Relation of Glutamate Transport to Growth of Alkalophilic Bacillus Species

Abstract

A mutant which required glutamate for growth as the sole nitrogen source was derived from alkalophilic Bacillus No. 8-1 by UV irradiation. The relationship was examined between cell growth and glutamate transport into cells.
Cell growth and glutamate transport into cells were dependent on extracellular pH in the presence of Na⁺, and both were maximum between pH 9 and 10. The quantitative relation between specific growth rate and glutamate uptake rate indicated that the amount of glutamate required for growth at pH 7 and 9 was consistent with that of glutamate transported at pH 7 and 9, respectively. But the amount of glutamate transported at pH 7 was not sufficient to support growth at pH 9. The glutamate transport system of this mutant strain evidently had an effect on growth.