scholarly journals Production of Resveratrol in Recombinant Microorganisms

2006 ◽  
Vol 72 (8) ◽  
pp. 5670-5672 ◽  
Author(s):  
Jules Beekwilder ◽  
Rianne Wolswinkel ◽  
Harry Jonker ◽  
Robert Hall ◽  
C. H. Ric de Vos ◽  
...  

ABSTRACT Resveratrol production in Saccharomyces cerevisiae was compared to that in Escherichia coli. In both systems, 4-coumarate:coenzyme A ligase from tobacco and stilbene synthase from grapes were expressed. When p-coumaric acid was used as the precursor, resveratrol accumulations in the culture medium were observed to be comparable in E. coli (16 mg/liter) and yeast (6 mg/liter).

Biosensors ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 40
Author(s):  
Mohd Kamuri ◽  
Zurina Zainal Abidin ◽  
Mohd Yaacob ◽  
Mohd Hamidon ◽  
Nurul Md Yunus ◽  
...  

This paper describes the development of an integrated system using a dry film resistant (DFR) microfluidic channel consisting of pulsed field dielectrophoretic field-flow-fractionation (DEP-FFF) separation and optical detection. The prototype chip employs the pulse DEP-FFF concept to separate the cells (Escherichia coli and Saccharomyces cerevisiae) from a continuous flow, and the rate of release of the cells was measured. The separation experiments were conducted by changing the pulsing time over a pulsing time range of 2–24 s and a flow rate range of 1.2–9.6 μ L min − 1 . The frequency and voltage were set to a constant value of 1 M Hz and 14 V pk-pk, respectively. After cell sorting, the particles pass the optical fibre, and the incident light is scattered (or absorbed), thus, reducing the intensity of the transmitted light. The change in light level is measured by a spectrophotometer and recorded as an absorbance spectrum. The results revealed that, generally, the flow rate and pulsing time influenced the separation of E. coli and S. cerevisiae. It was found that E. coli had the highest rate of release, followed by S. cerevisiae. In this investigation, the developed integrated chip-in-a lab has enabled two microorganisms of different cell dielectric properties and particle size to be separated and subsequently detected using unique optical properties. Optimum separation between these two microorganisms could be obtained using a longer pulsing time of 12 s and a faster flow rate of 9.6 μ L min − 1 at a constant frequency, voltage, and a low conductivity.


Diseases ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 11 ◽  
Author(s):  
Shane Whelan ◽  
Mary Claire O’Grady ◽  
Dan Corcoran ◽  
Karen Finn ◽  
Brigid Lucey

Antibiotic resistance is increasing to an extent where efficacy is not guaranteed when treating infection. Biofilm formation has been shown to complicate treatment, whereby the formation of biofilm is associated with higher minimum inhibitory concentration values of antibiotic. The objective of the current paper was to determine whether biofilm formation is variable among uropathogenic Escherichia coli isolates and whether formation is associated with recurrent urinary tract infection (UTI), and whether it can be predicted by phenotypic appearance on culture medium A total of 62 E. coli isolates that were reported as the causative agent of UTI were studied (33 from patients denoted as having recurrent UTI and 29 from patients not specified as having recurrent UTI). The biofilm forming capability was determined using a standard microtitre plate method, using E. coli ATCC 25922 as the positive control. The majority of isolates (93.6%) were found to be biofilm formers, whereby 81% were denoted as strong or very strong producers of biofilm when compared to the positive control. Through the use of a Wilcox test, the difference in biofilm forming propensity between the two patient populations was found to not be statistically significant (p = 0.5). Furthermore, it was noted that colony morphology was not a reliable predictor of biofilm-forming propensity. The findings of this study indicate that biofilm formation is very common among uropathogens, and they suggest that the biofilm-forming capability might be considered when treating UTI. Clinical details indicating a recurrent infection were not predictors of biofilm formation.


1961 ◽  
Vol 39 (10) ◽  
pp. 1551-1558 ◽  
Author(s):  
A. J. Finlayson ◽  
F. J. Simpson

When 2,6-diaminopimelicacid-1,7-C14was added to growing cultures of Bacillus megaterium, Staphlococcus aureus, and Escherichia coli, 8–9% of added carbon-14 appeared in the cellular lysine. Similar experiments with Proteus vulgaris, Streptomyces griseus, Aspergillus flavus, and Lactobacillus arabinosus resulted in less than 0.3% of the added carbon-14 being incorporated into the cellular lysine. Leuconostoc mesenteroides converted 0.6% of the added DAP-1,7-C14to lysine-1-C14.Over 90% of the carbon-14 in cell lysine from B. megaterium and L. mesenteroides was found in the carboxyl carbon. This was interpreted as indicating a direct decarboxylation of DAP-1,7-C14to lysine-1-C14. About 70% of the carbon-14 in the lysine from cells of S. aureus and E. coli was found in the carboxyl carbon, thus suggesting that some lysine comes from sources other than 2,6-diaminopimelic acid.Those organisms that actively decarboxylated DAP-1,7-C14to form lysine-C14also synthesized DAP and excreted it into the culture medium during growth.


1997 ◽  
Vol 327 (3) ◽  
pp. 847-851 ◽  
Author(s):  
Zengji LI ◽  
Yue SUN ◽  
L. David THURLOW

Twenty-one RNA minihelices, resembling the coaxially stacked acceptor- /T-stems and T-loop found along the top of a tRNA's three-dimensional structure, were synthesized and used as substrates for ATP/CTP:tRNA nucleotidyltransferases from Escherichia coli and Saccharomyces cerevisiae. The sequence of nucleotides in the loop varied at positions corresponding to residues 56, 57 and 58 in the T-loop of a tRNA. All minihelices were substrates for both enzymes, and the identity of bases in the loop affected the interaction. In general, RNAs with purines in the loop were better substrates than those with pyrimidines, although no single base identity absolutely determined the effectiveness of the RNA as substrate. RNAs lacking bases near the 5ʹ-end were good substrates for the E. coli enzyme, but were poor substrates for that from yeast. The apparent Km values for selected minihelices were 2-3 times that for natural tRNA, and values for apparent Vmax were lowered 5-10-fold.


1996 ◽  
Vol 117 (1) ◽  
pp. 11-16 ◽  
Author(s):  
M. Čobeljić ◽  
B. Miljković-Selimović ◽  
D. Paunović-Todosijević ◽  
Z. Veličković ◽  
Z. Lepšanović ◽  
...  

SummaryOver a 9-day period in February 1995, 16 newborn babies (age range 2–11 days) and 3 infants (24, 47 and 180 days of age) in a neonatal nursery ward developed diarrhoea accompanied by pyrexia and weight loss. Known enteropathogens were not detected in their stools butEscherichia colidisplaying aggregative adherence to HEp-2 cells (enteroaggregativeE. coli) were found in 12 (63%) ill infants and in none of 5 well neonates (P= 0·02). The illness lasted 3–9 days (mean 5·2) in 16 babies, whereas in 3 neonates it showed a protracted course of 18–20 days. The source of infection and the mode of transmission remained unclear. The outbreak isolates manifested properties common in this new group of diarrhoeagenicE. coli: mannose-resistant haemagglutination, haemolysis on blood agar, and clump formation in liquid culture medium. They belonged to the O4E. coliserogroup and expressed multiple antibiotic resistance.


2011 ◽  
Vol 32 (2) ◽  
pp. 73
Author(s):  
John A Fuerst

Microbial diversity explores the universe of microorganisms beyond classical models such as Escherichia coli, influenza virus, or Saccharomyces cerevisiae. Exploring such new microbial worlds is essential for a microbiology which needs to learn about all the scientific and practical possibilities offered by billions of years of microbial evolution. Here we illustrate some examples of how studying a wide range of microbial diversity can assist microbiology as a fundamental and a practical science.


2019 ◽  
Vol 88 (2) ◽  
pp. 233-241
Author(s):  
Yujie Chen ◽  
Chen Aorigele ◽  
Chunjie Wang ◽  
Wenqian Hou ◽  
Yunsheng Zheng ◽  
...  

The yeast Saccharomyces cerevisiae from koumiss has been shown to have antibacterial effects on Escherichia coli, possibly by producing antibacterial compound in metabolism; however, there is limited knowledge about its application in animal production. We therefore investigated the effects of an antibacterial compound of S. cerevisiae from koumiss on the immune function and caecal microflora of mice challenged with pathogenic Escherichia coli O8. Three groups were formed: negative control (NC), positive control (PC), and the antibacterial compound of S. cerevisiae at pH 2.0 (S2). Mice in the NC and PC groups were orally administered phosphate buffer solution (PBS) for 7 d. At 4 d, E. coli O8 was administered intraperitoneally in group PC. Mice in group S2 were first administered orally as mice in group NC, and subsequently intraperitoneally administered E. coli O8 as mice in group PC. Compared with the NC group, mice in the PC group displayed clinical symptoms and pathological changes in the small intestine. Small intestine villi in the S2 group also developed some histologically pathological changes but not as severe as in the PC group. Moreover, there was less mortality in the S2 group than in the PC group. In PC group, thymus indexes, immunoglobulin A (IgA) in serum and Bifidobacterium in caecum were decreased and E. coli in the caecum was increased. In the S2 group, CD8+ of T lymphocyte subsets in blood and Bifidobacterium in caecum were decreased, while spleen indexes, IgG, IgM in serum, and CD3+ of T lymphocyte subsets in blood were increased. This suggests that S2 can relieve clinical symptoms of mice challenged with pathogenic E. coli O8, enhance their immune function, and influence their caecal microflora. The study will provide a theoretical foundation for utilizing antibacterial compound of S. cerevisiae from koumiss for curative purposes.


1998 ◽  
Vol 64 (7) ◽  
pp. 2624-2629 ◽  
Author(s):  
Laura Schick Zapanta ◽  
Takefumi Hattori ◽  
Magarita Rzetskaya ◽  
Ming Tien

ABSTRACT A Phanerochaete chrysosporium cDNA library was constructed in an expression vector that allows expression in bothEscherichia coli and Saccharomyces cerevisiae. This expression vector, λYES, contains the lacZ promoter for expression in E. coli and the GAL1 promoter for expression in yeast. A number of genes were cloned by complementation of bacterial amino acid auxotrophs. The cDNA encoding the β-isopropylmalate dehydrogenase from P. chrysosporiumwas characterized further. The genomic clone (gleu2) was subsequently isolated and was used successfully as a selectable marker to transform P. chrysosporium auxotrophs for LEU2. Protoplasts for transformation were prepared with readily obtained conidiospores rather than with basidiospores, which were used in previous P. chrysosporium transformation procedures. The method described here allows other genes to be isolated from P. chrysosporium for use as selectable markers.


Biology ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 358
Author(s):  
Ryan R. Cochrane ◽  
Stephanie L. Brumwell ◽  
Arina Shrestha ◽  
Daniel J. Giguere ◽  
Samir Hamadache ◽  
...  

Algae are attractive organisms for biotechnology applications such as the production of biofuels, medicines, and other high-value compounds due to their genetic diversity, varied physical characteristics, and metabolic processes. As new species are being domesticated, rapid nuclear and organelle genome engineering methods need to be developed or optimized. To that end, we have previously demonstrated that the mitochondrial genome of microalgae Phaeodactylum tricornutum can be cloned and engineered in Saccharomyces cerevisiae and Escherichia coli. Here, we show that the same approach can be used to clone mitochondrial genomes of another microalga, Thalassiosira pseudonana. We have demonstrated that these genomes can be cloned in S. cerevisiae as easily as those of P. tricornutum, but they are less stable when propagated in E. coli. Specifically, after approximately 60 generations of propagation in E. coli, 17% of cloned T. pseudonana mitochondrial genomes contained deletions compared to 0% of previously cloned P. tricornutum mitochondrial genomes. This genome instability is potentially due to the lower G+C DNA content of T. pseudonana (30%) compared to P. tricornutum (35%). Consequently, the previously established method can be applied to clone T. pseudonana’s mitochondrial genome, however, more frequent analyses of genome integrity will be required following propagation in E. coli prior to use in downstream applications.


1986 ◽  
Vol 6 (10) ◽  
pp. 3555-3558 ◽  
Author(s):  
M F Hoekstra ◽  
R E Malone

Unlike the DNA of higher eucaryotes, the DNA of Saccharomyces cerevisiae (bakers' yeast) is not methylated. Introduction of the Escherichia coli dam gene into yeast cells results in methylation of the N-6 position of adenine. The UV excision repair system of yeast cells specifically responds to the methylation, suggesting that it is capable of recognizing modifications which do not lead to major helix distortion. The UV repair functions examined in this report are involved in the incision step of pyrimidine dimer repair. These observations may have relevance to the rearrangements and recombination events observed when yeast or higher eucaryotic cells are transformed or transfected with DNA grown in E. coli.


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