1.Rubber Research Institute; Chinese Academy of Tropical Agricultural Sciences; Key Laboratory of Physiology for Tropical Crops of Ministry of Agriculture; Danzhou 571737; China;2.Department of Microbiology and Immunology; College of Biol 在期刊界中查找 在百度中查找 在本站中查找
Department of Environmental Science and Engineering; State Key Joint Laboratory of Environment Simulation and Pollution Control,Tsinghua University,Beijing 100084,Chian 在期刊界中查找 在百度中查找 在本站中查找
Department of Microbiology and Immunology; College of Biological Sciences; China Agricultural University; Key Laboratory of Agro-Microbial Resource and Application; Ministry of Agriculture; Beijing 100094; China 在期刊界中查找 在百度中查找 在本站中查找
Affiliation:
Fund Project:
National Programs for High Technology Research and Development of China (2003AA241150)
Sodium ion with high concentration is toxic to living cells, and microorganisms adapt to the environment containing high concentration of salt by the strategies of salt-in-cytoplasm and compatible solutes. The Na+ extrusion system plays important roles in maintaining cytoplasmic Na+ homeostasis and pH level in microbial cells. Two possible mechanisms of Na+ circulation across the cytoplasmic membrane have been proposed, namely primary Na+ pump and secondary Na+/H+ antiporter. Primary sodium pumps coupled the extrusion of Na+ to respiration, and the activity of which was insensitive to uncoupler CCCP (carbonyl-cyanide m-chlorophenylhydrazone). There were two types of secondary Na+/H+ antiporters-encoding genes designated single gene and multiple subunits, respectively. The types of transportation systems for Na+, possible mechanisms of Na+ extrusion, and projects for further study in bacteria are reviewed.