Influence of Al on growth, cell size and content of intracellular water of Arthrobacter sp PI/1-95

A distinct inhibition of the growth of a typical soil-born bacterium, Arthrobacter sp. PI/1-95, by aluminium was established. The content of intracellular water and (consequently) the cell size of the bacterium significantly increased when cells came into contact with aluminium. Both parameters were also increased when applying HCl, but Al caused the greater change, so that a distinct discrimination between the effects of aluminium on the one hand and a sole pH-effect on the other hand was possible. The presented results point to an osmo-regulative disorder connected with a malfunction of cell membrane and cell wall, which seems to be a probable mechanism for an Al-toxicity in connection with Arthrobacter sp. PI/1-95.