Staphylothermus - Cell Structure

Cell Structure

Staphylothermus marinus has a unique morphology. When nutrient levels are low, it forms grape-like clusters that range in diameter from 0.5–1.0 mm up to 100 clusters large. At high nutrient levels, large clustered cells up to 15 mm in diameter are found. The S-layer is made of a glycoprotein called tetrabrachion. Tetrabrachion is stable at high temperatures and resistant to chemicals that typically denature proteins. Tetrabrachion is built from 92,000 kDa polypeptides forming projections that react with other tetrabrachion sub units making a lattice framework that covers the cell. Tetrabrachion is resistant to heat and chemical denaturation. S. marinus has a circular chromosome with 1,610 protein-coding genes and 49 RNA genes. Staphylothermus hellenicus does not have tetrabrachion in the cell wall. It is an aggregated coccus, obligate anaerobe, heterotrophic, archeon that grows 0.8–1.3 μm in diameter. It forms large aggregates with up to 50 cells and has a circular chromosome that contains 158,0347 nucleotides, 1,599 protein-coding genes and 50 RNA genes.