mammalian form of this enzyme produces a trans-b enoyl product, as shown in Figure 24.24, which can be converted by an enoyl-CoA isomerase to the trans-b enoyl-CoA, which can then proceed normally through the /3-oxidation pathway. Escherichia coli possesses a... 

APA + phenylacetic acid Acylation Benzyipenicillin Escherichia coli Alcaiigenes faecalis... 

Another way to enhance the production of an amino acid is to make use of DNA-recombinant technology, often in combination with foe mutations already described. In this way foe negative features of foe micro-organisms are avoided. To help explain this, we will consider a well known fermentation of L-phenylalanine using Escherichia coli. We have already seen foe metabolic pathway leading to foe production of L-phenylalanine in Figure 8.4. 

The cDNA encoding the luciferase of Renilla reniformis has been obtained and expressed in Escherichia coli (Lorenz et al., 1991). The cDNA contained an open reading frame encoding a 314-amino acid sequence. The recombinant Renilla luciferase obtained had a molecular weight of 34,000, and showed an emission maximum at 480 nm in the luminescence reaction of coelenterazine, in good agreement with the data of natural Renilla luciferase. 

One of the commercial methods for production of lysine consists of a two-stage process using two species of bacteria. The carbon sources for production of amino acids are corn, potato starch, molasses, and whey. If starch is used, it must be hydrolysed to glucose to achieve higher yield. Escherichia coli is grown in a medium consisting of glycerol, corn-steep liquor and di-ammonium phosphate under aerobic conditions, with temperature and pH controlled. 

Since 1978, several papers have examined the potential of using immobilised cells in fuel production. Microbial cells are used advantageously for industrial purposes, such as Escherichia coli for the continuous production of L-aspartic acid from ammonium fur-marate.5,6 Enzymes from microorganisms are classified as extracellular and intracellular. If whole microbial cells can be immobilised directly, procedures for extraction and purification can be omitted and the loss of intracellular enzyme activity can be kept to a minimum. Whole cells are used as a solid catalyst when they are immobilised onto a solid support. 

Fowden and Richmond 46) found that azetidine-2-carboxylic acid was growth-inhibitory to Escherichia coli, but no inhibition was observed when both DL-proline and the homolog were present in the... 

Enzyme preparations from liver or microbial sources were reported to show rather high substrate specificity [76] for the natural phosphorylated acceptor d-(18) but, at much reduced reaction rates, offer a rather broad substrate tolerance for polar, short-chain aldehydes [77-79]. Simple aliphatic or aromatic aldehydes are not converted. Therefore, the aldolase from Escherichia coli has been mutated for improved acceptance of nonphosphorylated and enantiomeric substrates toward facilitated enzymatic syntheses ofboth d- and t-sugars [80,81]. High stereoselectivity of the wild-type enzyme has been utilized in the preparation of compounds (23) / (24) and in a two-step enzymatic synthesis of (22), the N-terminal amino acid portion of nikkomycin antibiotics (Figure 10.12) [82]. 

In current practice the fluorescence assay is often followed by the use of hybridization techniques when more selectivity is required. We have for instance used the fluorescence techniques to obtain data on the nucleic acid content of malaria vaccine proteins produced in Escherichia coli. The rapid turnaround time of the fluorescence assay is particularly useful during the early stages of purification to determine the optimal process conditions. After the final process has been arrived at and a variety of methods used to assess the nucleic acid content (including the hybridization techniques), the fluorescence method can be developed for routine quality-control purposes. In certain cases, particularly at high protein concentrations, the dye may bind to the protein with... 

Hirschfield, I.N., Bloch, P.L., Van Bogelen, R.A. Neidhardt, F.C. (1981). Multiple forms of lysyl-transfer ribonucleic acid synthetase in Escherichia coli. Journal of Bacteriology, 146, 345-51. 

Cell permeabilization and uptake of anti-sense peptide-peptide nucleic acid (PNA) into Escherichia coli. J. Biol. Chem. 2002 277 7144-7147. 

Recently, recombinant biocatalysts obtained using Escherichia coli cells were designed for this process. The overexpression of all enzymes required for the process, namely, hydantoinase, carbamoylase, and hydantoin racemase from Arthrobacter sp. DSM 9771 was achieved. These cells were used for production of a-amino acids at the concentration of above 50 g 1 dry cell weight [37]. This is an excellent example presenting the power of biocatalysis with respect to classical catalysis, since a simultaneous use of three different biocatalysts originated from one microorganism can be easily achieved. 

A number of allergens from both honey bee and vespid venoms have been cloned and expressed by either Escherichia coli or baculovirus-infected insect cells (table 1) phospholipase Aj [20], hyaluronidase [21], acid phosphatase [13] and Api m6 [14] from honey bee venom, as well as antigen 5 [22], phospholipase A and hyaluronidase [23] from vespid venom, and dipeptidylpeptidases from both bee and Vespula venoms [15, 16]. Their reactivity with human-specific IgE antibodies to the respective allergens has been documented [11-16, 22, 23] and their specificity is superior... 

Recombinant DNA technology can also be used to design genes that encode for proteins with desired features [34]. The gene can be incorporated into a plasmid, which is then used to transform a bacterial host such as Escherichia coli. Finally, the production of the desired amino acid polymer is performed by the host with a precisely defined sequence and near absolute monodispersity [29, 35]. 

The fact that ) -D-galactosidase from Escherichia coli is inactivated more rapidly in the absence of Mg than in its presence can be taken as evidence that the activation of the triazene 38, that is, formation of )5-D-galactosyl-methyldiazonium ion, proceeds without acid catalysis, because Mg is required for the proton-assisted catalysis of yS-D-galactoside hydrolysis by this enzyme.Additional evidence for the absence of acid catalysis in the de-... 

Wilson NA et al Aspartic acid 26 in reduced Escherichia coli thiore-doxin has a p7 greater than 9. Biochemistry 1995 34 8931. 

C.d. spectroscopy is now being applied to more complicated polysaccharides. The 3-deoxy-D-man o-2-octulopyranosylonic acids found in Escherichia coli LP1092 have been definitely assigned the a-D configuration. The negative nir c.d. band exhibited by this polysaccharide correlates with the negative c.d. of methyl 3-deoxy-a-D-wianno-2-octulopyranosidonic acid rather than the positive c.d. band exhibited by methyl 3-deoxy-)3-D-/ a/ino-2-octulopyranosidonic acid. 

Fig. 1.2 A, peptidoglycan of Escherichia coli. , A -acetylmuramic acid , Af-acetylglucosamine. B, repeating unit of peptidoglycan ofE. coli. L-ala, L-alanine D-glu, D-glutamine DAP, diaminopimelic acid D-aia, D-alanine.

Escherichia coli and Klebsiella pneumoniae subsp, aerogenes produce acid from lactose on this medium, altering the colour of the indicator, and also adsorb some of the indicator which may be precipitated around the growing cells. The organisms causing typhoid and paratyphoid fever and bacillary dysentery do not ferment lactose, and colonies of these organisms appear transparent. 

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