Isolation and partial chemical analysis of firmly bound exopolysaccharide from adherent cells of a freshwater sediment bacterium

1985 ◽  
Vol 31 (8) ◽  
pp. 675-680 ◽  
Author(s):  
R. M. Platt ◽  
G. G. Geesey ◽  
J. D. Davis ◽  
D. C. White
Keyword(s):  
Chemical Analysis ◽  
Ultrastructural Level ◽  
Freshwater Sediment ◽  
Culture Vessel ◽  
Adherent Cells ◽  
Natural Sediment ◽  
Bacterial Populations ◽  
Glucose 6 Phosphate Dehydrogenase ◽  
Wall Components ◽  
Partial Chemical

Cells of a freshwater sediment bacterium produced firmly bound extracellular polymers in laboratory cultures which, at the ultrastructural level, resembled those produced by natural sediment bacterial populations. Production of the exopolymers during subculture was maintained by using as a source of inoculum the population of cells which adhered to each other and to the wall of the glass culture vessel. The exopolymers were selectively released from the cells by blending and centrifugation in the presence of EDTA. Evaluation of glucose-6-phosphate dehydrogenase activity and 2-keto-3-deoxyoctonate concentration indicated that only small amounts of intracellular and cell wall components were released from the cells during exopolymer removal. Chemical analysis of the isolated crude exopolymer material indicated that it contained protein, polysaccharide, and DNA. The treatment promoted the selective isolation of firmly bound polymers from the surface of adherent cells.

scholarly journals Comparison of the Levels of Bacterial Diversity in Freshwater, Intertidal Wetland, and Marine Sediments by Using Millions of Illumina Tags

2012 ◽  
Vol 78 (23) ◽  
pp. 8264-8271 ◽  
Author(s):  
Yu Wang ◽  
Hua-Fang Sheng ◽  
Yan He ◽  
Jin-Ya Wu ◽  
Yun-Xia Jiang ◽  
...  
Keyword(s):  
Marine Sediments ◽  
Marine Sediment ◽  
Bacterial Communities ◽  
Principal Component ◽  
Freshwater Sediment ◽  
Intertidal Sediment ◽  
Taxon Richness ◽  
Natural Sediment ◽  
Content Type ◽  
Intertidal Wetland

ABSTRACTSediment, a special realm in aquatic environments, has high microbial diversity. While there are numerous reports about the microbial community in marine sediment, freshwater and intertidal sediment communities have been overlooked. The present study determined millions of Illumina reads for a comparison of bacterial communities in freshwater, intertidal wetland, and marine sediments along Pearl River, China, using a technically consistent approach. Our results show that both taxon richness and evenness were the highest in freshwater sediment, medium in intertidal sediment, and lowest in marine sediment. The high number of sequences allowed the determination of a wide variety of bacterial lineages in all sediments for reliable statistical analyses. Principal component analysis showed that the three types of communities could be well separated from phylum to operational taxonomy unit (OTU) levels, and the OTUs from abundant to rare showed satisfactory resolutions. Statistical analysis (LEfSe) demonstrated that the freshwater sediment was enriched withAcidobacteria,Nitrospira,Verrucomicrobia,Alphaproteobacteria, andBetaproteobacteria. The intertidal sediment had a unique community with diverse primary producers (such asChloroflexi,Bacillariophyta,Gammaproteobacteria, andEpsilonproteobacteria) as well as saprophytic microbes (such asActinomycetales,Bacteroidetes, andFirmicutes). The marine sediment had a higher abundance ofGammaproteobacteriaandDeltaproteobacteria, which were mainly involved in sulfate reduction in anaerobic conditions. These results are helpful for a systematic understanding of bacterial communities in natural sediment environments.

scholarly journals Comparative Dynamics of Adherent and Nonadherent Bacterial Populations on Maize Leaves

2002 ◽  
Vol 92 (9) ◽  
pp. 1015-1023 ◽  
Author(s):  
Gwyn A. Beattie ◽  
Lise M. Marcell
Keyword(s):  
Pseudomonas Syringae ◽  
Bacterial Species ◽  
Bacterial Adherence ◽  
Cuticular Wax ◽  
Adherent Cells ◽  
Clavibacter Michiganensis ◽  
Bacterial Populations ◽  
Clavibacter Michiganensis Subsp ◽  
Maize Leaves ◽  
Survival And Growth

The dynamics of the adherent and nonadherent populations of three bacterial species on maize leaves were examined to identify the extent to which bacteria adhere to leaves and the importance of this adhesion to leaf colonization. Pantoea agglomerans strain BRT98, Clavibacter michiganensis subsp. nebraskensis strain GH2390, and Pseudomonas syringae pv. syringae strain HS191R all rapidly adhered to maize leaves following inoculation, but differed in the percentage of cells that adhered to the leaves. Immediately following inoculation, the percentage of adherent cells was highest for the saprophyte P. agglomerans (8 to 10%) and was much lower for the pathogens C. michiganensis subsp. nebras-kensis and P. syringae pv. syringae (2 to 3 and <1%, respectively), although the results for P. syringae pv. syringae HS191R were based on only one experiment. In the 4 days following inoculation, the percentage of the P. agglomerans populations that adhered to the leaves increased to approximately 70%. Similarly, the percentage of C. michiganensis subsp. nebraskensis and P. syringae pv. syringae cells that resisted removal steadily increased in the days following inoculation, although these increases probably reflected both adherence and localization to endophytic sites. Based on differences in the percentage of cells adhering to several cuticular wax mutants of maize, the rapid adherence of C. michiganensis subsp. nebraskensis cells to maize leaves was influenced by the cuticular wax properties, while the rapid adherence of P. agglomerans was not. Finally, bacterial adherence to leaves was advantageous to P. agglomerans survival and growth on leaves based on the finding that the nonadherent populations of the P. agglomerans strain decreased significantly more than did the adherent populations in the 24 h following inoculation, and increased much less than did the adherent populations over the next 3 days. Similar results with the C. michiganensis subsp. nebraskensis and P. syringae pv. syringae strains indicate that bacterial adherence to leaves, bacterial movement to endophytic sites, or both were advantageous to the survival and growth of these strains on leaves.

Some Observations on the Formation of Wollastonite from Calcite and Quartz

1971 ◽  
Vol 8 (7) ◽  
pp. 844-851 ◽  
Author(s):  
T. M. Gordon
Keyword(s):  
Electron Microscope ◽  
Reaction Mechanism ◽  
Chemical Analysis ◽  
Scanning Electron Microscope ◽  
Thin Layer ◽  
Total Pressure ◽  
Initial Period ◽  
Experimental Scatter ◽  
Partial Chemical ◽  
Scanning Electron

Mixtures of powdered calcite and quartz were reacted for various lengths of time at a total pressure of 2000 bars, 650 °C, in an H2O–CO2 fluid. Extent of formation of wollastonite was determined by partial chemical analysis of run products. Experimental scatter precludes detailed analysis of the reaction mechanism.The data show that approximately 40% reaction takes place in the first 24 h, and that after this initial period the rate decreases. Examination of run products shows the calcite to be surrounded by radiating wollastonite crystals. This suggests that the wollastonite cover forms during the initial stages of reaction and, by shielding the calcite, suppresses the reaction.Single cleavage flakes of calcite were packed in −325 mesh quartz and allowed to react under the same conditions as the powders. A scanning electron microscope was used to examine and photograph the fragment surfaces at the conclusion of the experiments.Examination of the photographs shows the calcite to be completely covered with a thin layer of wollastonite crystals. Details of the morphology suggest that the wollastonite grew outward from nucleation centers and that the solution of calcite and quartz may have been accelerated near growing wollastonite. Although no details of the reaction mechanism can be deduced, the model favored here is that growth was most rapid near the calcite–wollastonite interface and the mantling effect slowed the reaction by preventing the transport of silica to the calcite surface.

Purification and partial chemical analysis of Sindbis virus

Virology ◽  
1963 ◽  
Vol 20 (3) ◽  
pp. 433-445 ◽  
Author(s):  
E.R. Pfefferkorn ◽  
Hilda Salmon Hunter
Keyword(s):  
Chemical Analysis ◽  
Sindbis Virus ◽  
Partial Chemical

ON THE ROTIFERA AND LIMNOLOGY OF AN HUNGARIAN BOG POND

1962 ◽  
Vol 40 (5) ◽  
pp. 677-684 ◽  
Author(s):  
Thomas F. Nogrady
Keyword(s):  
New Species ◽  
Chemical Analysis ◽  
Two New Species ◽  
Partial Chemical

The results of a brief survey of the limnology of an Hungarian bog pond and a partial chemical analysis of the water are given. The Rotifera, Gastrotricha, Cladocera, and Copepoda, found between June and October, are given, and some of the Rotifera and two new species (Cephalodella conica and Lecane urna) are described.

Evidence for a physiological gradient in the vestimentiferan trophosome: size–frequency analysis of bacterial populations and trophosome chemistry

1986 ◽  
Vol 64 (5) ◽  
pp. 1095-1103 ◽  
Author(s):  
M. E. de Burgh
Keyword(s):  
Chemical Analysis ◽  
Frequency Analysis ◽  
Hydrothermal Vents ◽  
Bacterial Symbiont ◽  
Posterior Region ◽  
Bacterial Symbionts ◽  
Bacterial Populations ◽  
Minor Elements ◽  
Bacterial Division ◽  
Bulk Chemical

Size of bacterial symbionts was compared in anterior and posterior trophosome tissue of four vestimentiferan worm species from hydrothermal vents. Analysis of size measurements indicated that there were more small bacteria in the anterior than the posterior trophosome. Bacterial division, though rarely seen, was more common in the anterior trophosome. Bulk chemical analysis of the two trophosome regions showed that sulfur (essential in the bacterial symbiont metabolism) and zinc were more concentrated in the anterior tissues, whereas 31 other major and minor elements were more concentrated in the posterior region. The existence and significance of a physiological gradient in the vestimentiferan trophosome is discussed.

Ultrastructural Changes of the Symbiotic Chlorella-Like Alga Isolated from Hydra Viridis

1982 ◽  
Vol 40 ◽  
pp. 320-321
Author(s):  
K.W. Lee ◽  
R.H. Meints ◽  
D. Kuczmarski ◽  
J.L. Van Etten
Keyword(s):  
Time Course ◽  
Reciprocal Cross ◽  
Ultrastructural Level ◽  
Ultrastructural Changes ◽  
Symbiotic Relationship ◽  
Cell Recognition ◽  
Green Hydra ◽  
Different Strains ◽  
Hydra Viridis

The physiological, biochemical, and ultrastructural aspects of the symbiotic relationship between the Chlorella-like algae and the hydra have been intensively investigated. Reciprocal cross-transfer of the Chlorellalike algae between different strains of green hydra provide a system for the study of cell recognition. However, our attempts to culture the algae free of the host hydra of the Florida strain, Hydra viridis, have been consistently unsuccessful. We were, therefore, prompted to examine the isolated algae at the ultrastructural level on a time course.

Permeability of Endometrial Blood Vessels to Exogenous Horse Radish Peroxidase in Mice. Electron Microscope Study

1973 ◽  
Vol 31 ◽  
pp. 562-563
Author(s):  
M.C. Castillo-Jessen ◽  
A. González-Angulo
Keyword(s):  
Electron Microscopy ◽  
Blood Vessels ◽  
Electron Microscope Study ◽  
Ultrastructural Level ◽  
Low Molecular Weight ◽  
Horse Radish Peroxidase ◽  
Intravascular Injection ◽  
Normal Morphology ◽  
Functional Implications ◽  
Low Molecular Weight Proteins

Information regarding the normal morphology of uterine blood vessels at ultrastructural level in mammals is scarce Electron microscopy studies dealing with endometrial vasculature despite the functional implications due to hormone priming are not available. Light microscopy observations with combined injection of dyes and microradiography along with histochemical studies does not enable us to know the detailed fine structure of the possible various types of blood vessels in this tissue. The present work has been designed to characterize the blood vessels of endometrium of mice as well as the behavior of the endothelium to injection of low molecular weight proteins during the normal estrous cycle in this animal. One hundred and forty female albino mice were sacrificed after intravascular injection of horse radish peroxidase (HRP) at 30 seconds, 5, 15, 30 and 60 minutes.

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