FIG. 3.

VTA cumulatively recovered in successive extractions (washings) of a culture of M. voltae PS-2. The recipient strain was PS-3. Selection was for histidine independence. F₀, filtered culture supernatant; F₁ through F₅, filtrates of supernatants obtained in five washing cycles; F_p, filtrate of the last resuspended pellet. The culture (52 ml, 2 × 10⁸ cells per ml), was resuspended each time in 10 ml of 0.3 M NaCl–0.015 M sodium citrate. The total his⁺ VTA recovered was 4.3 × 10⁶.