Biochemical and Physical Changes in Shaken Suspensions of Pasteurella Pestis

Wessman, G. E.; Miller, Donna J.

doi:10.21236/ad0481042

Cited by 3 publications

(3 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Floc formation from other types of polymer should also be considered. Wessman and Miller (23) found that clumping of Pasteurella pestis was caused by the polymerization of extracellular nucleic acids that were excreted by the cells. The role of PHB reported by Crabtree et al (6) should also be further considered as an explanation of bacterial flocculation.…”

Section: Discussionmentioning

confidence: 99%

Structure of Exocellular Polymers and Their Relationship to Bacterial Flocculation

et al. 1969

View full text Add to dashboard Cite

Several gram-negative, polarly flagellated rods were isolated on the basis of their flocculent growth habit. Some of the isolates possessed a capsular matrix which is composed of exocellular fibrils. Other isolates did not appear to have a capsular matrix when examined with a bright-field microscope with or without the aid of stains. However, these latter type isolates did possess exocellular material which can be demonstrated by adsorption of a fluorescent dye under an ultraviolet microscope. Electron microscopic examination demonstrated that the exocellular material around all isolates examined is fibrillar. The fibrils were susceptible to cellulase although all fibrils did not appear to be identical. It is postulated that the exocellular polymers were responsible for the flocculent growth habit of the bacteria, and that the process of bacterial flocculation produced by synthetic polyelectrolytes was essentially the same as that caused by naturally produced exopolymers.

show abstract

Section: Discussionmentioning

confidence: 99%

Structure of Exocellular Polymers and Their Relationship to Bacterial Flocculation

et al. 1969

View full text Add to dashboard Cite

show abstract

“…11 2004 cans and Vibrio costicolus growing in nutritionally defi cient media, DNA plays a role of connector: it is secreted into the medium to maintain cell aggregates [55]. A sim ilar phenomenon was described in Pasteurella (Yersinia) pestis [56]. The cells of Staphylococcus aureus secrete excessive amounts of RNA and proteins participating in cell aggregation [57].…”

Section: Cell-cell Interactions Mediated By Physical Factors (Intercementioning

confidence: 99%

Vacuolar Na+/H+ antiporter from barley: identification and response to salt stress

Vasekina

Yershov²,

Reshetova³

et al. 2005

Biochemistry (Moscow)

View full text Add to dashboard Cite

One of the protective mechanisms used by plants to survive under conditions of salt stress caused by high NaCl concentration is the removal of Na+ from the cytoplasm. This mechanism involves a number of Na+/H+-antiporter proteins that are localized in plant plasma and vacuolar membranes. Due to the driving force of the electrochemical H+ gradient created by membrane H+-pumps (H+-ATPases and vacuolar H+-pyrophosphatases), Na+/H+-antiporters extrude sodium ions from the cytoplasm in exchange for protons. In this study, we have identified the gene for the barley vacuolar Na+/H+-antiporter HvNHX2 using the RACE (rapid amplification of cDNA ends)-PCR (polymerase chain reaction) technique. It is shown that the identified gene is expressed in roots, stems, and leaves of barley seedlings and that it presumably encodes a 59.6 kD protein composed of 546 amino acid residues. Antibodies against the C-terminal fragment of HvNHX2 were generated. It is shown that the quantity of HvNHX2 in tonoplast vesicles isolated from roots of barley seedlings remains the same, whereas the rate of Na+/H+ exchange across these membranes increases in response to salt stress. The 14-3-3-binding motif Lys-Lys-Glu-Ser-His-Pro (371-376) was detected in the HvNHX2 amino acid sequence, which is suggestive of possible involvement of the 14-3-3 proteins in the regulation of HvNHX2 function.

show abstract

“…Floc formation would be caused by these polymers, and treatment with a suitable exopolymer-degrading enzyme would cause deflocculation of the floc. In pure culture, there are many bacteria that form flocs susceptible to cellulase and some that form flocs susceptible to protease or deoxyribonuclease (1, 3,6,9,13,17). The natural floc of activated sludge, however, could not be entirely deflocculated by these enzymes (11).…”

mentioning

confidence: 99%

Exocellular mucopolysaccharide closely related to bacterial floc formation

Tago¹,

Aida²

1977

Appl Environ Microbiol

View full text Add to dashboard Cite

A bacterium isolated from activated sludge formed a visible floc and also produced an exoenzyme that could bring about deflocculation. Scanning electron microscopic examination revealed that the cells were embedded in a film mesh in the floc, which disappeared after treatment with the deflocculating enzyme. Polysaccharides isolated from the floc were fractionated into three fractions by diethylaminoethyl-Sephadex A-25 column chromatography, whereas those from the free cells were fractionated into only two fractions. The missing fraction was a mucopolysaccharide composed of glucosamine, glucose, mannose, galactose, and rhamnose and was hydrolyzed to oligosaccharides by the deflocculating enzyme. The other two fractions were resistant to the enzyme. These results show that the mesh structure of the floc is dependent on a mucopolysaccharide hydrolyzed by the deflocculating enzyme.

show abstract

Biochemical and Physical Changes in Shaken Suspensions of Pasteurella Pestis

Cited by 3 publications

References 4 publications

Structure of Exocellular Polymers and Their Relationship to Bacterial Flocculation

Structure of Exocellular Polymers and Their Relationship to Bacterial Flocculation

Vacuolar Na+/H+ antiporter from barley: identification and response to salt stress

Exocellular mucopolysaccharide closely related to bacterial floc formation

Contact Info

Product

Resources

About