scholarly journals Effect of Different Carbon Sources on Bacterial Nanocellulose Production and Structure Using the Low pH Resistant Strain Komagataeibacter Medellinensis

Materials ◽  
2017 ◽  
Vol 10 (6) ◽  
pp. 639 ◽  
Author(s):  
Carlos Molina-Ramírez ◽  
Margarita Castro ◽  
Marlon Osorio ◽  
Mabel Torres-Taborda ◽  
Beatriz Gómez ◽  
...  
Keyword(s):  
Resistant Strain ◽  
Carbon Sources ◽  
Low Ph ◽  
Bacterial Nanocellulose

Thermophilic Bacterial Exopolysaccharides

2022 ◽  
pp. 334-361
Author(s):  
Rakesh Goswami ◽  
Bidyut Bandyopadhyay ◽  
Sanjoy Sadhukhan
Keyword(s):  
Hydrothermal Vents ◽  
Extracellular Polymeric Substances ◽  
Hot Spring ◽  
Carbon Sources ◽  
Extreme Environments ◽  
Value Added ◽  
Low Ph ◽  
Extreme Conditions ◽  
Biotechnological Applications ◽  
Bacterial Exopolysaccharides

Bacterial exopolysaccharides have enormous diversity with valuable characteristics, synthesized by various pathways in extreme conditions like salinity, geothermal springs, or hydrothermal vents. Due to extreme environments, these microorganisms have various adaption principles (e.g., low pH, high temperature, high saltation, and high radiation). Exopolysaccharide is an organic compound produced by most bacteria during fermentation using various carbon sources, resulting in a jelly-like or mass network structure outside the cell wall. This biopolymer has an adherent cohesive layer throughout the cell layer. Hot spring bacterial polysaccharides contain diverse extracellular polymeric substances. With a gain in popularity in applications of thermophilic microbial polysaccharides and its demand in diverse value-added industrial products, this chapter aims to provide valuable information on the physicochemical function and biotechnological applications in the field of food, medical imaging, nano-drugs, bioremediation, cancer, anti-bacterial, tissue engineering, etc.

Relations between resistance to chloroquine and acidification of endocytic vesicle of Plasmodium berghei

Parasitology ◽  
1989 ◽  
Vol 98 (1) ◽  
pp. 1-6 ◽  
Author(s):  
J. Mahmalgi ◽  
E. Veignie ◽  
G. Prensier ◽  
S. Moreau
Keyword(s):  
Plasmodium Berghei ◽  
Resistant Strain ◽  
Low Ph ◽  
Chloroquine Resistance ◽  
Acidic Ph ◽  
Endocytic Vesicle ◽  
Complementary Method ◽  
Endocytic Vesicles ◽  
Acidic Compartments

SummaryIn order to visualize low-pH compartments of Plasmodium berghei strains we have used a basic congener of dinitrophenol, 3-(2,4-dinitroanilino)-3'-amino-N-methyldipropylamine (DAMP) which concentrates in acidic compartments, and can be detected by immunocytochemistry with anti-dinitrophenol antibodies. We have demonstrated that in a P. berghei chloroquine-sensitive strain (N strain), DAMP accumulates in the endocytic vacuoles where haemoglobin degradation is occurring. These compartments which have recently been shown to concentrate 4-aminoquinoline drugs (Moreau, Prensier, Maalla & Fortier, 1986) have an acidic pH. Conversely DAMP was found scattered all over the cytoplasm in a P. berghei chloroquine-resistant strain; the same phenomenon was previously observed (Moreau et al. 1986) in the localization of a 4-aminoquinoline on this same strain. Monensin-induced swelling of acidic compartments (Boss & Morre, 1984) was used as a complementary method for the determination of low-pH compartments on P. berghei strains. All the data reported here suggest that chloroquine resistance in P. berghei RC may be related to an impairment in the acidification of endocytic vesicles.

scholarly journals Effects of Dissolved Sulfide, pH, and Temperature on Growth and Survival of Marine Hyperthermophilic Archaea

2005 ◽  
Vol 71 (10) ◽  
pp. 6383-6387 ◽  
Author(s):  
Karen G. Lloyd ◽  
Virginia P. Edgcomb ◽  
Stephen J. Molyneaux ◽  
Simone Böer ◽  
Carl O. Wirsen ◽  
...  
Keyword(s):  
Hydrothermal Vent ◽  
Carbon Sources ◽  
Low Ph ◽  
Electron Donors ◽  
Hyperthermophilic Archaea ◽  
Sulfide Concentration ◽  
Growth And Survival ◽  
Dissolved Sulfide ◽  
Close Relatives ◽  
High Sulfide

ABSTRACT The ability of metabolically diverse hyperthermophilic archaea to withstand high temperatures, low pHs, high sulfide concentrations, and the absence of carbon and energy sources was investigated. Close relatives of our study organisms, Methanocaldococcus jannaschii, Archaeoglobus profundus, Thermococcus fumicolans, and Pyrococcus sp. strain GB-D, are commonly found in hydrothermal vent chimney walls and hot sediments and possibly deeper in the subsurface, where highly dynamic hydrothermal flow patterns and steep chemical and temperature gradients provide an ever-changing mosaic of microhabitats. These organisms (with the possible exception of Pyrococcus strain GB-D) tolerated greater extremes of low pH, high sulfide concentration, and high temperature when actively growing and metabolizing than when starved of carbon sources and electron donors/acceptors. Therefore these organisms must be actively metabolizing in the hydrothermal vent chimneys, sediments, and subsurface in order to withstand at least 24 h of exposure to extremes of pH, sulfide, and temperature that occur in these environments.

Relationship between golgi apparatus and axonal reticulum in sympathetic ganglion cells

1978 ◽  
Vol 36 (2) ◽  
pp. 598-599
Author(s):  
J. Quatacker ◽  
W. De Potter
Keyword(s):  
Golgi Apparatus ◽  
Sympathetic Ganglion ◽  
Phosphotungstic Acid ◽  
Ganglion Cells ◽  
Low Ph ◽  
Dense Core ◽  
Dense Core Vesicles ◽  
Large Dense Core Vesicles ◽  
Cervical Ganglia ◽  
Axoplasmic Reticulum

Mucopolysaccharides have been demonstrated biochemically in catecholamine-containing subcellular particles in different rat, cat and ox tissues. As catecholamine-containing granules seem to arise from the Golgi apparatus and some also from the axoplasmic reticulum we examined wether carbohydrate macromolecules could be detected in the small and large dense core vesicles and in structures related to them. To this purpose superior cervical ganglia and irises from rabbit and cat and coeliac ganglia and their axons from dog were subjected to the chromaffin reaction to show the distribution of catecholamine-containing granules. Some material was also embedded in glycolmethacrylate (GMA) and stained with phosphotungstic acid (PTA) at low pH for the detection of carbohydrate macromolecules.The chromaffin reaction in the perikarya reveals mainly large dense core vesicles, but in the axon hillock, the axons and the terminals, the small dense core vesicles are more prominent. In the axons the small granules are sometimes seen inside a reticular network (fig. 1).

Mechanism of Human Plasminogen Activation by Streptokinase and Human Plasmin

1964 ◽  
Vol 11 (01) ◽  
pp. 085-093
Author(s):  
W. F Blatt ◽  
JL Gray ◽  
H Jensen
Keyword(s):  
Proteolytic Activity ◽  
Low Ph ◽  
Plasminogen Activation ◽  
Sensitive Tool ◽  
Human Plasminogen

SummaryA sensitive tool has been described for measuring fibrinolysis in reconstituted systems using thrombelastography. Activator mixtures with no appreciable proteolytic activity can similarly be tested in this system when the fibrinogen utilized has sufficient plasminogen present. Exposure of human plasminstreptokinase mixtures formed at pH 7.0 to acid conditions produced a striking loss of activator activity which could not be ascribed to low pH lability of the components, nor to plasmin action on the SK at pH 2.0. This is additional evidence for the hypothesis that human plasmin interacts with SK to form a complex capable of converting human and bovine plasminogen to plasmin.

Influence of Polymer Charge, Temperature, and Surfactants on Surface Sizing of Liner and Greaseproof Paper With Hydrophobically Modified Starch

TAPPI Journal ◽  
2009 ◽  
Vol 8 (2) ◽  
pp. 33-38 ◽  
Author(s):  
ANNA JONHED ◽  
LARS JÄRNSTRÖM
Keyword(s):  
Phase Separation ◽  
Contact Angles ◽  
Low Ph ◽  
Hydrophobically Modified ◽  
Paper Sizing ◽  
Surface Sizing ◽  
Separation Temperature ◽  
Hydrophobic Nature ◽  
Sizing Agents ◽  
Charge Temperature

The aim of this study was to investigate the properties of hydrophobically modified (HM) quaterna-ry ammonium starch ethers for paper sizing. These starches possess temperature-responsive properties; that is, gelation or phase separation occurs at a certain temperature upon cooling. This insolubility of the HM starches in water at room temperature improved their performance as sizing agents. The contact angles for water on sized liner were substantially larger than on unsized liner. When the application temperature was well above the critical phase-separation temperature, larger contact angles were obtained for liner independently of pH compared with those at the lower application temperature. Cobb60 values for liner decreased upon surface sizing, with a low pH and high application temperature giving lower water penetration. Contact angles on greaseproof paper decreased upon sur-face sizing as compared to unsized greaseproof paper, independently of pH and temperature. Greaseproof paper showed no great difference between unsized substrates and substrates sized with HM starch at different pH. This is probably due to the already hydrophobic nature of greaseproof paper. However, the Cobb60 values increased at low pH and low application temperature. Surfactants were added to investigate how they affect the sized surface. Addition of surfactant reduces the contact angles, in spite of indications of complex formation.

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