MODE OF ACTION OF LINENSCIN OC2 AGAINST LISTERIA-INNOCUA

Linenscin OC2 is a small hydrophobic substance produced by the orange cheese coryneform bacterium Brevibacterium linens OC2, Linenscin OC2 i nhibits growth of gram-negative bacteria with an altered outer membran e permeability and gram-positive bacteria. It is also able to lyse euc aryotic cells. The mode of action of linenscin OC2 on the Listeria inn ocua cytoplasmic membrane and the effects of environmental parameters were investigated. Addition of low doses of linenscin OC2 resulted in an immediate perturbation of the permeability properties of the cytopl asmic membrane and of the bacterial energetic state. Linenscin OC2 ind uced a loss of cytoplasmic potassium, depolarization of the cytoplasmi c membrane, complete hydrolysis of internal ATP, efflux of inorganic p hosphate, and transient increase in oxygen consumption, Potassium loss occurred in the absence of a proton motive force and was severely red uced at low temperatures, presumably as a result of increased ordering of the lipid hydrocarbon chains of the cytoplasmic membrane. We propo se that linenscin OC2 interacts with the cytoplasmic membrane and that the permeability changes observed at low doses reflect the formation of pore-like structures in this membrane.