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The Journal of Cell Biology  1965;24(1):39-55.
An electron microscope study on the cell wall of the diatom Cylindrotheca fusiformis was carried out using stereoscopic and sectioning techniques. Material prepared by an enzyme treatment or by a mechanical method showed that the wall consists of two major components: a silica shell and organic material. Vapor of hydrofluoric acid was employed to remove the silica and thereby reveal the arrangement of the organic material. An attempt was made to increase the contrast of the organic component by "staining." Uranylacetate not only increased the electron opacity of the organic material but also apparently decreased the electron opacity of the silica shell. In ultrathin sections of complete cells, the structure as revealed by stereoscopy could be confirmed and extended. Every part of the silica shell is tightly enclosed by organic material. In the valve region the silica enclosed in this way is located between other layers of organic material. The whole cell wall is surrounded by a mucilaginous substance which stains with ruthenium red.
PMCID: PMC2106562  PMID: 14286296
4.  Phylogenetic analyses of some extremely halophilic archaea isolated from Dead Sea water, determined on the basis of their 16S rRNA sequences. 
Applied and Environmental Microbiology  1996;62(10):3779-3786.
Twenty-two extremely halophilic aerobic archaeal strains were isolated from enrichments prepared from Dead Sea water samples collected 57 years ago. The isolates were phenotypically clustered into five different groups, and a representative from each group was chosen for further study. Almost the entire sequences of the 16S rRNA genes of these representatives, and of Haloarcula hispanica ATCC 33960, were determined to establish their phylogenetic positions. The sequences of these strains were compared to previously published sequences of 27 reference halophilic archaea (members of the family Halobacteriaceae) and two other archaea, Methanobacterium formicicum DSM 1312 and Methanospirillum hungatei DSM 864. Phylogenetic analysis using approximately 1,400 base comparisons of 16S rRNA-encoding gene sequences demonstrated that the five isolates clustered closely to species belonging to three different genera--Haloferax, Halobacterium, and Haloarcula. Strains E1 and E8 were closely related and identified as members of the species Haloferax volcanii, and strain E12 was closely related and identified as a member of the species Halobacterium salinarum. However, strains E2 and E11 clustered in the Haloarcula branch with Haloarcula hispanica as the closest relative at 98.9 and 98.8% similarity, respectively. Strains E2 and E11 could represent two new species of the genus Haloarcula. However, because strains of these two new species were isolated from a single source, they will not be named until additional strains are isolated from other sources and fully characterized.
PMCID: PMC168186  PMID: 8837434
7.  Plasmids in diatom species. 
Journal of Bacteriology  1991;173(18):5924-5927.
We have discovered plasmids in 5 of 18 diatom species surveyed. In several species, more than one type of plasmid is present. Several of the plasmids show similarity by hybridization previously characterized plasmids in Cylindrotheca fusiformis (J. D. Jacobs et al., unpublished data). Additionally, there is similarity between the plasmids found in C. fusiformis and chloroplast DNA in three diatom species. These results add to the evidence that the plasmids have features of mobile genetic elements.
PMCID: PMC208330  PMID: 1885558

Results 1-7 (7)