SOME CORTICOLOUS ALGAE OF MCMINN COUNTY,TENNESSEE, U.S.A.1

Eisrhty-one unialgal isolates comprising 10 genera (Chlorophygeae, Cyanophyceae, Xanthophyceae) were cultured from samples of tree bark scrapings removed from 5 species of trees on the campus of Tennessee Wesleyan College in Athens, Tennessee, U.S.A.     

Transporting Ocean Viromes: Invasion of the Aquatic Biosphere

Studies of marine viromes (viral metagenomes) have revealed that DNA viruses are highly diverse and exhibit biogeographic patterns. However, little is known about the diversity of RNA viruses, which are mostly composed of eukaryotic viruses, and their biogeographic patterns in the oceans. A growth in global commerce and maritime traffic may accelerate spread of diverse and non-cosmopolitan DNA viruses and potentially RNA viruses from one part of the world to another. Here, we demonstrated through metagenomic analyses that failure to comply with mid-ocean ballast water exchange regulation could result in movement of viromes including both DNA viruses and RNA viruses (including potential viral pathogens) unique to geographic and environmental niches. Furthermore, our results showed that virus richness (known and unknown viruses) in ballast water is associated with distance between ballast water exchange location and its nearest shoreline as well as length of water storage time in ballast tanks (voyage duration). However, richness of only known viruses is governed by local environmental conditions and different viral groups have different responses to environmental variation. Overall, these results identified ballast water as a factor contributing to ocean virome transport and potentially increased exposure of the aquatic bioshpere to viral invasion.     

Identification of the plasmid-encoded immunity protein for colicin El in the inner membrane of Escherichia coli

A set of plasmids containing portions of the Col El plasmid were transformed into recA⁻ cells. These cells, after UV irradiation, only incorporate labelled amino acids into plasmid-encoded proteins. UV-irradiated cells label a 14.5 kDa band if they are phenotypically immune to colicin E1, and do not contain this band if they are sensitive to colicin E1. We conclude that the 14.5 kDa protein is the colicin E1 immunity protein. When the inner and outer membranes of these cells are fractionated, the labelled band appears in the inner membrane. The immunity protein must be an intrinsic inner membrane protein, confirming the predictions made by hydrophobicity calculations from primary sequence data.MaxicellCol El plasmidImmunity proteinHydrophobicity calculation     

Characterization of the antigens involved in serotyping strains ofCampylobacter jejuni by passive hemagglutination

Components of outer membrane preparations, heated saline extracts, and phenolwater lipopolysaccharide extracts obtained from strains ofCampylobacter jejuni representing seven passive hemagglutination serotypes (Penner serotypes 1–4, 13, 16, and 50) were electrophoresed in sodium dodecyl sulfate-polyacrylamide gels. Tests of gel eluates demonstrated that lipopolysaccharide antigens are involved in serotypingC. jejuni by passive hemagglutination and that other cell surface components have no activity. This finding was confirmed by hemagglutination inhibition. In the typing ofC. jejuni by passive hemagglutination, each serotype is probably defined by the presence of one or more specific lipopolysaccharides. These findings may lead to a clarification of the serotyping nomenclature for those systems that depend on passive hemagglutination. It is recommended that a single internationally agreed numbering system be adopted for lipopolysaccharides derived fromC. jejuni.     

A factor synthesized by rabbit periosteal fibroblasts stimulates bone resorption and collagenase production by connective tissue cells in vitro

Unstimulated monolayer cultures of confluent rabbit periosteal fibroblasts synthesize a factor that stimulates bone resorption in vitro. Furthermore it stimulates rabbit chondrocytes and mouse osteoblasts to synthesize collagenase. The factor has no effect on dead bone in culture, and its activity on live bone is mediated principally by osteoclasts, since it is 75% inhibited by salmon calcitonin. Characterization of the factor by gel filtration and isoelectric focusing indicates an M_r in the range 15 000–25 000 and a pI corresponding to approx. pH 4.7. These biological and physicochemical properties are similar to those reported for a factor released by peripheral blood monocytes. However, whereas human monocyte factor in both the crude and partially-purified state exhibits interleukin-1 activity, crude and fractionated periosteal fibroblast-conditioned medium does not. This is the first report of a conditioned medium containing a molecule like the monocyte-factor which appears to have no interleukin 1 activity. The factor may be synthesized by a wide range of cell types, and could have an important role in mediating connective tissue degradation during both physiological and pathological resorption.