FIG. 1.

Growth of Haloarcula sp. strain D1 on 4HBA. OD₅₅₀s in cultures containing 4HBA (▴) and in controls containing no added substrate (▵; background growth on 100 mg of yeast extract liter⁻¹ in medium), along with substrate concentrations in cultures (•) and sterile controls (○), are shown. Low concentrations of GA (▪) were detected during the late logarithmic and early stationary phases of growth. The data shown are the means of triplicate determinations; the error bars represent ±1 standard deviation.