Osmotic regulation of marine protozoa, Thraustochytrium, and demand for Na+

Osmotic regulation of marine protozoa, Thraustochytrium, and demand for Na+

Thraustochytrium is a lower fungus that grows in a large amount of Na ⁺ environment. Na ^{+ is} involved in cell osmotic regulation and cellular metabolism. Osmotic adjustment is accomplished by absorbing inorganic ions from the environment or by varying the concentration of soluble substances in the cytoplasm. Osmotic regulation through the plasma membrane is very important in the transport process. However, it is unclear how osmotic adjustment through the plasma membrane is performed in marine protists.

Australian scientist Shabala et al. used non-invasive micro-testing techniques to reveal the ionic mechanism of osmotic adjustment of the marine native organism Thraustochytrium. It was found that hypotonicity caused significant outflow of Na ⁺ , Cl ^- and K ⁺ from Thraustochytrium, and osmotic adjustment was completed within 30 min of the initial stress. For this bacterium, Na ⁺ is the main contributor, more than half in osmotic adjustment, and Cl ^- is the second contributor. The role of K ⁺ in the osmotic adjustment process is relatively small. The changes in Ca ²⁺ and H ⁺ flow rates are mainly due to intracellular signal transduction. The ion flow data was compiled by growth experiments, and even when grown in an environment without Na ⁺ , as long as the proper osmotic potential is maintained, that is, when mannitol regulates the same osmotic potential as seawater, the Thraustochytrium cells can still be normal. Growing. This indicates that Na ⁺ is not essential for the growth of Thraustochytrium, because Na ^{+ is} mainly involved in cell metabolism.

This work provides evidence for how bacteria undergo osmotic adjustment, and found that Thraustochytrium cells can grow normally in the absence of Na ⁺ , demonstrating that the cell's permeation/expansion can be regulated and regulated by other means. .

Key words: non-invasive micro-test technique (MIFE), H+ flux, Na+ flux, K+ flux, Cl- flux, thraustochytrid

Read the full text: marine protists broken capsule chytrid fungus and osmotic regulation of the Na + demand Osmotic adjustment and requirement for sodium in marine protist thraustochytrid