Construction of a Novel Recombinant Escherichia coli Strain Capable of Producing 1,3–propanediol

2011 ◽  
Vol 396-398 ◽  
pp. 2499-2502 ◽  
Author(s):  
Xiang Hui Qi ◽  
Qi Guo ◽  
Yu Tuo Wei ◽  
Hong Xu ◽  
Ri Bo Huang
Keyword(s):  
Escherichia Coli ◽  
Specific Activity ◽  
Gel Filtration ◽  
Coli Strain ◽  
Optimal Temperature ◽  
Recombinant Enzymes ◽  
Microbial Conversion ◽  
Gene Encoding ◽  
E Coli ◽  
Nickel Chelate

1, 3-propanediol (1, 3-PD) is biologically synthesized by glycerol dehydratase (GDHt) and 1, 3-propanediol dehydrogenase (PDOR). In present study, the gldABC gene, encoding GDHt from Klebsiella pneumoniae and the yqhD gene, encoding PDOR isoenzyme from E.coli BL21 were cloned and co-expressed in E.coli JM109 using plasmid pSE380. The over-expressed recombinant enzymes were purified by nickel-chelate chromatography combined with gel filtration to study the properties. Optimal temperature and pH of recombinant GDHt with specific activity of 85.8 U/mg were 45 °C and 9.0; and optimal temperature and pH of recombinant YqhD with specific activity of 80.0 U/mg were 37 °C, 7.0. The microbial conversion of 1,3-PD from glycerol by this recombinant E. coli strain was studied and the production of 1,3-PD was about 28.0 g/l.

Overexpression and Characterization of the Gene Encoding 1,3-Propanediol Oxidoreductase of Citrobacter freundii

2014 ◽  
Vol 636 ◽  
pp. 121-124
Author(s):  
Xiang Hui Qi ◽  
Jing Fei Zhu ◽  
Yan Luo ◽  
Jing Lin ◽  
Xu Wang ◽  
...  
Keyword(s):  
Specific Activity ◽  
Gel Filtration ◽  
Raw Material ◽  
Biological Synthesis ◽  
Citrobacter Freundii ◽  
Gene Encoding ◽  
E Coli ◽  
Nickel Chelate ◽  
Future Work

Glycerol can be biologically converted to 1,3-propanediol (1,3-PD), a key raw material required for the synthesis of polytrimethylene terephthalate and other polyester fibers. 1,3-propanediol oxidoreductase (PDOR) is the rate-limiting enzyme in 1,3-PD synthesis biologically pathway. In present study, the dhaT gene encoding PDOR was cloned from Citrobacter freundii and overexpressed in E. coli BL21. The recombinant enzyme was purified by nickel-chelate chromatography combined with gel filtration to study the enzymatic characterization. Specific activity of recombinant PDOR was 55.2 U/mg. Km and Vmax values were 8.9 mM, 40.2 U/mg respectively. Holoenzyme of PDOR maybe a decamer of which a monomer has a molecular mass of 43 kDa. This research may form a basis for the future work on biological synthesis of 1, 3-PD.

scholarly journals Prevalence of a Gene Encoding Adhesin Involved in Diffuse Adherence among Escherichia Coli Isolates in Pigs with Postweaning Diarrhea or Edema Disease

2003 ◽  
Vol 15 (4) ◽  
pp. 378-381 ◽  
Author(s):  
Seung-Kwon Ha ◽  
Changsun Choi ◽  
Chanhee Chae
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Coli Strain ◽  
Isolation Rate ◽  
Gene Encoding ◽  
Edema Disease ◽  
E Coli ◽  
Heat Stable ◽  
Fimbrial Adhesins ◽  
Postweaning Diarrhea

A total of 604 Escherichia coli strains isolated from weaned pigs with diarrhea or edema disease on 653 swine farms were screened for the presence of the adhesin involved in diffuse adherence (AIDA) gene by polymerase chain reaction (PCR). Escherichia coli isolates that carried AIDA genes were also tested by PCR for the detection of 5 fimbriae (F4, F5, F6, F18, and F41), 3 heat-stable (STa, STb, and EAST1) and 1 heat-labile (LT) enterotoxin, and Shiga toxin 2e (Stx2e) genes. Forty-five (7.5%) of the 604 E. coli isolates carried the gene for AIDA. Of these 45 isolates, 5 (11.1%) carried EAST1 genes only, 1 (2.2%) carried genes for at least one of the fimbrial adhesins, 12 (26.7%) carried genes for at least one of the toxins, and 27 (60%) carried genes for at least one of the fimbrial adhesins and toxins. Fifty-one percent of strains that carried AIDA genes carried Stx2e genes, and 40% of strains that carried AIDA genes carried F18ab. The isolation rate of enterotoxigenic E. coli strain carrying genes for AIDA was 87%, and the isolation rate of Shiga toxin-producing E. coli strain carrying genes for AIDA was 49%. AIDA may represent an important virulence determinant in pigs with postweaning diarrhea or edema disease.

scholarly journals Expression of a Temperature-Sensitive Esterase in a Novel Chaperone-Based Escherichia coli Strain

2004 ◽  
Vol 70 (8) ◽  
pp. 4499-4504 ◽  
Author(s):  
Manuel Ferrer ◽  
Tatyana N. Chernikova ◽  
Kenneth N. Timmis ◽  
Peter N. Golyshin
Keyword(s):  
Escherichia Coli ◽  
Recombinant Proteins ◽  
Growth Temperature ◽  
Specific Activity ◽  
Maximum Growth ◽  
Maximum Growth Rate ◽  
Coli Strain ◽  
Temperature Sensitive ◽  
Psychrophilic Bacterium ◽  
E Coli

ABSTRACT A new principle for expression of heat-sensitive recombinant proteins in Escherichia coli at temperatures close to 4°C was experimentally evaluated. This principle was based on simultaneous expression of the target protein with chaperones (Cpn60 and Cpn10) from a psychrophilic bacterium, Oleispira antarctica RB8T, that allow E. coli to grow at high rates at 4°C (maximum growth rate, 0.28 h−1) (M. Ferrer, T. N. Chernikova, M. Yakimov, P. N. Golyshin, and K. N. Timmis, Nat. Biotechnol. 21:1266-1267, 2003). The expression of a temperature-sensitive esterase in this host at 4 to 10°C yielded enzyme specific activity that was 180-fold higher than the activity purified from the non-chaperonin-producing E. coli strain grown at 37°C (32,380 versus 190 μmol min−1 g−1). We present evidence that the increased specific activity was not due to the low growth temperature per se but was due to the fact that low temperature was beneficial to folding, with or without chaperones. This is the first report of successful use of a chaperone-based E. coli strain to express heat-labile recombinant proteins at temperatures below the theoretical minimum growth temperature of a common E. coli strain (7.5°C).

scholarly journals Asymptomatic bacteriuria Escherichia coli strain 83972 carries mutations in the foc locus and is unable to express F1C fimbriae

Microbiology ◽  
2006 ◽  
Vol 152 (6) ◽  
pp. 1799-1806 ◽  
Author(s):  
Viktoria Roos ◽  
Mark A. Schembri ◽  
Glen C. Ulett ◽  
Per Klemm
Keyword(s):  
Escherichia Coli ◽  
Urinary Tract ◽  
Gene Cluster ◽  
Asymptomatic Bacteriuria ◽  
Human Kidney ◽  
Coli Strain ◽  
Gene Encoding ◽  
Symptomatic Urinary Tract Infection ◽  
E Coli ◽  
Colonization Factor

Escherichia coli is the most common organism associated with asymptomatic bacteriuria (ABU). In contrast to uropathogenic E. coli (UPEC), which causes symptomatic urinary tract infection (UTI), very little is known about the mechanisms by which these strains colonize the urinary tract. Bacterial adhesion conferred by specific surface-associated adhesins is normally considered as a prerequisite for colonization of the urinary tract. The prototype ABU E. coli strain 83972 was originally isolated from a girl who had carried it asymptomatically for 3 years. This study characterized the molecular status of one of the primary adhesion factors known to be associated with UTI, namely F1C fimbriae, encoded by the foc gene cluster. F1C fimbriae recognize receptors present in the human kidney and bladder. Expression of the foc genes was found to be up-regulated in human urine. It was also shown that although strain 83972 contains a seemingly intact foc gene cluster, F1C fimbriae are not expressed. Sequencing and genetic complementation revealed that the focD gene, encoding a component of the F1C transport and assembly system, was non-functional, explaining the inability of strain 83972 to express this adhesin. The data imply that E. coli 83972 has lost its ability to express this important colonization factor as a result of host-driven evolution. The ancestor of the strain seems to have been a pyelonephritis strain of phylogenetic group B2. Strain 83972 therefore represents an example of bacterial adaptation from pathogenicity to commensalism through virulence factor loss.

scholarly journals Fermentative Production of Thymidine by a Metabolically Engineered Escherichia coli Strain

2009 ◽  
Vol 75 (8) ◽  
pp. 2423-2432 ◽  
Author(s):  
Hyeon Cheol Lee ◽  
Jin Ha Kim ◽  
Jin Sook Kim ◽  
Wonhee Jang ◽  
Sang Yong Kim
Keyword(s):  
Escherichia Coli ◽  
De Novo ◽  
Excision Repair ◽  
Coli Strain ◽  
High Yield ◽  
Gene Encoding ◽  
E Coli ◽  
Fermentative Production ◽  
Batch Fermenter ◽  
Degradation Activity

ABSTRACT Thymidine is an important precursor in the production of various antiviral drugs, including azidothymidine for the treatment of AIDS. Since thymidine-containing nucleotides are synthesized only by the de novo pathway during DNA synthesis, it is not easy to produce a large amount of thymidine biologically. In order to develop a host strain to produce thymidine, thymidine phosphorylase, thymidine kinase, and uridine phosphorylase genes were deleted from an Escherichia coli BL21 strain to develop BLdtu. Since the genes coding for the enzymes related to the nucleotide salvage pathway were disrupted, BLdtu was unable to utilize thymidine or thymine, and thymidine degradation activity was completely abrogated. We additionally expressed T4 thymidylate synthase, T4 nucleotide diphosphate reductase, bacteriophage PBS2 TMP phosphohydrolase, E. coli dCTP deaminase, and E. coli uridine kinase in the BLdtu strain to develop a thymidine-producing strain (BLdtu24). BLdtu24 produced 649.3 mg liter−1 of thymidine in a 7-liter batch fermenter for 24 h, and neither thymine nor uridine was detected. However, the dUTP/dTTP ratio was increased in BLdtu24, which could lead to increased double-strand breakages and eventually to cell deaths during fermentation. To enhance thymidine production and to prevent cell deaths during fermentation, we disrupted a gene (encoding uracil-DNA N-glycosylase) involved in DNA excision repair to suppress the consumption of dTTP and developed BLdtug24. Compared with the thymidine production in BLdtu24, the thymidine production in BLdtug24 was increased by ∼1.2-fold (740.3 mg liter−1). Here, we show that a thymidine-producing strain with a relatively high yield can be developed using a metabolic engineering approach.

scholarly journals RegR Virulence Regulon of Rabbit-Specific Enteropathogenic Escherichia coli Strain E22

2013 ◽  
Vol 81 (4) ◽  
pp. 1078-1089 ◽  
Author(s):  
Yogitha N. Srikhanta ◽  
Dianna M. Hocking ◽  
Judyta Praszkier ◽  
Matthew J. Wakefield ◽  
Roy M. Robins-Browne ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Regulatory Protein ◽  
Bioinformatic Analysis ◽  
Coli Strain ◽  
Mobility Shift ◽  
Gene Encoding ◽  
Gene Target ◽  
Content Type ◽  
E Coli ◽  
Genes Encoding

ABSTRACTAraC-like regulators play a key role in the expression of virulence factors in enteric pathogens, such as enteropathogenicEscherichia coli(EPEC), enterotoxigenicE. coli, enteroaggregativeE. coli, andCitrobacter rodentium. Bioinformatic analysis of the genome of rabbit-specific EPEC (REPEC) strain E22 (O103:H2) revealed the presence of a gene encoding an AraC-like regulatory protein, RegR, which shares 71% identity to the global virulence regulator, RegA, ofC. rodentium. Microarray analysis demonstrated that RegR exerts 25- to 400-fold activation on transcription of several genes encoding putative virulence-associated factors, including a fimbrial operon (SEF14), a serine protease, and an autotransporter adhesin. These observations were confirmed by proteomic analysis of secreted and heat-extracted surface-associated proteins. The mechanism of RegR-mediated activation was investigated by using its most highly upregulated gene target,sefA. Transcriptional analyses and electrophoretic mobility shift assays showed that RegR activates the expression ofsefAby binding to a region upstream of thesefApromoter, thereby relieving gene silencing by the global regulatory protein H-NS. Moreover, RegR was found to contribute significantly to virulence in a rabbit infection experiment. Taken together, our findings indicate that RegR controls the expression of a series of accessory adhesins that significantly enhance the virulence of REPEC strain E22.

Cloning and expression of the beta-D-phosphogalactoside galactohydrolase gene of Lactobacillus casei in Escherichia coli K-12

1982 ◽  
Vol 152 (3) ◽  
pp. 1138-1146
Author(s):  
L J Lee ◽  
J B Hansen ◽  
E K Jagusztyn-Krynicka ◽  
B M Chassy
Keyword(s):  
Escherichia Coli ◽  
Lactobacillus Casei ◽  
Specific Activity ◽  
Protein Product ◽  
Coli Strain ◽  
Cloning And Expression ◽  
E Coli ◽  
Lactose Metabolism ◽  
Gene Coding ◽  
K 12

Lactose metabolism in Lactobacillus casei 64H is associated with the presence of plasmid pLZ64. This plasmid determines both phosphoenolpyruvate-dependent phosphotransferase uptake of lactose and beta-D-phosphogalactoside galactohydrolase. A shotgun clone bank of chimeric plasmids containing restriction enzyme digest fragments of pLZ64 DNA was constructed in Escherichia coli K-12. One clone contained the gene coding for beta-D-phosphogalactoside galactohydrolase on a 7.9-kilobase PstI fragment cloned into the vector pBR322 in E. coli strain chi 1849. The beta-D-phosphogalactoside galactohydrolase enzyme isolated from E. coli showed no difference from that isolated from L. casei, and specific activity of beta-D-phosphogalactoside galactohydrolase was stimulated 1.8-fold in E. coli by growth in media containing beta-galactosides. A restriction map of the recombinant plasmid was compiled, and with that information, a series of subclones was constructed. From an analysis of the proteins produced by minicells prepared from transformant E. coli cells containing each of the recombinant subclone plasmids, it was found that the gene for the 56-kilodalton beta-D-phosphogalactoside galactohydrolase was transcribed from an L. casei-derived promoter. The gene for a second protein product (43 kilodaltons) was transcribed in the opposite direction, presumably under the control of a promoter in pBR322. The relationship of this second product to the lactose metabolism genes of L. casei is at present unknown.

scholarly journals Construction of Deoxyriboaldolase-Overexpressing Escherichia coli and Its Application to 2-Deoxyribose 5-Phosphate Synthesis from Glucose and Acetaldehyde for 2′-Deoxyribonucleoside Production

2003 ◽  
Vol 69 (7) ◽  
pp. 3791-3797 ◽  
Author(s):  
Nobuyuki Horinouchi ◽  
Jun Ogawa ◽  
Takafumi Sakai ◽  
Takako Kawano ◽  
Seiichiro Matsumoto ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Amino Acid ◽  
Specific Activity ◽  
Cell Extract ◽  
Predicted Amino Acid Sequence ◽  
Enzymatic Reactions ◽  
Chromosomal Dna ◽  
Gene Encoding ◽  
Reading Frame ◽  
E Coli

ABSTRACT The gene encoding a deoxyriboaldolase (DERA) was cloned from the chromosomal DNA of Klebsiella pneumoniae B-4-4. This gene contains an open reading frame consisting of 780 nucleotides encoding 259 amino acid residues. The predicted amino acid sequence exhibited 94.6% homology with the sequence of DERA from Escherichia coli. The DERA of K. pneumoniae was expressed in recombinant E. coli cells, and the specific activity of the enzyme in the cell extract was as high as 2.5 U/mg, which was threefold higher than the specific activity in the K. pneumoniae cell extract. One of the E. coli transformants, 10B5/pTS8, which had a defect in alkaline phosphatase activity, was a good catalyst for 2-deoxyribose 5-phosphate (DR5P) synthesis from glyceraldehyde 3-phosphate and acetaldehyde. The E. coli cells produced DR5P from glucose and acetaldehyde in the presence of ATP. Under the optimal conditions, 100 mM DR5P was produced from 900 mM glucose, 200 mM acetaldehyde, and 100 mM ATP by the E. coli cells. The DR5P produced was further transformed to 2′-deoxyribonucleoside through coupling the enzymatic reactions of phosphopentomutase and nucleoside phosphorylase. These results indicated that production of 2′-deoxyribonucleoside from glucose, acetaldehyde, and a nucleobase is possible with the addition of a suitable energy source, such as ATP.

Isolation of an Escherichia coli strain mutant unable to form biofilm on polystyrene and to adhere to human pneumocyte cells: involvement of tryptophanase

2002 ◽  
Vol 48 (2) ◽  
pp. 132-137 ◽  
Author(s):  
P Di Martino ◽  
A Merieau ◽  
R Phillips ◽  
N Orange ◽  
C Hulen
Keyword(s):  
Escherichia Coli ◽  
Biofilm Formation ◽  
A549 Cells ◽  
Coli Strain ◽  
Gene Encoding ◽  
Cell Monolayers ◽  
E Coli ◽  
Transposon Insertion ◽  
Abiotic Surfaces ◽  
Tryptophanase Activity

Escherichia coli adherence to biotic and abiotic surfaces constitutes the first step of infection by promoting colonization and biofilm formation. The aim of this study was to gain a better understanding of the relationship between E. coli adherence to different biotic surfaces and biofilm formation on abiotic surfaces. We isolated mutants defective in A549 pneumocyte cells adherence, fibronectin adherence, and biofilm formation by random transposition mutagenesis and sequential passages over A549 cell monolayers. Among the 97 mutants tested, 80 were decreased in biofilm formation, 8 were decreased in A549 cells adherence, 7 were decreased in their adherence to fibronectin, and 17 had no perturbations in either of the three phenotypes. We observed a correlation between adherence to fibronectin or A549 cells and biofilm formation, indicating that biotic adhesive factors are involved in biofilm formation by E. coli. Molecular analysis of the mutants revealed that a transposon insertion in the tnaA gene encoding for tryptophanase was associated with a decrease in both A549 cells adherence and biofilm formation by E. coli. The complementation of the tnaA mutant with plasmid-located wild-type tnaA restored the tryptophanase activity, epithelial cells adherence, and biofilm formation on polystyrene. The possible mechanism of tryptophanase involvement in E. coli adherence and biofilm formation is discussed.Key words: Escherichia coli, biofilm, adherence, A549 cells, fibronectin, tryptophanase.

Gene cloning, protein purification, and enzymatic properties of multicopper oxidase, fromKlebsiellasp. 601

2008 ◽  
Vol 54 (9) ◽  
pp. 725-733 ◽  
Author(s):  
Yang Li ◽  
Jiao Yin ◽  
Guosheng Qu ◽  
Luchao Lv ◽  
Yadong Li ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Amino Acids ◽  
Amino Acid ◽  
Kinetic Studies ◽  
Multicopper Oxidase ◽  
Coli Strain ◽  
Gene Encoding ◽  
E Coli ◽  
C Terminus ◽  
Optimal Ph

A gene encoding a putative multicopper oxidase (MCO) was cloned from the soil bacterium Klebsiella sp. 601 and its corresponding enzyme was overexpressed in an Escherichia coli strain. Klebsiella sp. 601 MCO is composed of 536 amino acids with a molecular mass of 58.2 kDa. Theoretical calculation gave a pI value of 6.11. The amino acid sequence of Klebsiella sp. 601 MCO is strongly homologous to that of E. coli CueO with a similarity of 90% and an identity of 78%. Unlike E. coli CueO, Klebsiella sp. 601 MCO contains an extra 20 amino acids close to its C-terminus. The enzyme was purified to homogeneity by Ni-affinity chromatography. The purified enzyme was capable of using DMP (2,6-dimethoxyphenol), ABTS (2,2′-azino-bis(3-ethylbenzthiazolinesulfonic acid)), and SGZ (syringaldazine) as substrates with an optimal pH of 8.0 for DMP, 3.0 for ABTS, and 7.0 for SGZ. Klebsiella sp. 601 MCO was quite stable at pH 7.0 in which its activity was constant for 25 h without any significant change. Kinetic studies gave Km, kcat, and kcat/Kmvalues of 0.49 mmol·L–1, 1.08 × 103s–1, and 2.23 × 103s–1·mmol–1·L, respectively, for DMP, 5.63 mmol·L–1, 6.64 × 103s–1, and 1.18 × 103s–1·mmol–1·L for ABTS, and 0.023 mmol·L–1, 11 s–1, and 4.68 × 102s–1·mmol–1·L for SGZ.

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