Changes in culture medium pH by cell suspension cultures of Dioscorea deltoidea

The effect of initial pH of the culture medium (pH_i) on growth, changes in pH of culture medium (pH_c) and respiration of Dioscorea deltoidea cells was studied in cycle of batch cultivation. At pH_i 3.50 the lag phase of growth and respiration was about 24 h. Within the pH_i-range of 4.30–6.15 no lag phase was observed, growth and respiration being similar. At pH_i-values of 2.00–2.50 and 8.00 the cell population died. At pH 3.50–6.15 the level of pH_c was shifted to 4.6–4.7 by cells within 10–48 h. We suppose that the pH-regulation at pH_i range of 3.50–6.15 by the cells to a definite value of the pH_c (4.6–4.7) ensures their normal growthy cycle.