[Biphasic nature of the light-dependent transport of C14-alanine into Halobacterium holobium cells]

Biphase character of photoinduced pH change in H. halobium R1 suspension cells is shown: in the first illumination period pH rises and only afterwards it decreases. pH increase is accompanied by the introduction of C14-alanine into the cells, while the decrease by its yield up to the level lower than the "dark" one ("negative" photoeffect). The bi-phase character of transport processes seems to be explained by the reversible character of light-dependent bacteriorodopsin proton pump in H. halobium R1 cells.