The first latent green fluorophores for the detection of azoreductase activity in bacterial cultures

2013 ◽  
Vol 49 (78) ◽  
pp. 8815 ◽  
Author(s):  
Arnaud Chevalier ◽  
Claire Mercier ◽  
Laura Saurel ◽  
Sylvain Orenga ◽  
Pierre-Yves Renard ◽  
...  
Keyword(s):  
Bacterial Cultures ◽  
Azoreductase Activity

Dimerization of the Antimicrobial Peptide Polyphemusin I into One Polypeptide Chain: Theoretical and Practical Consequences

2019 ◽  
Vol 35 (5) ◽  
pp. 36-41
Author(s):  
V.A. Zenin ◽  
E.G. Sadykhov ◽  
A.N. Fedorov
Keyword(s):  
Antimicrobial Peptides ◽  
Pore Formation ◽  
Lipid Membrane ◽  
Polypeptide Chain ◽  
Unique Identifier ◽  
Bacterial Cultures ◽  
In Series ◽  
The Russian Federation ◽  
Peptide Dimerization ◽  
Putative Mechanism

A strategy of sequential dimerization of monomers of antimicrobial peptides (AMPs) into one polypeptide chain has been implemented on the example of a beta-structural AMP polyphemusin I which is one of the most effective candidate for use as an antibiotic. The possible polyphemusin I monomer and dimer structures in lipid membrane were studied in this work via molecular modeling. To this end, these molecules were chemically synthesized so that the dimer represented two monomers connected in series into one polypeptide chain with a flexible linker. The antimicrobial effects of monomer and dimer were then tested on various bacterial cultures, and their similarity was shown. Therefore, we can conclude that the pore formation is not a putative mechanism of the polyphemusin I action. antimicrobial peptides, peptide dimerization, mechanism of antimicrobial action, polyphemusin The work was supported by the Ministry of Science and Higher Education of the Russian Federation (Project Unique Identifier RFMEFI57517X0151).

Activated Sludge Exocellular Material Extraction Methods and Problems

1974 ◽  
Vol 9 (1) ◽  
pp. 250-261
Author(s):  
D.F. Carr ◽  
J. Ganczarczyk
Keyword(s):  
Activated Sludge ◽  
High Speed ◽  
Sewage Treatment ◽  
Dry Weight ◽  
Extraction Methods ◽  
Volatile Material ◽  
Bacterial Cultures ◽  
Volatile Solids ◽  
Pure Bacterial Cultures ◽  
Material Extraction

Abstract Activated sludge samples from two Toronto sewage treatment plants were subjected to the extraction of exocellular material by means of 9 different methods suggested for this purpose. Some of those methods, originally developed for pure bacterial cultures, were modified for the application to activated sludge. The amount of exocellular material obtained varied for Lakeview sludges from 0.4 to 3.2% of their dry volatile solids, and for Humber sludges from 0.3 to 5.3%. It has been found that extractions by the use of sulphuric acid, high-speed centrifugation and sodium hydroxide, were not suitable for the studied material. Especially surprising was the ineffectiveness of high-speed centrifugation to yield any measurable amounts of extract. The boiling water extraction is recommended for further studies on activated sludge exocellular material. The material extracted from activated sludge is very complex in nature. Generally more polysaccharide than protein was extracted, but the remaining volatile material may form up to 70% of the dry weight.

The effect of topical ophthalmic proparacaine, fluorescein, and tropicamide on subsequent bacterial cultures in healthy dogs

2021 ◽  
Author(s):  
Melanie A. Mironovich ◽  
Maria S. Mitchell ◽  
Chin‐Chi Liu ◽  
Renee T. Carter ◽  
Andrew C. Lewin
Keyword(s):  
Bacterial Cultures ◽  
Healthy Dogs

scholarly journals Antibiotics Modulate Intestinal Regeneration

Biology ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 236
Author(s):  
Lymarie M. Díaz-Díaz ◽  
Natalia Rosario-Meléndez ◽  
Andrea Rodríguez-Villafañe ◽  
Yariel Y. Figueroa-Vega ◽  
Omar A. Pérez-Villafañe ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Sea Cucumber ◽  
Regenerative Processes ◽  
Ecm Remodeling ◽  
Bacterial Cultures ◽  
Intestinal Regeneration ◽  
Negative Effect ◽  
Altered Cell ◽  
Holothuria Glaberrima ◽  
Mtt Assays

The increased antibiotics usage in biomedical and agricultural settings has been well documented. Antibiotics have now been shown to exert effects outside their purposive use, including effects on physiological and developmental processes. We explored the effect of various antibiotics on intestinal regeneration in the sea cucumber Holothuria glaberrima. For this, holothurians were eviscerated and left to regenerate for 10 days in seawater with different penicillin/streptomycin-based cocktails (100 µg/mL PS) including: 100 µg/mL kanamycin (KPS), 5 µg/mL vancomycin (VPS), and 4 µg/mL (E4PS) or 20 µg/mL (E20PS) erythromycin. Immunohistological and histochemical analyses were performed to analyze regenerative processes, including rudiment size, extracellular matrix (ECM) remodeling, cell proliferation, and muscle dedifferentiation. A reduction in muscle dedifferentiation was observed in all antibiotic-treated animals. ECM remodeling was decreased by VPS, E4PS, and E20PS treatments. In addition, organisms subjected to E20PS displayed a significant reduction in the size of their regenerating rudiments while VPS exposure altered cell proliferation. MTT assays were used to discard the possibility that the antibiotics directly affect holothurian metabolic activity while bacterial cultures were used to test antibiotic effects on holothurian enteric microbiota. Our results demonstrate a negative effect on intestinal regeneration and strongly suggest that these effects are due to alterations in the microbial community.

PRODUCTION OF CYTASES ACTIVE ON BARLEY GUM BY BACTERIA OF THE GENUS BACILLUS

1953 ◽  
Vol 31 (1) ◽  
pp. 28-32 ◽  
Author(s):  
A. C. Blackwood
Keyword(s):  
Bacillus Subtilis ◽  
Enzymatic Activity ◽  
Nitrogen Source ◽  
Freeze Drying ◽  
Shake Flask ◽  
Sole Nitrogen Source ◽  
Genus Bacillus ◽  
Original Activity ◽  
Bacterial Cultures ◽  
Bacillus Genus

One hundred and fourteen bacterial cultures representing most of the species in the Bacillus genus were tested for the production of extracellular barley gum cytase. Assays were made on shake-flask cultures grown on a medium containing glucose and yeast extract. Although all the organisms had some enzymatic activity, certain strains of Bacillus subtilis gave the best yields of cytase. On a medium with asparagine as the sole nitrogen source even higher yields were obtained. The crude cytase preparations were stable and after freeze-drying most of the original activity remained.

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