Factors influencing the in vivo stability of L-serine deaminase activity in E. coli K12

1978 ◽  
Vol 24 (12) ◽  
pp. 1607-1613
Author(s):  
R. D. Beeraj ◽  
J. F. Morris ◽  
E. B. Newman
Keyword(s):  
Enzyme Activity ◽  
Nitrogen Source ◽  
Inorganic Nitrogen ◽  
Intact Cells ◽  
Inorganic Nitrogen Source ◽  
E Coli ◽  
Organic Nitrogen Source ◽  
Serine Deaminase ◽  
In Cells

L-Serine deaminase (L-SD) is unstable in intact cells of Escherichia coli K12. The extent of this instability is dependent on the nitrogen content of the medium in which the enzyme is synthesized, and on that in which it is tested. Enzyme activity in cells grown with an inorganic nitrogen source is unstable in the presence of inorganic nitrogen; enzyme activity in cells grown with an organic nitrogen source is unstable in the presence of the amino acids glycine and leucine.

Parallel determination of enzyme activities and in vivo fluxes in Brassica napus embryos grown on organic or inorganic nitrogen source

2007 ◽  
Vol 68 (16-18) ◽  
pp. 2232-2242 ◽  
Author(s):  
Björn H. Junker ◽  
Joachim Lonien ◽  
Lindsey E. Heady ◽  
Alistair Rogers ◽  
Jörg Schwender
Keyword(s):  
Brassica Napus ◽  
Nitrogen Source ◽  
Enzyme Activities ◽  
Inorganic Nitrogen ◽  
Inorganic Nitrogen Source

Stimulation of dextranase production by oxidized dextran

1970 ◽  
Vol 16 (9) ◽  
pp. 841-844 ◽  
Author(s):  
Robert G. Brown
Keyword(s):  
Carbon Source ◽  
Nitrogen Source ◽  
Enzyme Production ◽  
Inorganic Nitrogen ◽  
Penicillium Funiculosum ◽  
Inorganic Nitrogen Source ◽  
Oxidized Dextran ◽  
Excess Glucose ◽  
Stimulation Of

Penicillium funiculosum, Penicillium lilacinum, and Spicaria violacea produced excellent yields of dextranase if ketodextran replaced dextran as a carbon source. Ketodextrans I and II having degrees of substitution of 2 and 20% respectively were used in this study. P. funiculosum grew equally well on dextran and ketodextran I but less well on ketodextran II. Addition of a readily metabolizable carbohydrate such as glucose, sucrose, or galactose stimulated growth on ketodextran II, resulting in better dextranase production. However, excess glucose reversed this increase in enzyme production. Replacement of an inorganic nitrogen source with an organic one further stimulated dextranase production during growth of P. funiculosum on ketodextran II.

Bacterial in-cell NMR of human α-synuclein: a disordered monomer by nature?

2012 ◽  
Vol 40 (5) ◽  
pp. 950-954 ◽  
Author(s):  
Andres Binolfi ◽  
Francois-Xavier Theillet ◽  
Philipp Selenko
Keyword(s):  
Escherichia Coli ◽  
Protein Structure ◽  
Intracellular Protein ◽  
E Coli ◽  
Intrinsically Disordered ◽  
Escherichia Coli Cells ◽  
Rule Out ◽  
In Cells

The notion that human α-synuclein is an intrinsically disordered monomeric protein was recently challenged by a postulated α-helical tetramer as the physiologically relevant protein structure. The fact that this alleged conformation had evaded detection for so many years was primarily attributed to a widely used denaturation protocol to purify recombinant α-synuclein. In the present paper, we provide in-cell NMR evidence obtained directly in intact Escherichia coli cells that challenges a tetrameric conformation under native in vivo conditions. Although our data cannot rule out the existence of other intracellular protein states, especially in cells of higher organisms, they indicate clearly that inside E. coli α-synuclein is mostly monomeric and disordered.

scholarly journals In vivocloning of β 1-4 endoglucanase gene ofSerratia liquefaciensusing Muduction and itsin silicoanalysis

2018 ◽  
Author(s):  
S. Gowri Sankar ◽  
J. Asnet Mary ◽  
S. John Vennison ◽  
A. Alwin Prem Anand
Keyword(s):  
Enzyme Activity ◽  
Active Site ◽  
Plant Cell Wall ◽  
Central Axis ◽  
Nucleotide Sequence Analysis ◽  
Cellulolytic Bacterium ◽  
E Coli ◽  
Endoglucanase Gene ◽  
Major Structural Component

AbstractCellulose is the major structural component in the plant cell wall. The bio-degradation of cellulose molecules is facilitated by cellulase. In the present study,in vivocloning of cellulase (β-1, 4 endoglucanase) gene from a cellulolytic bacteriumSerratia liquefaciensintoE. coliDH5α has been performed using mini-Mu phage transduction. The enzyme activity of cloned endoglucanase was 81.2U/mg at optimum temperature (40°C) and 80.2U/mg at optimum pH7, while the wildtype has 65.9U/mg and 64.9U/mg respectively. The conserved domain analysis shows thatS. liquefaciensendoglucanase belongs to GH8 family. The nucleotide sequence analysis of wildtype and cloned endoglucanase shows that mutations were found at residues 51(Lys - Asn), 203(Trp-Cys), 246(Thr-Iso), 260(Gly-Ala) and 288(Phe-Leu). The structural analysis shows the active site of wildtype endoglucanase is a narrow groove which lies parallel to the central axis, whereas cloned endoglucanase is broad and tilted to ∼70° from the central axis. The increased enzyme activity in the cloned endoglucanase is due to the structural modification conferred by changes in amino acid resulting in widening of the cleft in the active site.

scholarly journals Production of high cellulase yields from polypore fungi in solid-state fermentation using green tea waste

2019 ◽  
Author(s):  
KA Nguyen ◽  
W Penkhrue ◽  
S Lumyong
Keyword(s):  
Solid State ◽  
Nitrogen Source ◽  
Green Tea ◽  
Solid State Fermentation ◽  
Incubation Temperature ◽  
Ph Value ◽  
Inorganic Nitrogen ◽  
Inorganic Nitrogen Source ◽  
Tea Waste ◽  
Optimal Medium

AbstractPolypores are diverse macrofungi that have been extensively studied for their enzyme production capabilities. Presently, these enzymes are being used for many industrial purposes. However, the high-cost associated with their production is the main barrier to their broader application. This work aimed to study the optimal medium and conditions by using solid state fermentation. Seven polypore strains were used for cellulase activity screening. The fermentation experiments were carried out in 250 mL Erlenmeyer flasks with green tea waste as a substrate. Notably, Microporus sp. KA038 showed the best level of activity of 81.8 IU/gds. Various parameters such as temperature on growth, moisture content, nitrogen source, initial pH value, inoculum size and incubation time were considered to determine the optimal conditions for cellulase production. The optimal medium consisted of green tea leaves as a carbon source, beef extract as an organic nitrogen source, and NH4H2PO4 as an inorganic nitrogen source, while pH 7.0 and an incubation temperature of 30°C for 4 days resulted in a high enzyme yield with Microporus sp. KA038.

Effect of Ammonium Sulphate on the Sporulation of Bacillus thuringiensis subsp. aizawai SN2 (a Local Isolate) during Batch Fermentation

2012 ◽  
Author(s):  
Wan Mohtar Wan Yusoff ◽  
Mohd. Mazmira Mohd. Masri ◽  
Choy Mei Chan
Keyword(s):  
Bacillus Thuringiensis ◽  
Nitrogen Content ◽  
Key Words ◽  
Nitrogen Source ◽  
Ammonium Sulphate ◽  
Batch Fermentation ◽  
Inorganic Nitrogen ◽  
Inorganic Nitrogen Source ◽  
Initial Concentration ◽  
Bacillus Thuringiensis Subsp

Kesan penambahan ammonium sulfat, (NH4)2SO, (sebagai sumber nitrogen bukan organik tunggal) terhadap pensporaan Bacillus thuringiensis subsp. aizawai strain SN2 dalam kultur kelompok telah dikaji. Peratus spora tertinggi (76 %) dikesan selepas 96 j pengkulturan dalam medium yang mengandungi 1.5 gL-1 (NH4)2SO4. Peratus spora tertinggi sebanyak 82 % juga dikesan dalam sampel 96 j apabila medium yang mengandungi 1.5 gL-1 (NH4)2SO4 ditambah dengan 3.0 gL-1 (NH4)2SO4 pada jam keenam selepas mula fermentasi. Peningkatan peratus spora didapati tidak berkaitan dengan jumlah kandungan nitrogen tetapi berkaitan dengan masa penambahan sumber nitrogen. Kata kunci: Bacillus thuringiensis subsp. aizawai strain SN2, masa penambahan nutrien, kultur kelompok The effect of ammonium sulphate (as the sole inorganic nitrogen source) on the sporulation of Bacillus thuringiensis subsp. aizawai strain SN2 was investigated in batch fermentation. The spore percentage of 76 % was achieved at 96 h after inoculation into a medium containing initial cencentration of 1.5 gL-1 ammonium sulphate. In another experiment, the maximum spore percentage of 82 % was obtained after 96 h inoculation in a medium with initial concentration of 1.5 gL-1 (NH4)2SO4 followed by an addition of 3.0 gL-1 (NH4)2SO4 after 6 h of fermentation. The increase in Bacillus thuringiensis spore percentage was not a function of total nitrogen content in the medium but was a function of the time nitrogen being added. Key words: Bacillus thuringiensis subsp. aizawai strain SN2, timing addition, batch fermentation

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