Within the hyper-arid Atacama Desert, one of the driest parts of the world, 10 sites

with differing altitude and distance to the shore were sampled along a total air-line distance (from south to north) of ~1,100 km. Opaganib supplier Filamentous cyanobacteria belonging to Nostocophycideae and Synechococcophycideae were present. Oscillatoriophycideae exhibited the highest species richness among the subclasses of cyanobacteria, and included mostly filamentous species along with some coccoids (e.g., Chroococcidiopsis). Thirty species-level phylotypes could be recognized using a cut-off of 99% 16S rRNA sequence similarity within the 22 genera defined at 97% 16S rRNA sequence similarity. Eight of the 30 taxa could be detected by both clonal and culture sequences. Five taxa were observed only in cultures, whereas the cloning approach revealed 17 additional taxa, which might be in the collection Selleck BMS-777607 but unsequenced, hard-to-cultivate, or entirely unculturable species using standard cultivation media. The Atacama Desert soils have a high diversity of phylotypes, among which are likely both new genera and new species awaiting characterization and description. “
“Klebsormidium crenulatum (Kütz.) Lokhorst (Klebsormidiophyceae, Streptophyta)

isolated from an alpine soil in Tyrol, Austria, was experimentally exposed to desiccation under various relative air humidities (RH 5, 75, and >95%, ambient air 55%–60%). The effects on the structure and ultrastructure of K. crenulatum after 1, 4, or 7 d of desiccation at 5, 75, and >95% RH were investigated. The cross walls were deformed to an undulated shape, and the cell diameter was reduced to ∼60% of the control. Regardless

of the RH applied, in all cases the cytoplasm appeared denser click here compared to that of liquid-culture-grown cells. Electron-dense particles with diameters of 0.4 μm–0.8 μm were observed in the cytoplasm, likely representing lipid droplets. The chloroplasts of desiccated samples contained a large number of plastoglobules. The number and appearance of mitochondria were not visibly altered, as also verified by 3,3′ dihexyloxacarbocyanine iodine (DIOC6) staining. The amphiphilic styryl dye FM 1-43 resulted in staining of the plasma membrane in cells from liquid culture. In 7 d desiccated samples, a marked fluorescence is seen in ∼40%–50% of the cells, which were dead. Actin microfilaments (MFs) were drastically disrupted after desiccation; only dotlike actin batches remained. These results demonstrate that flexibility of the cell walls and maintenance of the key organelles play a key role in the tolerance of desiccation stress in K. crenulatum.