scholarly journals Novel Carotenoid Oxidase Involved in Biosynthesis of 4,4′-Diapolycopene Dialdehyde

2005 ◽  
Vol 71 (6) ◽  
pp. 3294-3301 ◽  
Author(s):  
Luan Tao ◽  
Andreas Schenzle ◽  
J. Martin Odom ◽  
Qiong Cheng
Keyword(s):  
Escherichia Coli ◽  
Aldehyde Dehydrogenase ◽  
Methylotrophic Bacteria ◽  
Purple Pigment ◽  
Methyl Group ◽  
E Coli ◽  
Dehydrogenase Gene ◽  
Carotenoid Synthesis ◽  
Low Activity ◽  
Β Carotene

ABSTRACT Biosynthesis of C30 carotenoids is relatively restricted in nature but has been described in Staphylococcus and in methylotrophic bacteria. We report here identification of a novel gene (crtNb) involved in conversion of 4,4′-diapolycopene to 4,4′-diapolycopene aldehyde. An aldehyde dehydrogenase gene (ald) responsible for the subsequent oxidation of 4,4′-diapolycopene aldehyde to 4,4′-diapolycopene acid was also identified in Methylomonas. CrtNb has significant sequence homology with diapophytoene desaturases (CrtN). However, data from knockout of crtNb and expression of crtNb in Escherichia coli indicated that CrtNb is not a desaturase but rather a novel carotenoid oxidase catalyzing oxidation of the terminal methyl group(s) of 4,4′-diaponeurosporene and 4,4′-diapolycopene to the corresponding terminal aldehyde. It has moderate to low activity on neurosporene and lycopene and no activity on β-carotene or ζ-carotene. Using a combination of C30 carotenoid synthesis genes from Staphylococcus and Methylomonas, 4,4′-diapolycopene dialdehyde was produced in E. coli as the predominant carotenoid. This C30 dialdehyde is a dark-reddish purple pigment that may have potential uses in foods and cosmetics.

Evaluation of Structurally Different Carotenoids inEscherichia coli Transformants as Protectants against UV-B Radiation

1998 ◽  
Vol 64 (5) ◽  
pp. 1972-1974 ◽  
Author(s):  
Gerhard Sandmann ◽  
Silvia Kuhn ◽  
Peter B�ger
Keyword(s):  
Escherichia Coli ◽  
Inescherichia Coli ◽  
Short Term ◽  
E Coli ◽  
Carotenogenic Genes ◽  
Β Carotene

ABSTRACT Escherichia coli cells transformed with several carotenogenic genes to mediate the formation of ζ-carotene, neurosporene, lycopene, β-carotene, and zeaxanthin were exposed to UV-B radiation. Short-term kinetics revealed that endogenous levels of neurosporene and β-carotene protected E. coli against irradiation with UV-B. Zeaxanthin protected against only the photosensitized UV-B treatment. All other carotenoids were ineffective.

scholarly journals Enhancement of S-Adenosylmethionine-Dependent Methylation by Integrating Methanol Metabolism with 5-Methyl-Tetrahydrofolate Formation in Escherichia coli

Catalysts ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1001
Author(s):  
Kenji Okano ◽  
Yu Sato ◽  
Shota Inoue ◽  
Shizuka Kawakami ◽  
Shigeru Kitani ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Methanol Oxidation ◽  
Coli Strain ◽  
Streptomyces Avermitilis ◽  
Regeneration System ◽  
Methanol Metabolism ◽  
Methyl Group ◽  
E Coli ◽  
Whole Cell Biocatalyst ◽  
Methyl Tetrahydrofolate

S-Adenosylmethionine (SAM)-dependent methyltransferases are important tools for the biocatalytic methylation of diverse biomolecules. Methylation by a whole-cell biocatalyst allows the utilization of intrinsic SAM and its regeneration system, which consists of a cyclic and multi-step enzymatic cascade. However, low intracellular availability of 5-methyl-tetrahydrofolate (5-methyl-THF), which functions as a methyl group donor, limits SAM regeneration. Here, we integrated methanol metabolism with 5-methyl-THF formation into SAM-dependent methylation system in Escherichia coli, driven by heterologously expressed methanol dehydrogenase (MDH). The coupling of MDH-catalyzed methanol oxidation with the E. coli endogenous reactions enhances the formation of 5-methyl-THF using methanol as a source of methyl group, thereby promoting both the SAM regeneration and methylation reactions. Co-expression of the mutant MDH2 from Cupriavidus necator N-1 with the O-methyltransferase 5 from Streptomyces avermitilis MA-4680 enhanced O-methylation of esculetin 1.4-fold. Additional overexpression of the E. coli endogenous 5,10-methylene-THF reductase, which catalyzes the last step of 5-methyl-THF formation, further enhanced the methylation reaction by 1.9-fold. Together with deregulation of SAM biosynthesis, the titer of methylated compounds was increased about 20-fold (from 0.023 mM to 0.44 mM). The engineered E. coli strain with enhanced 5-methyl-THF formation is now available as a chassis strain for the production of a variety of methylated compounds.

scholarly journals Properties of Binuclear Rhodium(II) Complexes and Their Antibacterial Activity

1996 ◽  
Vol 3 (4) ◽  
pp. 185-195 ◽  
Author(s):  
Florian P. Pruchnik ◽  
Małgorzata Bień ◽  
Tadeusz Lachowicz
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Nmr Spectroscopy ◽  
Antibacterial Agents ◽  
Structure And Properties ◽  
E Coli ◽  
Nitrogen Ligands ◽  
Low Activity

Binuclear rhodium(II) complexes [Rh2Cl2(μ-OOCR)2(N-N)2], [Rh2(μ-OOCR)2(N-N)2(H2O)2](RCOO)2 and [Rh2Cl2(μ-OOCCH3)(terpy)2](H3O)Cl2.9H2O (R = H, Me, Bun,ph, PhCHOH; N-N = 2,2′-bipyridine (bpy), 1,10-phenanthroline (phen), 2,9-dimethyl-1,10-phenanthroline (dmp) and 6,7-dimethyl-2,3- di(2-pyridyl)quinoxaline (dmpq); terpy 2,2′:6′,2′′-terpyridine) have been synthesized and their structure and properties have been studied by electronic, IR and H1 NMR spectroscopy. Antibacterial activity of these complexes against Staphylococcus aureus and Escherichia coli has been investigated. The most active antibacterial agents against S. aureus were [Rh2(OOCPh)2(phen)2(H2O)2]2+, [Rh2(OOCPh)2(dmpq)2(H2O)2]2+, [Rh2(OOCBu)2(phen)2(H2O)2]2+ and [Rh2-(OOCBu)2(bpy)2(H2O)2]2+ which were considerably more active than the appropriate nitrogen ligands. The complexes show rather low activity against E. coli.

Inhibition Effects on Escherichia coli and Staphylococcus aureus of Purple Pigment Produced by Streptomyces sp. Dagang-2

2014 ◽  
Vol 955-959 ◽  
pp. 390-394
Author(s):  
Hai Jun Liu ◽  
Mi Jia Zhu ◽  
Zhi Min Yuan ◽  
Jun Han ◽  
Jun Yao
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Gram Negative Bacteria ◽  
Purple Pigment ◽  
Acid Base ◽  
High Chemical ◽  
E Coli ◽  
Gram Positive Bacteria ◽  
Inhibition Ability ◽  
High Chemical Stability

A novel actinomycete, Streptomycessp. Dagang-2 was isolated from the oil contaminated soil, which has a high homology of 98.59% with Streptomycesmacrosporeus strain AM2-8. Purple pigment was purified from this strain, which showed a high chemical stability of acid-base, heat and light. Escherichia coli and Staphylococcus aureus were selected to evaluate the inhibition ability of purple pigment combined with microcalorimetric analysis and oxford cup method. The purple pigment showed a striking inhibition effect on Gram-positive bacteria S. aureus, however, it did not emerge an obvious antimicrobial activity against Gram-negative bacteria E. coli. It also could reflect the dynamic process of inhibiting effect to bacteria from purple pigment using microcarlorimetric technique. These results of this study might be useful for gaining more understanding of inhibition mechanisms from purple pigment.

scholarly journals Binuclear Rhodium(II) Complexes With Selective Antibacterial Activity

1997 ◽  
Vol 4 (2) ◽  
pp. 81-88 ◽  
Author(s):  
Małgorzata Bień ◽  
Tadeusz M. Lachowicz ◽  
Agnieszka Rybka ◽  
Florian P. Pruchnik ◽  
Lilianna Trynda
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Antibacterial Activity ◽  
Nmr Spectroscopy ◽  
Antibacterial Agents ◽  
Structure And Properties ◽  
E Coli ◽  
Nitrogen Ligands ◽  
And Staphylococcus Aureus ◽  
Low Activity

Binuclear rhodium(II) complexes [Rh2Cl2(μ-OOCR)2(N-N)2] {R = H, Me; N-N = 2,2'-bipyridine (bpy), 1,10-phenanthroline (phen)} and [Rh2(μ-OOCR)2(N-N)2(H2O)2](RCOO)2 (R = Me, Et;) have been synthesized and their structure and properties have been studied by electronic, IR and H1 NMR spectroscopy. Antibacterial activity of these complexes against Escherichia coli and Staphylococcus aureus has been investigated. The most active antibacterial agents against E. coli were [Rh2Cl2(μ-OOCR)2(N-N)2] and [Rh2(μ-OOCR)2(N-N)2(H2O)2](RCOO)2 {R = H and Me} which were considerably more active than the appropriate nitrogen ligands. The complexes show low activity against S. aureus. The activity of the complexes [Rh2(OOCR)2(N-N)2(H2O)2](OOCR)2 against E. coli decreases in the series: R=H≅CH3>C2H5>C3H7≅C4H9. The reverse order was found in the case of S. aureus.

scholarly journals Convergent In Vivo and In Vitro Selection of Ceftazidime Resistance Mutations at Position 167 of CTX-M-3 β-Lactamase in Hypermutable Escherichia coli Strains

2008 ◽  
Vol 52 (4) ◽  
pp. 1297-1301 ◽  
Author(s):  
Marina N. Stepanova ◽  
Maxim Pimkin ◽  
Anatoly A. Nikulin ◽  
Varvara K. Kozyreva ◽  
Elena D. Agapova ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Molecular Typing ◽  
In Vitro Selection ◽  
Resistance Mutations ◽  
Natural Evolution ◽  
E Coli ◽  
Low Activity ◽  
Selection Of

ABSTRACT We report on a novel CTX-M extended-spectrum β-lactamase (ESBL), designated CTX-M-42, with enhanced activity toward ceftazidime. CTX-M-42 was identified in a hypermutable Escherichia coli nosocomial isolate (isolate Irk2320) and is a Pro167Thr amino acid substitution variant of CTX-M-3. By molecular typing of ESBL-producing E. coli strains previously isolated in the same hospital ward, we were able to identify a putative progenitor (strain Irk1224) of Irk2320, which had a mutator phenotype and harbored the CTX-M-3 β-lactamase. To reproduce the natural evolution of CTX-M-3, we selected for ceftazidime resistance mutations in bla CTX-M-3 gene in vitro both in clinical isolate Irk1224 and in laboratory-derived hypermutable (mutD5) strain GM2995. These experiments yielded CTX-M-3Pro167Ser and CTX-M-3Asn136Lys mutants which conferred higher levels of resistance to ceftazidime than to cefotaxime. CTX-M-3Asn136Lys had a level of low activity toward ampicillin, which may explain its absence from clinical isolates. We conclude that the selection of CTX-M-42 could have occurred in vivo following treatment with ceftazidime and was likely facilitated by the hypermutable background.

scholarly journals Expression of an exogenous isopentenyl diphosphate isomerase gene enhances isoprenoid biosynthesis in Escherichia coli

1997 ◽  
Vol 324 (2) ◽  
pp. 421-426 ◽  
Author(s):  
Susumu KAJIWARA ◽  
Paul D. FRASER ◽  
Keiji KONDO ◽  
Norihiko MISAWA
Keyword(s):  
Escherichia Coli ◽  
Nucleotide Sequence ◽  
Genomic Library ◽  
Haematococcus Pluvialis ◽  
Isoprenoid Biosynthesis ◽  
Nucleotide Sequence Analysis ◽  
Efficient Production ◽  
Isopentenyl Diphosphate ◽  
E Coli ◽  
Β Carotene

Escherichia coli expressing the Erwinia carotenoid biosynthesis genes, crtE, crtB, crtI and crtY, form yellow-coloured colonies due to the presence of β-carotene. This host was used as a visible marker for evaluating regulatory systems operating in isoprenoid biosynthesis of E. coli. cDNAs enhancing carotenoid levels were isolated from the yeast Phaffia rhodozyma and the green alga Haematococcus pluvialis. Nucleotide sequence analysis indicated that they coded for proteins similar to isopentenyl diphosphate (IPP) isomerase of the yeast Saccharomyces cerevisiae. Determination of enzymic activity confirmed the identity of the gene products as IPP isomerases. The corresponding gene was isolated from the genomic library of S. cerevisiae based on its nucleotide sequence, and was confirmed to have the same effect as the above two IPP isomerase genes when introduced into the E. coli transformant accumulating β-carotene. In the three E. coli strains carrying the individual exogenous IPP isomerase genes, the increases in carotenoid levels are comparable to the increases in IPP isomerase enzyme activity with reference to control strains possessing the endogenous gene alone. These results imply that IPP isomerase forms an influential step in isoprenoid biosynthesis of the prokaryote E. coli, with potential for the efficient production of industrially useful isoprenoids by metabolic engineering.

Homofermentative Production of d- orl-Lactate in Metabolically Engineered Escherichia coli RR1

1999 ◽  
Vol 65 (4) ◽  
pp. 1384-1389 ◽  
Author(s):  
Dong-Eun Chang ◽  
Heung-Chae Jung ◽  
Joon-Shick Rhee ◽  
Jae-Gu Pan
Keyword(s):  
Escherichia Coli ◽  
Lactate Dehydrogenase ◽  
Lactobacillus Casei ◽  
Lactate Production ◽  
Anaerobic Conditions ◽  
E Coli ◽  
Fermentation Product ◽  
Dehydrogenase Gene ◽  
Mutant Strains ◽  
Optically Pure

ABSTRACT We investigated metabolic engineering of fermentation pathways inEscherichia coli for production of optically pured- or l-lactate. Several pta mutant strains were examined, and a pta mutant of E. coli RR1 which was deficient in the phosphotransacetylase of the Pta-AckA pathway was found to metabolize glucose tod-lactate and to produce a small amount of succinate by-product under anaerobic conditions. An additional mutation inppc made the mutant produce d-lactate like a homofermentative lactic acid bacterium. When the pta ppcdouble mutant was grown to higher biomass concentrations under aerobic conditions before it shifted to the anaerobic phase ofd-lactate production, more than 62.2 g ofd-lactate per liter was produced in 60 h, and the volumetric productivity was 1.04 g/liter/h. To examine whether the blocked acetate flux could be reoriented to a nonindigenousl-lactate pathway, an l-lactate dehydrogenase gene from Lactobacillus casei was introduced into apta ldhA strain which lacked phosphotransacetylase andd-lactate dehydrogenase. This recombinant strain was able to metabolize glucose to l-lactate as the major fermentation product, and up to 45 g of l-lactate per liter was produced in 67 h. These results demonstrate that the central fermentation metabolism of E. coli can be reoriented to the production of d-lactate, an indigenous fermentation product, or to the production of l-lactate, a nonindigenous fermentation product.

scholarly journals The yiaE Gene, Located at 80.1 Minutes on the Escherichia coli Chromosome, Encodes a 2-Ketoaldonate Reductase

1998 ◽  
Vol 180 (22) ◽  
pp. 5984-5988 ◽  
Author(s):  
Do-Young Yum ◽  
Bong-Yong Lee ◽  
Dae-Hyum Hahm ◽  
Jae-Gu Pan
Keyword(s):  
Escherichia Coli ◽  
Amino Acid ◽  
Amino Acid Sequence ◽  
Metal Chelate ◽  
Reading Frame ◽  
Sequencing Project ◽  
E Coli ◽  
Dehydrogenase Gene ◽  
Translational Start

ABSTRACT An open reading frame located in the bisC-cspAintergenic region, or at 80.1 min on the Escherichia colichromosome, encodes a hypothetical 2-hydroxyacid dehydrogenase, which was identified as a result of the E. coli Genome Sequencing Project. We report here that the product of the gene (yiaE) is a 2-ketoaldonate reductase (2KR). The gene was cloned and expressed with a C-terminal His tag in E. coli, and the protein was purified by metal-chelate affinity chromatography. The determination of the NH2-terminal amino acid sequence of the protein defined the translational start site of this gene. The enzyme was found to be a 2KR catalyzing the reduction of 2,5-diketo-d-gluconate to 5-keto-d-gluconate, 2-keto-d-gluconate (2KDG) to d-gluconate, 2-keto-l-gulonate tol-idonate. The reductase was optimally active at pH 7.5, with NADPH as a preferred electron donor. The deduced amino acid sequence showed 69.4% identity with that of 2KR from Erwinia herbicola. Disruption of this gene on the chromosome resulted in the loss of 2KR activity in E. coli. E. coli W3110 was found to grow on 2KDG, whereas the mutant deficient in 2KR activity was unable to grow on 2KDG as the carbon source, suggesting that 2KR is responsible for the catabolism of 2KDG in E. coli and the diminishment of produced 2KDG from d-gluconate in the cultivation of E. coli harboring a cloned gluconate dehydrogenase gene.

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