15 research outputs found
Investigating the chemical stabilization of hazardous waste material (fly ash) encapsulated in Portland cement
Isolation Forest as an Alternative Data-Driven Mineral Prospectivity Mapping Method with a Higher Data-Processing Efficiency
Utilization of Brine Sludge and Fly Ash Waste as Complementary Resources, for Making Non-toxic, Geopolymeric (Cement-Free) Materials
Delay-driven instability and ecological control in a food-limited population networked system
Structural Behavior of Masonry Panels Strengthened Using Geopolymer Composites in Compression Tests
Endothelium Trans Differentiated from Wharton's Jelly Mesenchymal Cells Promote Tissue Regeneration: Potential Role of Soluble Pro-Angiogenic Factors
Validation of a Modified Child-Turcotte-Pugh Classification System Utilizing Insulin-Like Growth Factor-1 for Patients with Hepatocellular Carcinoma in an HBV Endemic Area
The PVC superphylum: exceptions to the bacterial definition?
The PVC superphylum is a grouping of distinct phyla of the domain bacteria proposed initially on the basis of 16S rRNA gene sequence analysis. It consists of a core of phyla Planctomycetes, Verrucomicrobia and Chlamydiae, but several other phyla have been considered to be members, including phylum Lentisphaerae and several other phyla consisting only of yet-to-be cultured members. The genomics-based links between Planctomycetes, Verrucomicrobia and Chlamydiae have been recently strengthened, but there appear to be other features which may confirm the relationship at least of Planctomycetes, Verrucomicrobia and Lentisphaerae. Remarkably these include the unique planctomycetal compartmentalized cell plan differing from the cell organization typical for bacteria. Such a shared cell plan suggests that the common ancestor of the PVC superphylum members may also have been compartmentalized, suggesting this is an evolutionarily homologous feature at least within the superphylum. Both the PVC endomembranes and the eukaryote-homologous membrane-coating MC proteins linked to endocytosis ability in Gemmata obscuriglobus and shared by PVC members suggest such homology may extend beyond the bacteria to the Eukarya. If so, either our definition of bacteria may have to change or PVC members admitted to be exceptions. The cases for and against considering the PVC superphylum members as exceptions to the bacteria are discussed, and arguments for them as exceptions presented. Recent critical analysis has favoured convergence and analogy for explaining eukaryote-like features in planctomycetes and other PVC organisms. The case is made for constructing hypotheses leaving the possibility of homology and evolutionary links to eukaryote features open. As the case of discovery of endocytosis-like protein uptake in planctomycetes has suggested, this may prove a strong basis for the immediate future of experimental research programs in the PVC scientific community