scholarly journals Electroseparation of Slaughterhouse By-Product: Antimicrobial Peptide Enrichment by pH Modification

Membranes ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 90 ◽  
Author(s):  
Rémi Przybylski ◽  
Laurent Bazinet ◽  
Loubna Firdaous ◽  
Mostafa Kouach ◽  
Jean-François Goossens ◽  
...  
Keyword(s):  
Antimicrobial Peptide ◽  
Bioactive Peptides ◽  
Ultrafiltration Membrane ◽  
Natural Preservative ◽  
Ph Values ◽  
Peptide Concentration ◽  
Main Challenge ◽  
Efficient Alternative ◽  
Peptide Enrichment ◽  
Significant Concentration

The fractionation of bioactive peptides from hydrolysate is a main challenge to produce efficient alternative for synthetic additives. In this work, electrodialysis with ultrafiltration membrane (EDUF) was proposed to increase the purity of one antimicrobial peptide from slaughterhouse by-product hydrolysate. This targeted-peptide, α137–141 (653 Da, TSKYR), inhibits a large spectrum of microbial growths and delays meat rancidity; therefore, if concentrated, it could be used as food antimicrobial. In this context, three pH values were investigated during EDUF treatment to increase the α137–141 purity: 4.7, 6.5, and 9. pH 9 showed the highest purity increase—75-fold compared to the initial hydrolysate. Although the whole hydrolysate contains more than 100 peptides, only six peptides were recovered at a significant concentration. In this fraction, the α137–141 peptide represented more than 50% of the recovered total peptide concentration. The EDUF α137–141-enriched fraction obtained in this optimized condition would be a promising natural preservative to substitute synthetic additives used to protect food.

scholarly journals “Clicking” an Ionic Liquid to a Potent Antimicrobial Peptide: On the Route towards Improved Stability

2020 ◽  
Vol 21 (17) ◽  
pp. 6174
Author(s):  
Ana Gomes ◽  
Lucinda J. Bessa ◽  
Patrícia Correia ◽  
Iva Fernandes ◽  
Ricardo Ferraz ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Ionic Liquids ◽  
Klebsiella Pneumoniae ◽  
Antimicrobial Peptide ◽  
Clinical Isolate ◽  
Bioactive Peptides ◽  
Multidrug Resistant ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Improved Stability

A covalent conjugate between an antibacterial ionic liquid and an antimicrobial peptide was produced via “click” chemistry, and found to retain the parent peptide’s activity against multidrug-resistant clinical isolates of Gram-negative bacteria, and antibiofilm action on a resistant clinical isolate of Klebsiella pneumoniae, while exhibiting much improved stability towards tyrosinase-mediated modifications. This unprecedented communication is a prelude for the promise held by ionic liquids -based approaches as tools to improve the action of bioactive peptides.

Assembly of Nanoparticles from Bioactive Peptides and Chitosan

2011 ◽  
Vol 1312 ◽  
Author(s):  
B. Hu ◽  
Q. R. Huang ◽  
X. X. Zeng
Keyword(s):  
Electrophoretic Mobility ◽  
Bioactive Peptides ◽  
Molecular Chain ◽  
Mass Ratio ◽  
Ph Values ◽  
Transmission Electron ◽  
Low Salt ◽  
Liquid Chromatography Tandem Mass ◽  
Positively Charged ◽  
Critical Ph

ABSTRACTAssembly of nanoparticles from bioactive peptides, caseinophosphopeptides (CPPs) and chitosan (CS) at physiological conditions and various CS/CPPs mass ratios have been systematically studied using a combination of turbidimetric titration, dynamic light scattering (DLS), electrophoretic mobility (zeta-potential) and transmission electron microscopy (TEM). Peptides, incorporated with CS forming nanoparticles, have already been prepared and identified using liquid chromatography-tandem mass spectrometry (LC-MS-MS). They are characteristic with different amount of clusters of phosphorylated seryl residues. At low salt concentration, an increase of CS/CPP mass ratio shifted the critical pHϕ1, which designated the formation of CS/CPP nanocomplexes, as well as pHmax, representing the neutralization of positive and negative charge to higher pH values. The peptide-polymer binding mechanism was analyzed according to the results of DLS, electrophoretic mobility, and TEM. First, negatively charged CPPs absorbed to positively charged CS molecular chain to form intrapolymer nanocomplexes saturated with CPPs (CPPNP). Then, the negatively charged CPPNP was bridged by added positively charged CS. Finally, novel nano-scaled spherical brushes were formed as additional CS molecule absorbed back to and bound the CPPNP. Phosphorylated groups in the CPPs might be the dominant sites for interaction with –NH3+ on the CS molecular chain.

Separation of bioactive peptides by electrodialysis with ultrafiltration membrane

Desalination ◽  
2006 ◽  
Vol 200 (1-3) ◽  
pp. 620 ◽  
Author(s):  
Jean-François Poulin ◽  
Monica Araya-Farias ◽  
Jean Amiot ◽  
Laurent Bazinet
Keyword(s):  
Bioactive Peptides ◽  
Ultrafiltration Membrane

scholarly journals Behaviour of polysulfone ultrafiltration membrane for dyes removal

2018 ◽  
Vol 77 (8) ◽  
pp. 2093-2100 ◽  
Author(s):  
A. M. Hidalgo ◽  
M. Gómez ◽  
M. D. Murcia ◽  
M. Serrano ◽  
R. Rodríguez-Schmidt ◽  
...  
Keyword(s):  
Congo Red ◽  
Textile Industry ◽  
Rejection Rate ◽  
Ultrafiltration Membrane ◽  
Methyl Green ◽  
Permeate Flux ◽  
Separation Processes ◽  
Ph Values ◽  
Rejection Coefficient ◽  
Limited Application

Abstract Although ultrafiltration membranes have been used for the separation of macromolecules and colloids from solutions, this process has a limited application in the removal of dyes present in coloured discharges of textile industry, as these typically have much lower molecular weight than the molecular cut-off of the membranes (MWCO). In the present work, we have evaluated the behaviour of a polysulfone ultrafiltration membrane in the removal of different dyes from aqueous solutions (Congo red, methyl green and amaranth). Different variables (tangential flow rate, concentration of dye and pH of the feed) were studied to determine their influence on the separation processes (permeate flux and rejection coefficient). The results show that Congo red is easily removed with a GR60PP membrane (MWCO = 25 kDa), whereas methyl green and amaranth show rejection coefficient values of approximately 25.78% and 13.85%, respectively, at neutral pH. Also, an interesting effect is observed for the rejection coefficient for methyl green at different pH values. In addition, several treatments were performed to the membrane so as to modify its surface, trying to improve the values obtained for permeate flux and rejection rate.

Antimicrobial Activity of SPC13, New Antimicrobial Peptide Purified from Scolopendra polymorpha Venom

2020 ◽  
Vol 18 (3) ◽  
pp. 233-238
Author(s):  
Rodríguez-Alejandro C.I. ◽  
M.C. Gutiérrez
Keyword(s):  
Antimicrobial Activity ◽  
Antimicrobial Peptide ◽  
Broad Spectrum ◽  
Bioactive Peptides ◽  
Histone H3 ◽  
Bacteriostatic Activity ◽  
E Coli ◽  
Potential Source ◽  
Pharmacological Interest ◽  
Animal Venoms

Introduction: Currently animal venoms are considered a potential source of numerous bioactive peptides of biochemical and pharmacological interest, such as peptides with antithrombotic, anticoagulant and antimicrobial activity. Methods: Such is the case of the venom from the genus Scolopendromorpha, where numerous PAMs ranging from 2.5 to 4.4 kDa have been purified, they are broad spectrum isolates only of S. subspinipes mutilans. Results: In this study, an antimicrobial peptide (SPC13) of 13 kDa, present in the venom of Scolopendra polymorpha was purified by electroelution and presented antimicrobial activity against S. aureus and P. aeruginosa with MIC of 45 and 192.5 μg/ml respectively, as well as bacteriostatic activity against E. coli at a concentration of 155μg/ml. Conclusion: Additionally, this peptide has a 20.5% hemolytic activity. A partial sequence of SPC13 showed 98% identity with the histone H3 reported in S. viridis (GenkBank: DQ222181.1).

Antibacterial Protection by Enterocin AS-48 in Sport and Energy Drinks with Less Acidic pH Values

2009 ◽  
Vol 72 (4) ◽  
pp. 881-884 ◽  
Author(s):  
PILAR MARTINEZ VIEDMA ◽  
HIKMATE ABRIOUEL ◽  
NABIL BEN OMAR ◽  
ROSARIO LUCAS LÓPEZ ◽  
EVA VALDIVIA ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Pathogenic Bacteria ◽  
Dental Health ◽  
Energy Drinks ◽  
Low Ph ◽  
Final Concentration ◽  
Acidic Ph ◽  
Time Increase ◽  
Natural Preservative ◽  
Ph Values

The low pH and acid content found in sports and energy drinks are a matter of concern in dental health. Raising the pH may solve this problem, but at the same time increase the risks of spoilage or presence of pathogenic bacteria. In the present study, commercial energy drinks were adjusted to pH 5.0 and challenged with Listeria monocytogenes (drinks A to F), Staphylococcus aureus, Bacillus cereus, and Bacillus licheniformis (drink A) during storage at 37°C. L. monocytogenes was able to grow in drink A and survived in drinks D and F for at least 2 days. Addition of enterocin AS-48 (1 μg/ml final concentration) rapidly inactivated L. monocytogenes in all drinks tested. S. aureus and B. cereus also survived quite well in drink A, and were completely inactivated by 12.5 μg/ml enterocin AS-48 after 2 days of storage or by 25 μg/ml bacteriocin after 1 day. B. licheniformis was able to multiply in drink A, but it was completely inactivated by 5 μg/ml enterocin AS-48 after 2 days of storage or by 12.5 μg/ml bacteriocin after 1 day. Results from the present study suggest that enterocin AS-48 could be used as a natural preservative against these target bacteria in less acidic sport and energy drinks.

The significance of SEM in the diagnosis of haematopoietic malignancies

1978 ◽  
Vol 36 (2) ◽  
pp. 314-315
Author(s):  
Etienne de Harven ◽  
Nina Lampen
Keyword(s):  
Room Temperature ◽  
Culture Medium ◽  
Cell Attachment ◽  
Ethanol Dehydration ◽  
Moist Chamber ◽  
Efficient Alternative ◽  
Mononuclear Leucocytes ◽  
Fast Quenching ◽  
Freeze Dryer ◽  
Scanning Electron

Samples of heparinized blood, or bone marrow aspirates, or cell suspensions prepared from biopsied tissues (nodes, spleen, etc. ) are routinely prepared, after Ficoll-Hypaque concentration of the mononuclear leucocytes, for scanning electron microscopy. One drop of the cell suspension is placed in a moist chamber on a poly-l-lysine pretreated plastic coverslip (Mazia et al., J. Cell Biol. 66:198-199, 1975) and fifteen minutes allowed for cell attachment. Fixation, started in 2. 5% glutaraldehyde in culture medium at room temperature for 30 minutes, is continued in the same fixative at 4°C overnight or longer. Ethanol dehydration is immediately followed by drying at the critical point of CO2 or of Freon 13. An efficient alternative method for ethanol dehydrated cells is to dry the cells at low temperature (-75°C) under vacuum (10-2 Torr) for 30 minutes in an Edwards-Pearse freeze-dryer (de Harven et al., SEM/IITRI/1977, 519-524). This is preceded by fast quenching in supercooled ethanol (between -90 and -100°C).

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