Relationship between cardiolipin metabolism and oxygen availability in Bacillus subtilis ☆

摘要

We report changes of the content of anionic phospholipids in Bacillus subtilis in response to hypoxic conditions and inhibition of terminal respiration. Cardiolipin accumulates rapidly when bacteria are suspended in non-growth medium under reduced aeration or exposed to the inhibitor cyanide; the increase of cardiolipin occurs at the expense of its precursor phosphatidylglycerol and is temperature-dependent. Depending on the extent of hypoxic stress, membranes containing different levels of cardiolipin can be isolated from B. subtilis cells. The NADH oxidase activity in cardiolipin-enriched membranes is cyanide-resistant; furthermore O₂ consumption measurements indicated that cardiolipin-enriched cells are resistant to cyanide. Results point out a possible interdependence between the effect of cyanide on cardiolipin metabolism and the effect of cardiolipin on the effectiveness of cyanide inhibition.Highlights? Bacillus subtilis lipids were analyzed by TLC and MALDI-TOF/MS. ? Hypoxic stress stimulates the conversion of PG in CL. ? Membrane CL levels correlate with the extent of hypoxic stress. ? The respiratory poison cyanide induces CL membrane enrichment. ? CL-rich cells or membranes are resistant to cyanide.